The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a...

269
The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario by Anne Li A thesis submitted in conformity with the requirements for the degree of Masters of Health Science in Clinical Engineering Institute of Biomaterials and Biomedical Engineering University of Toronto © Copyright by Anne Li 2015

Transcript of The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a...

Page 1: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in

Ontario

by

Anne Li

A thesis submitted in conformity with the requirements for the degree of Masters of Health Science in Clinical Engineering

Institute of Biomaterials and Biomedical Engineering University of Toronto

© Copyright by Anne Li 2015

Page 2: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

ii

The Formulation of a Comprehensive Strategy for Computed

Tomography Radiation Dose Optimization in Ontario

Anne Li

Masters of Health Science in Clinical Engineering

Institute of Biomaterials and Biomedical Engineering

University of Toronto

2015

Abstract

As the awareness for the cancer risks associated with diagnostic computed tomography (CT)

exams rise, countries and institutions have begun to prioritize dose optimization. Currently,

Ontario’s only regulation for CT operation does not address dose management. This study aimed

to develop an achievable and comprehensive model for CT dose management regulations in

Ontario. A relationship analysis of evaluation results from the Regulatory Assessment for CT

(RACT 2) and dose level comparisons was performed to elicit factors that are predictive of

highly effective regulations. Qualitative interviews with jurisdictional representatives,

radiologists and medical physicists extracted the facilitators and barriers to uptake of CT

regulations. Ontario’s model contained minimum requirements to initiate dose management

efforts, and four possible dose optimization specific approaches, which are diagnostic reference

levels, compliance monitoring, peer-review process and radiation protection committee. It is

recommended that at least one specific approach be adopted by Ontario’s new CT dose

management regulations.

Page 3: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

iii

Acknowledgments

I would like to take this opportunity to thank a number of individuals, more than can be mentioned here.

This project would not have been possible without your support and contributions.

First and foremost, I would like to extend my gratitude to my supervisor, Dr. Tony Easty. Thank you for

giving me the freedom to find my own path, and the invaluable guidance you offered when needed. Your

positivity and support through the unanticipated changes to the study plan has been greatly appreciated.

You have set an example of excellence as a researcher, mentor and instructor.

I would also like to thank my supervisory committee: Dr. Narinder Paul, Dr. Emily Seto and Dr. Patricia

Trbovich, for your expertise and insightful questions that helped shape this study. You have been

generous with your knowledge and time. Thank you, Dr. Mohammad Islam, for your time in serving as

my external examiner.

I am deeply indebted to Mark Fan for your help in the seemingly endless literature search, and for your

role as second reviewer in developing the assessment instrument, not to mention the brilliant suggestion

of naming it “RACT”. Your outrageously interesting ideas made the long design process for RACT fun.

I owe many thanks to the various jurisdictional representatives, radiologists and medical physicists who

contributed their perspectives on the very important issue of CT dose management. Coordinating phone

calls across multiple time zones was not easy, but your commitment to patient protection was inspiring.

This study would not have been possible without you.

Additionally, I would like to thank my fellow clinical engineering students. I could not have asked for a

better class to share this two-year journey with. I look forward to our future adventures.

Finally, I am eternally grateful for my beloved family. Mom and dad, your unfaltering confidence in my

work, unconditional love and constant encouragement empowered me to reach my potential. I could not

have done it without you! Thank you to my dogs, Prince and Cookie, for keeping me company and

making me smile during stressful times.

Page 4: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

iv

Table of Contents

Abstract ........................................................................................................................................................ ii

Acknowledgments ...................................................................................................................................... iii

Table of Contents ....................................................................................................................................... iv

List of Tables ............................................................................................................................................... x

List of Figures ........................................................................................................................................... xiii

List of Appendices .................................................................................................................................... xix

List of Abbreviations ................................................................................................................................ xx

1 Introduction ......................................................................................................................................... 1

1.1 Motivation ..................................................................................................................................... 1

1.2 Research Objectives ...................................................................................................................... 2

1.2.1 Overall Goal and Approach .................................................................................................. 2

1.2.2 Central Hypothesis and Research Questions ......................................................................... 2

1.2.3 Specific Objectives ............................................................................................................... 3

1.3 Thesis Roadmap ............................................................................................................................ 3

2 Literature Review .............................................................................................................................. 4

2.1 History of CT Scanners ................................................................................................................. 4

2.2 System Design of MDCT .............................................................................................................. 6

2.2.1 Gantry ................................................................................................................................... 7

2.2.2 X-ray Tube and Generator ................................................................................................... 8

2.2.3 Detector Design................................................................................................................... 10

2.2.4 Data Transmission and Image Reconstruction .................................................................... 11

2.3 Ionizing Radiation and Cancer Risk ........................................................................................... 13

2.4 Radiation Dose Output Measurement Metrics ............................................................................ 15

2.4.1 CT Dose Index (CTDI) ....................................................................................................... 15

2.4.2 Volume CT Dose Index (CTDIvol) ...................................................................................... 16

Page 5: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

v

2.4.3 Dose Length Product (DLP) ............................................................................................... 16

2.4.4 Effective Dose (E) ............................................................................................................... 16

2.5 Technological Methods for Dose Optimization .......................................................................... 17

2.5.1 Effects of Technical Parameters on Radiation Dose ........................................................... 17

2.5.2 Built-in Technologies for CT Scanners............................................................................... 18

2.5.3 Dose Saving Technologies for All CT Platforms ............................................................... 20

2.5.4 Limitations of Dose Saving Technologies .......................................................................... 21

2.6 Radiation Dose Optimization Strategies ..................................................................................... 22

2.6.1 History of Jurisdictional Dose Optimization Regulations................................................... 22

2.6.2 Legislation ........................................................................................................................... 23

2.6.3 Supplemental Documents ................................................................................................... 24

2.6.4 Institutional Dose Optimization Strategies ......................................................................... 24

2.7 Current Regulatory Framework for CT Standards in Ontario..................................................... 25

3 Study Design ...................................................................................................................................... 28

3.1 Original Study Plan ..................................................................................................................... 28

3.2 Final Study Plan .......................................................................................................................... 28

4 Comprehension of the Jurisdictional Regulatory Frameworks .................................................... 30

4.1 Selection Criteria ........................................................................................................................ 30

4.1.1 Preliminary Selection .......................................................................................................... 30

4.1.2 Expanded Jurisdiction Selection ......................................................................................... 32

4.2 Identification of Relevant Publications ....................................................................................... 35

4.3 Understanding the Jurisdictional Regulatory Structure .............................................................. 39

4.3.1 Expert Interviews with Jurisdictional Representatives ....................................................... 39

4.3.1.1 Interview Questions Generation ...................................................................................... 39

4.3.1.2 Recruitment Strategy....................................................................................................... 40

4.3.1.3 Study Population ............................................................................................................. 40

4.3.1.4 Setting and Procedure ..................................................................................................... 42

4.3.1.5 Data Analysis .................................................................................................................. 42

Page 6: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

vi

4.3.2 Construction of Regulatory Structure Flow Diagrams ........................................................ 42

4.4 Discussion ................................................................................................................................... 44

4.4.1 International Radiation Protection Organizations ............................................................... 44

4.4.2 European Countries ............................................................................................................. 45

4.4.3 Australia .............................................................................................................................. 47

4.4.4 North American Jurisdictions ............................................................................................. 48

4.4.5 Developing Jurisdictions ..................................................................................................... 49

4.4.6 Japan ................................................................................................................................... 50

4.5 Summary ..................................................................................................................................... 50

5 Assessment Framework Development............................................................................................. 51

5.1 RACT 1 Design Methodology .................................................................................................... 51

5.1.1 Identification of Themes in the Radiation Protection Publications ..................................... 51

5.1.2 Identification of Domains for RACT 1 ............................................................................... 52

5.1.3 Application of RACT 1 ....................................................................................................... 54

5.1.4 Results and Discussion of Preliminary Analysis using RACT 1 ........................................ 54

5.1.5 Limitations of RACT 1 and Lessons Learned ..................................................................... 56

5.1.5.1 Difference in Document Types ....................................................................................... 56

5.1.5.2 Low Reliability of Likert Scales ..................................................................................... 56

5.1.5.3 Ambiguity of Themes and Domains ............................................................................... 57

5.2 RACT 2 Design Methodology .................................................................................................... 57

5.2.1 Development of the Comprehensiveness Checklist ............................................................ 57

5.2.2 Legislation Assessment ....................................................................................................... 59

5.2.1.1 Selection of Legislation Assessment Domains ............................................................... 60

5.2.3 Supplemental Documents Assessment ................................................................................ 62

5.2.3.1 Selection of Supplemental Document Domains ............................................................. 62

5.3 Structure of RACT 2 ................................................................................................................... 67

5.3.1 Application of RACT 2’s Comprehensiveness Checklist ................................................... 67

5.3.2 Application of RACT 2’s Legislative and Supplemental Documents Assessment ............. 67

Page 7: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

vii

5.3.3 Potential Limitations of RACT 2 ........................................................................................ 68

5.4 Summary of Assessment Framework Development ................................................................... 69

6 Evaluation of Jurisdictional CT Dose Management Models ......................................................... 70

6.1 Evaluation of Radiation Publication Documents using RACT 2 ................................................ 70

6.1.1 Comprehensiveness Assessment ......................................................................................... 70

6.1.1.1 Legislative Documents Comprehensiveness ................................................................... 71

6.1.1.2 Supplemental Documents Comprehensiveness ............................................................... 78

6.1.2 Legislation Quality Assessment .......................................................................................... 84

6.1.3 Supplemental Documents Quality Assessment ................................................................... 87

6.2 Diagnostic Reference Levels Assessment ................................................................................... 89

6.2.1 Official DRLs Comparison ................................................................................................. 90

6.2.2 Peer-reviewed Dose Survey Articles .................................................................................. 98

6.2.3 Dose Level Summary ........................................................................................................ 104

6.2.3 Limitations of Dose Level Comparisons........................................................................... 105

6.3 Discussion and Analysis ........................................................................................................... 106

6.3.1 Relationship between RACT 2 Evaluations and General Dose Trends ............................ 106

6.3.1.1 Key Themes .................................................................................................................. 106

6.3.1.2 Key Domains............................................................................................................. 109

6.3.2 Need for Regulations ........................................................................................................ 111

6.3.3 Current Status of Ontario .................................................................................................. 112

6.3.4 Limitations of Evaluation .................................................................................................. 113

6.4 Summary of the Jurisdictional Evaluations .............................................................................. 114

7 Strategy Development for Radiation Protection of CT in Ontario ............................................ 115

7.1 Expert Interviews with Jurisdictional Representatives and CT Stakeholders ........................... 115

7.1.1 Family Practitioners and the Referral Process .................................................................. 115

7.1.1.1 Interview Questions Generation .................................................................................... 115

7.1.1.2 Study Population and Recruitment Strategy ................................................................. 116

7.1.1.3 Recruitment Results and Discussion ............................................................................. 116

7.1.2 Expert Interview with CT Stakeholders ............................................................................ 116

Page 8: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

viii

7.1.2.1 Interview Questions Generation .................................................................................... 117

7.1.2.2 Recruitment Strategy..................................................................................................... 117

7.1.2.3 Study Population ........................................................................................................... 118

7.1.1.4 Setting and Procedure ................................................................................................... 118

7.1.1.5 Data Analysis ................................................................................................................ 119

7.2 Analysis of Possible CT Dose Management Strategies ............................................................ 119

7.2.1 Diagnostic Reference Levels ............................................................................................ 119

7.2.1.1 Establishment of Official DRLs .................................................................................... 120

7.2.1.2 Institutional DRLs ......................................................................................................... 121

7.2.1.3 Advisory, NOT Limits .............................................................................................. 122

7.2.1.4 Low doses are just as dangerous ................................................................................... 123

7.2.1.5 Alternatives to DRLs .................................................................................................... 123

7.2.2 Important Actors in Radiation Protection of Medical Exposures ..................................... 125

7.2.2.1 Medical Physicists......................................................................................................... 125

7.2.2.2 Radiologists ............................................................................................................... 127

7.2.2.3 Radiation Technologists ................................................................................................ 129

7.2.2.4 Co-operation of the Radiology Team ........................................................................ 129

7.2.3 Clinical Justification ......................................................................................................... 130

7.2.4 Compliance Monitoring .................................................................................................... 131

7.2.4.1 Frequency of Review .................................................................................................... 131

7.2.4.2 Method of Review ......................................................................................................... 132

7.2.4.3 Content of Review ........................................................................................................ 134

7.2.4.4 Required Resources....................................................................................................... 135

7.2.5 Role of Technology in Dose Optimization ....................................................................... 136

7.2.6 Continuing Professional Development ............................................................................. 137

7.2.6.1 Large Conferences or Education Summits .................................................................... 137

7.2.6.2 Facility Specific Training .............................................................................................. 138

7.2.7 Results of Non-Compliance .............................................................................................. 139

7.3 Ontario Model for CT Dose Management Regulations ............................................................ 140

7.3.1 Considerations for Regulations ......................................................................................... 141

7.3.1.1 Resources ...................................................................................................................... 141

7.3.1.2 Acceptance from CT Stakeholders................................................................................ 141

Page 9: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

ix

7.3.1.3 Incentives ...................................................................................................................... 143

7.3.1.4 Adaptability ................................................................................................................... 144

7.3.2 CT Radiation Protection Publications Design ................................................................... 144

7.3.2.1 Minimum Theme Requirements ................................................................................... 145

7.3.2.2 Possible Regulatory Approaches .................................................................................. 147

7.5 Summary of CT Radiation Protection Model for Ontario ........................................................ 150

8 Conclusion ....................................................................................................................................... 151

8.1 Summary of Findings ................................................................................................................ 151

8.2 Anticipated Significance ........................................................................................................... 154

8.3 Future Work .............................................................................................................................. 155

9 References ........................................................................................................................................ 157

Page 10: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

x

List of Tables

Table 1: A summary of technical parameters that may affect radiation dose in CT examinations ............. 17

Table 2: A non-exhaustive selection of institutional strategies that have been implemented in an attempt

to optimize radiation exposure from CT examinations ............................................................................... 24

Table 3: An overview of the jurisdictions that are available for data analysis on the eXposureTM software.

A wide variety of jurisdictional approaches were selected to provide a broad analysis in possible radiation

dose management models, which will allow for a strong evidence-based approach to Ontario radiation

protection standards for medical exposures ................................................................................................ 31

Table 4: A summary of the jurisdictions that were included from the expanded selection process.

Jurisdictions were selected to represent a wide range of regulation strength, geography, regulatory

approach, economic development and healthcare system type ................................................................... 35

Table 5: A summary of relevant radiation protection publications for each jurisdiction that were included

in the regulatory approach analysis. Italicized documents were included in the preliminary assessment of

jurisdictions using Regulatory Assessment for Computed Tomography 1 (RACT 1), which will be

discussed in Chapter 5 ................................................................................................................................ 36

Table 6: A summary of the jurisdictions that had representatives participate in interviews, and each

interviewee's affiliation ............................................................................................................................... 41

Table 7: The preliminary categorization of themes based on select jurisdictional radiation protection

documents ................................................................................................................................................... 52

Table 8: A summary of the attributes that were presented in the GLIA and AGREE instruments. The

attributes that were translatable for RACT 1 were grouped together and re-defined to generate broader

domains ....................................................................................................................................................... 53

Table 9: Inter-rater reliability for each theme (expressed as Weighted Cohen's κ ± 95% C.I.) .................. 55

Table 10: Final aggregated domain and theme scores for each jurisdiction. The theme abbreviations are

explained in the List of Abbreviations. ....................................................................................................... 55

Table 11: Pearson correlations among the domain scores .......................................................................... 55

Table 12: A summary of the domains that were defined to evaluate the radiation protection legislation in

RACT 2 ....................................................................................................................................................... 61

Page 11: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

xi

Table 13: A summary of the common knowledge translation barriers identified in literature that obstructs

the implementation of new, validated recommended practices .................................................................. 62

Table 14: A summary of the supplemental document assessment domains. The table provides an

explanation of each domain, the related constructs used to form the domain as well as a brief explanation

of how knowledge translation barriers are overcome with strong performance within the domain. .......... 64

Table 15: A sub-theme fulfillment checklist. Jurisdictions that address at least one of the key items in a

sub-theme are marked with an "x". ............................................................................................................. 75

Table 16: A summary of the sub-theme fulfillment. Jurisdictions that address at least one key item in each

sub-theme is awarded with an "x" in that specific sub-theme. .................................................................... 81

Table 17: A summary of the data collection methodology undertaken by each jurisdiction to establish the

official DRLs .............................................................................................................................................. 91

Table 18: A comparison of Germany's official DRL values in 2003 and 2011. ......................................... 95

Table 19: A comparison of Switzerland's official DRLs in 2003 and 2011. .............................................. 96

Table 20: A comparison of the UK's official DRLs in 1999, 2003 and 2011 ............................................. 96

Table 21: A summary of peer-reviewed publications that provide insight into the dose levels of each of

the selected jurisdictions. Information is provided for the data collection and analysis method, the

publication and dose survey dates and the reported findings. ..................................................................... 99

Table 22: A summary of the CT stakeholders that participated in the semi-structured interviews .......... 118

Table 23: A summary of the minimum requirements that should be included in Ontario's CT dose

management regulations. The themes and sub-themes that were identified as mandatory in radiation

protection for medical exposures publications in the RACT 2 evaluations are discussed. ....................... 145

Table 24: A summary of the possible dose optimization regulatory approaches that are available for

Ontario's CT dose management regulations. The table summarizes the advantages, disadvantages and

recommended implementation protocol for each of the approaches. ........................................................ 148

Table F- 1: The detailed results of the legislation quality assessment for Australia, BC, California,

Euratom and Germany. The comments explain the reasons for the scores. The legislation documents

highlighted with red font in Table 5 were analyzed for the legislation assessment. ................................. 224

Table F- 2: The detailed legislation quality assessments for Ireland, India, Kenya and Ontario. The

comments provide explanations of the assigned domain scores. The legislation documents highlighted

with red font in Table 5 were analyzed for the legislation assessment. .................................................... 229

Page 12: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

xii

Table F- 3: Legislation quality was assessed for Portugal, Switzerland, Texas and the UK. Comments

provide explanations for the domain scores. The legislation documents highlighted with red font in Table

5 were analyzed for the legislation assessment. ........................................................................................ 232

Table F- 4: The quality assessment for supplemental document from Australia, BC, California and

Canada. The comments provide explanation of the assigned score, and the documents analyzed are

highlighted in green in Table 5 ................................................................................................................. 235

Table F- 5: The supplemental document quality assessment for IAEA, Ireland, India and the UK.

Explanations for the assigned scores are provided. The documents that were used in this analysis are

highlighted in green in Table 5 ................................................................................................................. 238

Table H- 1: A comparison of the average percentage fulfillment of each theme between the "strong"

jurisdictions and all jurisdictions. Kenya, who had systematically higher proposed DRL values, is

representative of a "weak" jurisdiction. .................................................................................................... 244

Page 13: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

xiii

List of Figures

Figure 1:Corresponding traverse CT images acquired at (1) 256 mAs and (b) 88 mAs with remaining

scanning parameters held constant for a 72-kg 62 year old man [7]............................................................. 1

Figure 2: Diagram explaining the use of a pencil beam detector where the x-ray tube and detector is

moved mechnically around the patient at different angles to obtain a large volume of x-ray images that

can be reconstructed to form a detailed 3-D reconstruction of the anatomical structure [17] ...................... 5

Figure 3: Schematic illustration of a dual source CT scanner ...................................................................... 6

Figure 4: A fan beam and a large array of detectors are linked to allow for a pure rotational motion as

patients receive a multi-slice CT scan [17] ................................................................................................... 7

Figure 5: Basic components of a modern CT system with linked x-ray tubes and detectors [16] ................ 8

Figure 6 (a): A conventional x-ray tube and (b) a rotating envelope tube. These schematic drawings show

the electrons that are emitted (green lines) when a high voltage is applied to the cathode plate. The x-rays

(purple arrows) are released in a perpendicular direction to the electron beam. [23] ................................... 8

Figure 7: X-rays in the plateau region of the trapezoid shaped beam will be detected by the row of

detectors, whereas the penumbral region will be blocked by the collimator. This contributes to the

synthesis of a "wasted dose" [24] ................................................................................................................. 9

Figure 8: Pre-patient collimation of the x-ray beam can be used to achieve difference slice collimations in

a single-slice CT scanner [23] ..................................................................................................................... 10

Figure 9: Fixed array detector with 16 detector rows for a 4-slice system. The right side of the diagram

depicts how slice widths of 1.0 mm can be achieved by using one detector. The left side of the schematic

shows slice widths of 4.0 mm can be achieved in the iso-center by adjusting the collimation of the beam,

and combining 4 detector signals. [25] ....................................................................................................... 11

Figure 10 (a): Design of an adaptive array detector that shows increasing element widths as the distance

from the center of the detector increases (b) Available collimations for the adaptive array detector in

Figure 8a by adjusting pre-patient collimation and combining signals of various detectors [25] .............. 11

Figure 11(a): In the frequency domain, the one-dimensional view at a particular angle is the same as the

two-dimensional Fourier transform profile of the image spectrum [27] (b) The spectrum of each view can

be integrated at a particular angle that the original slice was acquired in the spatial domain [26] ............. 12

Figure 12 (a): Back-projection schematic that shows the reconstruction of a single bright spot. The

"smearing back" of the image spectrum causes blurriness. (b) Filtered back-projection of the same image

Page 14: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

xiv

with a single bright spot. The negative spikes beside the peak and the uniform signal of the peak help to

counteract the blurriness ............................................................................................................................. 13

Figure 13: Linear attenuation co-efficient for absorbing mediums in the body [30] .................................. 14

Figure 14: A flow diagram that shows the decision-making process for the expanded selection of

jurisdictions. Bolded jurisdictions were already available in the preliminary selection process because of

available data on the eXposureTM system ................................................................................................... 33

Figure 15: Decision tree that helped to categorize the regulation strength of each jurisdiction ................. 34

Figure 16: A general influence diagram that present the approximate regulatory structure that can be

found in the radiation protection of medical applications in each jurisdiction ........................................... 44

Figure 17: The number of items fulfilled by each jurisdiction for each theme. Texas fulfilled the highest

number of items despite only fulfilling half of the total possible number of items. ................................... 71

Figure 18 (a) A heat map display to provide visualization of the percentage fulfillment of each theme by

every jurisdiction. The data is normalized to the lowest and highest percentage fulfillment in the data

(0.00% and 85.71%, respectively). (b) The breakdown of the graded colour scale used for the heat map.

Red indicates low percentage fulfillment and green represents high percentage fulfillment. .................... 73

Figure 19: A visual display to show the number of items fulfilled for each theme for every jurisdiction.

IAEA’s Basic Safety Standards comparatively fulfilled the most number of items. .................................. 78

Figure 20: A heat map display for the percentage fulfillment of each theme for every jurisdiction with

supplemental documents. The colour scale is normalized to the lowest and highest value of the dataset,

which are 0.00% and 100.00%. (b) The breakdown of the graded colour scale used for the heat map. Red

indicates low percentage fulfillment and green represents high percentage fulfillment ............................. 80

Figure 21: A heat map display to show the domain score for every jurisdiction in the legislative quality.

The highest scoring domain on average is clarity of legislative scope, with an average score of 3.1. The

highest scoring jurisdiction, on average, is Texas with an average domain score of 3.6. ........................... 84

Figure 22: A polar chart to display the legislative quality of North American jurisdictions in the analysis.

Each of the axes on the polar chart represents one domain. Larger polygonal shapes represent higher

legislative quality since each domain would require a high score to form the larger shape. ...................... 86

Figure 23: A polar chart display for the legislative quality of European jurisdictions and Australia.

Australia was included in this polar chart because it uses a similar approach to European nations.

Switzerland has the highest comparative legislative quality, which is evident in its visibly large polygonal

shape. .......................................................................................................................................................... 86

Page 15: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

xv

Figure 24: A polar chart to depict the comparative legislative quality of the developing nations. Ontario

has an almost identical shape to Kenya, where 5 of the 6 domains had the same scores and Ontario only

scored higher in the accountability domain. India’s polygonal shape is comparatively smaller to indicate

lower legislative quality. ............................................................................................................................. 87

Figure 25: A heat map display to show the domain score for every jurisdiction. The highest scoring

domain on average is clarity of scope and purpose, with an average score of 3.38. The highest scoring

jurisdiction, on average, is IAEA with an average domain score of 3.57. .................................................. 88

Figure 26: A polar chart to visualize the overall supplemental document quality for every jurisdiction.

Large heptagonal shapes infer higher quality in all domains and therefore, better-rounded supplemental

documents. .................................................................................................................................................. 89

Figure 27: The official DRL values for each jurisdiction’s head-related CT scans. Ireland has the highest

DRL value for the routine head scan at 1000 mGy-cm [128], [129], [130], [131], [132] .......................... 92

Figure 28: A graphical display to compare the face-related DRL values. Switzerland and Ireland have

higher DRL values compared to the German DRLs for specialized face-related exams [129], [130], [131]

.................................................................................................................................................................... 92

Figure 29: A comparison of the official DRLs for neck-related exams. Switzerland's DRL value for neck

exams is set 100 mGy-cm lower than the analogous neck exam DRL value for Australia [128], [130],

[132] ............................................................................................................................................................ 92

Figure 30: A comparison of the official DRLs for chest-related examinations. Ireland has comparatively

the highest DRL value for these exams, whereas Switzerland's thorax exam has the lowest DRL value

[128], [129], [130], [131], [132] ................................................................................................................. 93

Figure 31: A graphical display of the official DRL values for abdomen examinations. The first three bars

show the values for upper abdomen exams, whereas the latter three bars are for routine abdomen

examinations. [129], [130], [131], [132] ..................................................................................................... 93

Figure 32: The official DRL comparisons for pelvis-related examinations. Germany's DRL for pelvis

exams is comparatively the lowest at 450 mGy-cm. [129], [130], [131] .................................................... 93

Figure 33: A comparison of the trunk-related DRL values for the jurisdictions with official DRLs. The

first three bars indicate the DRL values for abdo-pelvis exams, whereas the latter three bars indicate the

chest-abdo-pelvis examination DRLs [128], [130], [132] .......................................................................... 94

Figure 34: A comparison of the official DRL values for lumbar-spine related exams. Germany's exams

are divided into specialized exam types, which results in comparatively lower DRL values. [128], [129],

[130] ............................................................................................................................................................ 94

Page 16: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

xvi

Figure B- 1: The regulatory structure for radiation protection in medical applications for Australia.

Similar to Canada, the licensing requirements are set by individual states. ............................................. 173

Figure B- 2: A schematic to describe CT regulations in British Columbia. BC takes a unique approach

that gives the College of Physicians and Surgeons of British Columbia legal authority to accredit CT

facilities ..................................................................................................................................................... 174

Figure B- 3: The regulatory structure for CT radiation protection in California. The dashed lines suggest

that accreditation by only one of the three listed programs is required. ................................................... 175

Figure B- 4: The regulatory structure for CT radiation protection in Germany. The local medical

authorities are appointed to oversee the compliance of CT facilities. However, they are accountable to the

state offices that are trusted with the implementation of the of the federal regulations. ........................... 176

Figure B- 5: India's regulatory structure for CT operation is very simple, and only involves the licensing

of CT facilities. The licensing process is free to reduce chances of corruption. ....................................... 177

Figure B- 6: The intended regulatory structure for CT radiation protection in Ireland. The limited

available financial and human resources resulted in the inability of the Medical Council to oversee

compliance with S.I. 478/2002. (b) The current regulatory structure in Ireland as the responsibilities to

ensure compliance with the CT standards are entrusted to a branch of the Health Services Executive. .. 178

Figure B- 7: Japan interestingly does not have any regulations designed to oversee operation of CT.

However, the Japan Network of Research and Information on Medical Exposure and other associated

organizations have realized the increasing risks associated with high doses in CT exams. This has led to

the proposal of DRLs. ............................................................................................................................... 179

Figure B- 8: Kenya's regulatory structure is simplistic. However, facilities do require licensing to operate

CT scanners and there are periodic safety assessments of the CT scanners. The assessment are focused on

the technical functionality of the CT scanners. More interestingly is, perhaps, the Afrosafe initiative that

was established to fulfill World Health Organization’s Bonn-Call for Action. ........................................ 180

Figure B- 9: Ontario's regulatory structure is only applicable to the technical standards for CT scanners.

The HARP Act and Regulations pertain to the technical functionality of operational CT scanners in

Ontario. ..................................................................................................................................................... 181

Figure B- 10: Portugal interestingly has more rigorous standards for private institutions. Public

institutions are simply expected to obtain a license at installation and it is assumed compliance with the

standards is continuous. Private institutions, however, are subjected to additional inspections and are

regulated by an additional regulation. ....................................................................................................... 182

Page 17: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

xvii

Figure B- 11: Switzerland has a very centralized regulatory structure for CT radiation protection. The

Federal Office of Public Health is responsible for oversight of CT facilities and establishment of DRLs.

.................................................................................................................................................................. 183

Figure B- 12: The Texan regulatory structure for CT radiation protection involves three sub-branches.

The inspections branch oversees compliance of the CT facilities, the licensing group grants the initial

licenses and adjusts the licensing based on inspection results, and the policy/standards and quality

assurance groups reviews the notes from inspections and follows up with the registrants and is responsible

for rulemaking. .......................................................................................................................................... 184

Figure B- 13: The United Kingdom regulatory structure is applicable to institutions from England,

Scotland and Wales. The regulations are centralized in these three regions, but the inspection authorities

vary ........................................................................................................................................................... 185

Figure D- 1: RACT 1 is simplistic in its deisgn and contains only three domains that were thought to

encompass all the important attributes of radiation protection document quality .................................... 190

Figure D- 2: Sample rater worksheets for the reviewers to record the score of each domain and theme for

every jursidiction. E represents executability; C is comprehensiveness; R is rigor .................................. 191

Figure G- 1: Official DRL values for each jurisdiction’s head-related CT exams. The CTDIvol DRLs are

comparable for all of the jurisdictions. [128], [129], [130], [131], [132] ................................................ 241-

Figure G- 2: A graphical display to compare the face-related DRL values expressed in volume CT dose

index. Germany's official DRL value for sinusitis is visibly lower compared to the other jurisdictions'

values. [129], [130], [131] ........................................................................................................................ 241

Figure G- 3: A comparison of the official DRL values in the volume CT dose index measurement for

neck-related exams. [128], [130], [132] .................................................................................................... 241

Figure G- 4: A comparison of the official DRL values for chest-related exams. Switzerland's CTDIvol

value for the general thorax scan is comparatively lower. [128], [129], [130], [131], [132] .................... 242

Figure G- 5: A graphic display of the official DRL values for abdomen-related examinations. The first

three bars are the comparative values for upper abdomen examinations, while the latter three bars are for

routine abdomen examinations. [129], [130], [131], [132] ....................................................................... 242

Figure G- 6: The official DRL comparisons for pelvis-related examinations. Ireland's routine pelvis DRL

value in CTDIVOL is notably higher. [129], [130], [131] .......................................................................... 242

Page 18: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

xviii

Figure G- 7: A comparison of trunk-related DRL values for the jurisdictions with official DRLs. The first

three bars are the CTDIvol measurements proposed as the official DRL for abdo-pelvis exams, while the

latter three bars indicate the official CTDIvol DRL value for chest-abdo-pelvis exams. ........................... 243

Figure G- 8: A comparison of the official DRL values in volume CT dose index measurements for

lumbar-spine related examinations. Germany's exams are divided into specialized exam types. ............ 243

Page 19: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

xix

List of Appendices

Appendix A: Sample Questions for Jurisdictional Representatives ................................................... 171

Appendix B: Influence Diagrams of Each Jurisdiction’s CT Radiation Protection Regulatory

Structure .................................................................................................................................................. 173

Appendix C: Bonn Call-for-Action ....................................................................................................... 186

Appendix D: RACT 1 ............................................................................................................................. 190

Appendix E: RACT 2 .............................................................................................................................. 192

Part 1: Comprehensiveness Assessment ............................................................................................... 192

Part 2: Legislation Assessment ............................................................................................................. 204

Part 3: Supplemental Documents Assessment ...................................................................................... 213

Appendix F: Legislation and Supplemental Document Quality Assessment Results ....................... 224

Part 2: Legislation Quality Assessment Results ................................................................................... 224

Part 3: Supplemental Document Quality Assessment ........................................................................... 235

Appendix G: Official DRL Comparisons in CTDIvol ........................................................................... 241

Appendix H: Comparison of Percentage Fulfillment of each Theme ................................................ 244

Appendix I: Definitions of Clinical Justification for Medical Exposure ............................................ 245

Appendix J: Sample Questions for Radiologists .................................................................................. 247

*

Page 20: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

xx

List of Abbreviations

ACR- American College of Radiology

AGREE-Appraisal of Guidelines for Research & Evaluation

ALARA- As low as reasonably achievable

AU-Australia

BC- British Columbia

CA-California

CAN-Canada

CH-Switzerland

CT- Computed tomography

CTDIvol- Volume Computed Tomography Dose Index

CTDIW- Weighted Computed Tomography Dose Index

DAP- Diagnostic Accreditation Program

DE- Germany

DLP- Dose Length Product

DRLs- Diagnostic reference levels

E- Effective Dose

EU-European Atomic Energy Community

Euratom- European Atomic Energy Community

GLIA- Guideline Implementability Appraisal

HARP- Healing Arts Radiation Protection

IAC- Intersocietal Accreditation Commission

IAEA- International Atomic Energy Agency

ICRP- International Commission for Radiological Protection

IL-Ireland

Page 21: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

xxi

IN-India

JC- The Joint Commission

J-RIME- Japan Network of Research and Information on Medical Exposure

KN-Kenya

NIRS- National Institute of Radiological Science

ON-Ontario

PACS-Picture Archiving and Communication System

PMMA-Polymethylmethacrylate

PR-Portugal

QBP- Quality Based Procedure

RACT- Regulatory Assessment for Computed Tomography

RPB- Radiation Protection Board

SSDE-Size-specific Dose Estimates

TAC- Texas Administrative Code

TX-Texas

UHN- University Health Network

UK- United Kingdom

WHO- World Health Organization

Page 22: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

1

1 Introduction

Computed tomography (CT) is a vital tool in modern medicine because it provides accurate anatomic

information in a timely manner. Its powerful diagnostic properties are now routinely applied in trauma

situations, pre-operative procedures, cancer management and guiding interventional procedures [1], [2].

The vast applications for CT scans have resulted in a growing reliance on this tool in Canada, as exhibited

in the increase of operational CT scanners from 169 in 2004 to 510 in 2012 [3]

1.1 Motivation

All x-ray technologies record the relative intensities of ionizing radiation to form a grayscale radiograph

of the structure. In CT, large volumes of these images are generated from different angles for three-

dimensional reconstructions of the structures, which correlate to a considerably larger radiation dose

compared to traditional x-rays. For example, a typical chest CT requires one hundred times more

radiation than a corresponding lung x-ray [4], [5]. The high dynamic range of exposure in CT is an

additional complication in the optimization of radiation dose because the digital detectors employed in CT

scanners do not saturate like x-ray film or conventional film, which suggests that there is no effective

indication of over exposure [6]. Figure 1a shows a high dose CT at 256 mAs while Figure 1b’s image was

generated with a lower dose of 88 mAs and yet, the diagnostic quality of both images were deemed

acceptable because the lesion was readily identifiable [7]. The challenge to radiation dose optimization is,

therefore, to identify acceptable thresholds of image quality so that minimum radiation doses can be

established to achieve diagnostically useful images.

Figure 1:Corresponding traverse CT images acquired at (1) 256 mAs and (b) 88 mAs with remaining scanning parameters held

constant for a 72-kg 62 year old man [7]

This growing reliance on CT translates into increased cancer risks. The National Research Council in the

United States formulated the Biological Effects of Ionizing Radiation (BEIR VII) model, which is

Page 23: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

2

founded upon longitudinal studies of Japanese atomic bomb survivors, that estimates one cancer per 100

people from a single exposure of 100 mSv [4], [8]. With an average estimated radiation dose of 10 mSv

for routine CT scans, this translates into an estimated cancer risk of 1 in 1000 patients [9]. A retrospective

study using the Australian Medicare system database showed that people who received CT scans in

childhood have a 24% greater risk of cancer than those who were never exposed to CT [10]. The

incidence rate ratio was also found to increase by 0.16 with each additional CT scan, with this rate being

greater in patients who received CT scans at younger ages [10].

A higher incidence of cancer risks in CT patients will occur if unnecessarily high radiation doses are

overlooked, which will directly translate into greater cancer care costs. In 2000, cancer care cost Canada

$17.4 US billion [11]. This costly consequence suggests a need to optimize radiation dose. Currently,

there are no regulations targeting CT dose management in Ontario, but the recommended approach for

medical radiation exposures is to keep doses “as low as reasonably achievable” (ALARA principle) [9],

[12]. Despite the ALARA approach, significant variation in effective doses for similar scan protocols has

been observed. For example, scanner models can cause variation by a factor of 3 while local scan

techniques and parameter selection can cause a 13-fold variation in effective dose for the same study type

[12]. Furthermore, an audit report on the management and use of diagnostic imaging equipment observed

that appropriate equipment settings for children were not used for over 50% of children’s CT diagnostic

scans in two Ontario hospitals [13]. This roughly translates into the child being exposed to eight times the

radiation an adult would be exposed to on the same setting [13]. There is a demonstrated need to establish

a strategy to limit these variations and ensure that CT doses are truly as low as reasonably achievable.

1.2 Research Objectives

1.2.1 Overall Goal and Approach

The overall goal of this study was to optimize CT patient safety in Ontario by providing the authoritative

body with recommendations for an achievable and comprehensive model for CT dose management

regulations. To this purpose, basic requirements and optional features that have been undertaken in

various jurisdictional approaches to radiation dose regulations were elucidated, and then, translated into

potential standards that can be implemented within the Ontario Healthcare system. The ultimate goal is to

improve patient safety by encouraging prioritization of radiation dose optimization as the field of

medicine increasingly relies on CT technology.

1.2.2 Central Hypothesis and Research Questions

The proposed research will answer the questions:

Page 24: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

3

Are legislative approaches effective? If so, what requirements should be included in the optimum

regulatory framework for Ontario?

The central hypothesis was that legal standards will benefit the management of CT radiation dose within a

jurisdiction. Legislation will provide the groundwork for the regulation of CT doses, but supplemental

documents such as clinical practice guides will be useful in helping CT facilities achieve compliance with

the legal standards. This hypothesis is formulated based on the need for commitment to prioritize dose

optimization from all stakeholders in the healthcare system [14]. It is hypothesized that endorsement of

radiation dose management from provincial healthcare authoritative bodies and Ontario professional

bodies (e.g. Ontario Association of Radiologists) is required to initiate prioritization of CT radiation dose

optimization at the institutional level.

1.2.3 Specific Objectives

1. Select existing jurisdictional models that account for a wide variety of approaches to regulating

CT patient radiation dose based on current knowledge, and thoroughly understand each

jurisdiction’s regulatory structure through document review and qualitative analysis.

2. Design an assessment framework for the evaluation of jurisdictional models used in CT radiation

dose regulations.

3. Evaluate the selected jurisdictional models using the assessment framework and validate the

conclusions of the framework through a general dose levels comparison.

4. Propose an achievable and comprehensive model for CT dose management in Ontario.

1.3 Thesis Roadmap

In Chapter 2 of this thesis, a literature review is provided to explain the history of CT scanners in an

attempt to better understand the significant increase in radiation dose from CT scanners. The cancer risks

from ionizing radiation and currently available dose-saving technologies are also explained. A brief look

at jurisdictional and institutional dose optimization strategies that have been undertaken, and Ontario’s

current approach to CT operation are described to provide insight into the requirements for a

comprehensive CT dose management model.

Chapter 3 briefly explains the rationale for this study. The original study design has been altered to

accommodate changes in resources. Chapter 4 provides thorough descriptions of the 13 jurisdictional

regulatory models selected for analysis that were developed from review of CT radiation protection

Page 25: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

4

documents and semi-structured interviews with a representative from each jurisdiction. The regulatory

and legislative factors that may facilitate implementation of regulatory approaches are also described.

Chapter 5 then explains the development of an assessment framework, RACT 2, which is designed to

systematically compare and evaluate jurisdictional dose optimization regulatory approaches.

In Chapter 6, the results of a comparative evaluation of the 13 jurisdictional regulatory approaches using

RACT 2 are described. Approximate dose levels comparisons were also performed, and the results are

detailed. The results of the relationship analysis between the dose levels and the RACT 2 evaluation

results are also presented. Chapter 7 describes the strategic development of an achievable and

comprehensive model for CT radiation protection in Ontario, which was developed through consideration

of the results from the relationship analysis in the previous chapter and qualitative interview with the

jurisdictional representatives, radiologists and medical physicists. Chapter 8 concludes the study by

providing a summary of findings, explaining the anticipated significance of this work and highlighting

future work that can be undertaken.

2 Literature Review

The awareness for radiation protection has increased as the radiation exposure through medical

applications have risen. Of the different modalities that use ionizing radiation, CT accounts for 49% of the

U.S. population’s radiation doses for medical exposure [15]. Furthermore, a report from the United

Nations Scientific Committee on Effects of Atomic Radiation (UNSCEAR) found that CT contributes to

about 35% of the collective dose for patients, even though it only accounts for 5% of the clinical

procedures [15]. A better understanding of the technological advances can explain the significant increase

in radiation dose from CT scanners. Available dose optimization strategies and the current status of CT

regulations in Ontario were reviewed to provide insight into possible approaches that can strengthen CT

radiation protection in Ontario.

2.1 History of CT Scanners

Computed tomography uses computer processed x-rays to produce images of specific areas of a scanned

object, which has allowed for clinicians to make diagnoses without the use of invasive methods such as

biopsies. CT scanners were first commercially developed by electrical engineer G.N. Hounsfield in 1971,

who constructed a head CT scanner with a conventional x-ray tube and a dual-row detector system that

was able to acquire 12 slices with 13 mm thickness [16]. This CT scanner concept (i.e. pencil beam) takes

a conventional x-ray picture in the starting position, then the system would rotate mechanically by one

degree before taking another x-ray picture [17]. This process, as shown in Figure 2, was repeated until the

Page 26: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

5

system performed a full helical scan around the patient, with the patient slice thickness being equivalent

to the x-ray beam thickness [17]. Although advances were made to the 1st generation CT scanners to

decrease scanning time and slice thickness, significant changes to the technology did not occur until a

new CT scanner was conceptualized to have no moving parts to have extremely fast data acquisition.

These new scanners used an electron beam source, which allowed the x-ray source point to be moved

electronically rather than mechanically and thus allowing for shorter scanning time and lower radiation

dose [18]. However, the limited image quality and high cost of electron beam source CT scanners

prevented their wide production and use [16].

Figure 2: Diagram explaining the use of a pencil beam detector where the x-ray tube and detector is moved mechanically around

the patient at different angles to obtain a large volume of x-ray images that can be reconstructed to form a detailed 3-D

reconstruction of the anatomical structure [17]

During the early 1990s, research of CT scanners continued to focus on increasing image quality and faster

acquisition times. The introduction of slip ring technology (i.e. spiral CT scanners) allowed for

continuous rotation to acquire successive slices as a patient slides through the system, which allowed

large volumes of data to be acquired such that images could be reconstructed at any position along the

patient axis [16]. The major drawbacks of this single slice spiral CT system resulted in very limited scan

ranges due to insufficient volume within one breath-hold time of the patient and missing spatial resolution

[16]. These drawbacks were resolved after the introduction of multi-slice CT systems that allowed for

larger volume coverage and improved image resolution. Multi-slice CT systems with multiple detectors

(MDCT) allowed multiple slices to be acquired concurrently, which increased image resolution and

further decreased image acquisition times. With image quality being the priority for consumers in the

early 2000s, manufacturers continued to explore the possibilities in multi-detector CT systems. In fact, the

number of slices available in multi-slice systems has increased exponentially as a function of time [16].

Page 27: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

6

At the same time, a different path of technological advancement was formed as dual-source CT systems

were conceptualized (Figure 3). These systems use two x-ray tubes and two corresponding detectors

offset by 90˚ to provide improved temporal resolution of approximately a quarter of the gantry rotation

time, which means that it is essentially independent of the patient’s heart rate [16]. This is significant for

its potential benefits for echocardiograph (ECG) controlled cardia CT protocols [19]. The two x-ray tubes

can be operated at different tube voltage settings and/or different pre-filtrations, which allows for dual-

energy acquisitions [16]. Existing literature does not suggest an increase in radiation exposure as a result

of the use of dual-energy source CT protocols [20]. Contrastingly, the post-processing flexibility and

higher informational content provides more opportunities for radiation dose savings in routine CT

protocols [20]. For example, the need for prior unenhanced scanning images is lowered due to the

increased information that can be obtained from the enhanced (i.e. contrast-enhanced) images.

Figure 3: Schematic illustration of a dual source CT scanner

Comparatively, the development of increased number of slices in MDCT is more concerning as increased

number of slices require increased radiation dose delivery. Additionally, this design results in greater

dose delivery since some amount of x-ray beam is beyond incident of the detector rows, and there is

unused radiation beyond the beginning and end of the scanning region as the subsequent detector rows

after the first one need to “catch up” before making a contribution to the image [21].

2.2 System Design of MDCT

Since the MDCT has become the norm in radiology departments in the medical world, dose optimization

efforts have been focused on this scanner type. Despite the technological advancements since the 1st

generation system, the concept for CT scanners has remain similar, with the slight differences that MDCT

uses a fan beam to cover a larger scanning area, a large array of detectors to detect the fan beam and

Page 28: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

7

continuous rotational motion of the rigidly linked x-ray beam and detector, as shown in Figure 4, to

obtain large volumes of images in shorter scanning time [17]. To obtain multiple slices and continuous

data acquisition, the patient table is also continuously translated while the scan data is being acquired.

Figure 4: A fan beam and a large array of detectors are linked to allow for a pure rotational motion as patients receive a multi-

slice CT scan [17]

2.2.1 Gantry

The gantry of a CT machine (Figure 5) refers to the frame that houses the x-ray tube, collimators and

detectors in a CT machine, which is designed to provide mechanical support for the internal components

to be moved in a circular path. The gantry also has an opening in which the patient table can be translated.

In MDCT scanners, the x-ray tube and the detector are both mounted onto the rotating gantry in a

“rotate/rotate” geometry [16]. As the gantry rotates, different views are acquired to obtain large volumes

of conventional x-ray images that can be reconstructed to form 3-dimensional anatomical structures. As

of 2007, modern MDCT systems have gantry rotation times of approximately 0.30 s and so, the gantry

must provide high stability of the focal spot and detector position and withstand high gravitational forces

[16].

Page 29: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

8

Figure 5: Basic components of a modern CT system with linked x-ray tubes and detectors [16]

2.2.2 X-ray Tube and Generator

X-ray tubes are diodes that are used to generate the x-ray photon beams. In any x-ray tube, a high voltage

is applied to the cathode, causing electrons to be emitted into a vacuum towards the anode. The electrical

current focused on the anode will collide with and accelerate other electrons, ions and nuclei within the

anode material [22]. Excited electrons move from a lower energy state to one of higher energy [22].

Approximately 1% of the energy generated from the collisions result in x-ray photons being released in a

perpendicular direction to the electrical current since precise energies are released as the excited electron

drops back down to the lower energy level [22].

Figure 6 (a): A conventional x-ray tube and (b) a rotating envelope tube. These schematic drawings show the electrons that are

emitted (green lines) when a high voltage is applied to the cathode plate. The x-rays (purple arrows) are released in a

perpendicular direction to the electron beam. [23]

There are two types of x-ray tube designs that can be used in MDCT. The first design—conventional tube

design (Figure 6a)—has a rotating anode plate of about 160-220 mm in a vacuum housing [16]. The

performance level of the x-ray tube is correlated to the heat storage capacity of x-ray tubes and the

vacuum housing, which is measured in Mega Heat units [16]. Larger anode plates have increased heat

Page 30: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

9

storage capacities since more x-ray beams can be delivered before it reaches the temperature limit. The

generated heat is mainly dissipated via thermal radiation [16], [23]. This design does not have any moving

parts of bearings in the vacuum, which allows the design to be compact and still withstand the high

gravitational forces associated with the gantry rotation [23].

The second type of x-ray tube is the rotating envelope tube as shown in Figure 6b, and its anode plate is

part of the rotating tube housing [16]. This allows the anode plate to be directly in contact with the

cooling oil. The requirement of heat storage capacity is eliminated due to the high heat dissipation rate

that can be achieved using thermal conduction with the cooling oil [16], [23]. The fast heat dissipation

also allows for performance of higher power scans in rapid succession. Unlike the conventional tube, the

rotating cathode in the rotating envelope tube requires electromagnetic deflection of the electron beam to

position and shape the focal spot on the anode [23].

A collimator is located between the x-ray tube and the patient. The purpose of this device is to adjust the

width of the x-ray beam when it reaches the patient in the iso-center of the CT scanner. X-ray fan beams

normally have a dose profile that is trapezoid shaped in the longitudinal direction [24]. X-rays from the

plateau region of the trapezoid completely illuminate the detector, whereas the penumbral region x-rays

only partly illuminate the detector since the collimator obstructs some parts of the beam as shown in

Figure 7 [24]. Modern MDCT typically only use the plateau region of the x-ray beam while the

penumbral region is then discarded by a post-patient collimator or by intrinsic collimation of the detector

elements [24]. Although this “wasted” dose does not add to the acquired image, it still gets passed

through the patient to add to the effects of ionizing radiation.

Figure 7: X-rays in the plateau region of the trapezoid shaped beam will be detected by the row of detectors, whereas the

penumbral region will be blocked by the collimator. This contributes to the synthesis of a "wasted dose" [24]

Page 31: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

10

2.2.3 Detector Design

Radiation sensitive solid-state materials, such as cadmium tungstate or gadolinium-oxide, are used in

modern CT systems [16], [23] . Detector materials are selected for good detection efficiency and short

afterglow times to complement the fast gantry rotation speeds of modern CT scanners [23]. These

materials convert absorbed x-rays into visible light, which is then detected be a silicone photodiode [23].

The photodiode converts the light into an electrical current that can be amplified and analyzed as a digital

signal [23]. Single-slice CT detector systems use pre-patient collimation of the x-ray beam to adjust the

slice widths as shown in Figure 8. However, modern MDCT systems require detector systems that can

collect data from multiple slices simultaneously. Slice widths are optimized for scan length, longitudinal

resolution, and image noise in accordance with the clinical application of the scan [16], [23], [25].

Figure 8: Pre-patient collimation of the x-ray beam can be used to achieve difference slice collimations in a single-slice CT

scanner [23]

There are two detector types that are routinely used in MDCT. The fixed array detector has small detector

elements of equal sizes in the longitudinal direction [23]. Each element defines a fixed collimated slice

width at the center of rotation. Pre-patient collimation and the summation of signals can be used to

achieve different slice widths at the iso-center of rotation [25]. For example, Figure 9 shows a 16 row

detector system for a 4-slice CT scanner. The system is suited to scan 4 slices at 1.0 mm width, and signal

combinations can then be used to obtain wider collimations of 4 slices at 2.0 mm, 4 slices at 3.0 mm and

so forth. In this detector system, the outer detector rows cannot be used individually, which results in the

actual detector being wider than the total coverage in the longitudinal direction at the iso-center [25].

Furthermore, unnecessary mechanical cuts, and optical separations between the small elements at wider

collimations result in reduced dose efficiency of the system [25].

Page 32: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

11

Figure 9: Fixed array detector with 16 detector rows for a 4-slice system. The right side of the diagram depicts how slice widths

of 1.0 mm can be achieved by using one detector. The left side of the schematic shows slice widths of 4.0 mm can be achieved in

the iso-center by adjusting the collimation of the beam, and combining 4 detector signals. [25]

An adaptive array detector design has been developed to counter the disadvantages of the fixed array

system. Adaptive array detectors comprise of detector row elements of various sizes in the longitudinal

direction to obtain a flexible selection of slice widths [23]. Figure 10 shows the design principle for this

array type, which is gradual increases in element widths as the distance from the center increases [25].

This design allows for more combinations of detector signals, an avoidance of unnecessary dead spaces,

and a greater dose efficiency [25].

Figure 10 (a): Design of an adaptive array detector that shows increasing element widths as the distance from the center of the

detector increases (b) Available collimations for the adaptive array detector in Figure 8a by adjusting pre-patient collimation

and combining signals of various detectors [25]

2.2.4 Data Transmission and Image Reconstruction

Modern MDCT scanners require data transmission systems that are capable of handling large amounts of

data in a short period of time. 45 MB/s of data can be generated in a typical 16-slice CT scanner with a

gantry rotation rate of around 0.5 seconds, whereas 180-200 MB/s of data can be generated in a 64-slice

Page 33: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

12

scanner with the same gantry rotation rate [16]. To properly handle these data rates, contactless

transmission technology such as laser or electro-magnetic transmission is used [16]. Electro-magnetic

transmission couples a rotating transmission ring antenna and a stationary receiving antenna that then

transmits the data to the image reconstruction software systems [16].

There are two popular methods that have traditionally been used for image reconstruction in MDCT

scanners. The first method, Fourier reconstruction, takes the Fourier transform of the two-dimensional

image and its associated one-dimensional views to convert the problem into the spatial or frequency

domain [26]. Central slice theorem can be used to analyze the problem in the frequency domain. In the

frequency domain, the one-dimensional view measured at a specific angle is the same as the profile of the

two-dimensional Fourier transform of the object at the same angle (Figure 11a) [27]. If all of the acquired

slices undergo the Fourier transform to be interpolated into a two-dimensional Fourier plane, the object

can be reconstructed by taking the inverse Fourier transform [27]. In the spatial domain shown in Figure

11b, each view can be found by integrating the image at a particular angle [26].

Figure 11(a): In the frequency domain, the one-dimensional view at a particular angle is the same as the two-dimensional

Fourier transform profile of the image spectrum [27] (b) The spectrum of each view can be integrated at a particular angle that

the original slice was acquired in the spatial domain [26]

The second method, filtered back-projection, is still popular in commercial MDCT scanners. Before the

application of the image reconstruction algorithm, pre-processing steps, including compensation for the

use of polychromatic x-rays and multi-detectors, must be performed [26]. In back-projection, all the

image pixels for each acquired image are “smeared” back along the ray to the same value in the direction

it was originally acquired [26]. The final image is the sum of all the back-projected views. However,

back-projected images are very blurry because the bright pixels are “smeared” across the entire image

rather than putting them in the exact position as shown in Figure 12a [26]. This results from the circularly

symmetric nature of the point spread function used in back-projection [26]. Filtered back-projection is

Page 34: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

13

used to counter the blurriness. A high-pass filter, or a sharpening filter is used to detect sharp edges within

the projection while ignoring the flat areas [26]. The filter, as shown in Figure 12b, creates a uniform

signal in the peaks, and introduce negative spikes by the peak to counteract the blurriness [26]. However,

the filters also accentuates the noise in the image since noise presents as jagged edges. The trade-off

between the level of noise and the accuracy of the image needs to be considered for each clinical

application.

Figure 12 (a): Back-projection schematic that shows the reconstruction of a single bright spot. The "smearing back" of the image

spectrum causes blurriness. (b) Filtered back-projection of the same image with a single bright spot. The negative spikes beside

the peak and the uniform signal of the peak help to counteract the blurriness

Image reconstruction techniques can also have influence on radiation dose efficiency. Methods such as

iterative reconstruction, which will be discussed in Section 2.6.2, can reduce dose. However, research and

development has not been focused on improvements in image reconstruction algorithms because the gain

in image quality in moving away from filtered back-projection techniques is minimal [28]. This has

resulted in little motivation for manufacturers to expend resources on this subject matter. As such, the

most common image reconstruction technique in modern MDCT scanners remain filtered back-projection

[28].

2.3 Ionizing Radiation and Cancer Risk

X-rays are a form of electromagnetic radiation that have wavelengths ranging from 0.01- 10 nm. When

the photons are sent through the body, they can interact with the individual atoms in the tissues. The

photon’s energy is absorbed by the orbiting electron. The energetic electron is eventually released, and

these high-energy electrons can ionize numerous molecules in the tissues by direct collisions with their

electrons as they traverse through the cell [29]. X-ray technologies, such as computed tomography,

exploit the different extent to which energy-transfer processes occur in different materials. Linear

attenuation coefficients, which vary based on the material, are used as a measure of the probability of x-

Page 35: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

14

ray interaction per unit thickness [30]. The different degrees of interaction between the x-rays and the

penetrated materials as shown in Figure 13 in the body are responsible for the contrast in CT images.

Figure 13: Linear attenuation co-efficient for absorbing mediums in the body [30]

Ionizing radiation’s effect on molecular and cellular responses have been studied extensively in literature.

Radiation can induce chromosome aberration. The lesions in the chromosomes can reconstitute without

morphological changes, rejoin incorrectly with another break close in time and space to produce intra- or

inter-chromosomal aberrations or remain open to cause a simple break in the chromosome during mitosis

[31]. Ionizing radiation can also induce potentially mutagenic lesions in the DNA, which includes small

and large deletions or point mutations in single genes [32]. It is hypothesized that radiation can cause up

to a twentyfold change in induced mutation frequencies in autosomal genes [32]. Since DNA deletion is

the most common mutagenic response after exposure to ionizing radiation, it is unlikely that the normal

DNA check and repair during DNA replication process will cause a recovery in cells. Furthermore, gene

amplification often results from the process of DNA repair [33]. Gene or chromosomal mutations

involved in cancer development are hypothesize to arise indirectly as a consequence of persistent genomic

instability caused by the radiation exposure [29].

The relationship for prediction of dose-response and time-dose effects for radiation induced cancer is

described in Equation 1[29].

𝐸 = 𝛼𝐷 + 𝛽𝐷2 (1)

The health effect (i.e. chromosomal aberrations, gene mutations, radiation induced cancers etc.) from

radiation dose exposure (D) is a function of α, a single-hit intratrack component, and β, two-hit intertrack

component[29]. Single hit intratrack components are described by single dose exposure events while

Page 36: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

15

intertrack components can be described as lethal doses or accumulated doses [29]. As described

previously, the most accepted quantitative model for low dose radiation induced cancer is from The Life

Span Study that consists of about 120 000 survivors of the atomic bombings in Hiroshima and Nagasaki

Japan, which estimates a 1 in 100 chance of developing cancer at an exposure of 100 mSv [29]. The study

follows the cohort over a period of 50 years from 1950-2000 and includes both sexes and all ages at

exposure [29]. The large variety of exposure levels and the ease of tracking due to the Japanese family

registration system has made the Life Span Study cohort an important source of data for quantitative

estimates of risk from ionizing radiation exposure [29]. The risk estimates for cancer incidence and

mortality from radiation exposure varies in accordance with the averages dose, radiation source (i.e. x-

rays, external etc.) and the radio-sensitivity of the tissue (i.e. breast, stomach, thyroid etc.) [29].

2.4 Radiation Dose Output Measurement Metrics

Due to the different parameters that can affect radiation dose, reference standards are required to

communicate and compare radiation dose output for different platforms on CT. Basic dose reports

generated for CT studies will likely have measured values for CT dose index, volume CT dose index,

dose-length product and effective dose.

2.4.1 CT Dose Index (CTDI)

The CT Dose Index was introduced in 1981 to standardize the metric that is used to quantify radiation

output from a CT examination [34]. This method uses a standardized phantom to gauge the radiation dose

output of a CT scanner [8]. Cylindrical phantoms that are 14-15 cm in length composed of a

polymethylmethacrylate (PMMA) material are to be used for CTDI measurements [34]. For body

examinations, the standard cylindrical phantom should be 32-cm in diameter, whereas the head phantom

is 16-cm in diameter [34]. Standardized phantoms have allowed for increased accuracy as it takes into

account the scattered radiation at the ends of the fan beam [34]. To measure the CTDI, a long ionization

chamber integrates the primary and scattered radiation in a single scan, and normalizes it to the nominal

beam width [34]. This method accurately detects a[34] higher estimated radiation dose if the fan beam is

comparatively wider than another scan that used a narrower beam . Criticisms of the CTDI has focused on

the insufficient length of 100 mm long pencil ionization chamber used to collect the dose, and the

insufficient length of the cylindrical phantom to accurately represent a typical-sized patient [34].

However, it is important to remember that the purpose of CTDI is to quantify the radiation output of a CT

system rather than estimate the patient dose [34].

Page 37: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

16

2.4.2 Volume CT Dose Index (CTDIvol)

The CTDIvol was conceptualized to more accurately represent dose for a specific scan protocol by taking

into account any gaps or overlaps between the radiation dose profiles in helical CT scans [35], [36].

CTDIvol approximates the average dose in measured in the standard phantom during a helical scan that

cover the entire length of the phantom [37]. This metric provides a standardized measurement that can be

compared across different scan protocols or scanners [34]. The CTDIvol, measured in units of milliGray

(mGy) is defined as the weighted CT dose index (CTDIw) divided by the pitch [35], as shown in equation

(2).

𝐶𝑇𝐷𝐼𝑣𝑜𝑙 = 𝐶𝑇𝐷𝐼𝑊

𝑝𝑖𝑡𝑐ℎ=

1

3𝐶𝑇𝐷𝐼100,𝑐𝑒𝑛𝑡𝑒𝑟 +

2

3𝐶𝑇𝐷𝐼100,𝑝𝑒𝑟𝑖𝑝ℎ𝑒𝑟𝑦

𝑝𝑖𝑡𝑐ℎ (2)

The pitch is defined as the ratio of the distance that the patient table travels per rotation to the nominal

beam width [35]. The CTDI100 is a standardized metric derived from the integration of the radiation dose

profile from a single axial scan over specific integration limits using a 100-mm-long, 3 cm3 CT pencil

ionization chamber and the two standard-sized cylindrical phantoms noted in Section 2.4.1 [35]. Similar

to CTDI, the CTDIvol does not equal the patient dose, but rather, CTDIvol simply presents a method to

compare doses delivered by various scan protocols [34]. The CTDIvol details how the machine was

operated, and so, the patient dose can be estimated with this metric providing that additional information

such as patient size and patient anatomy are available [34].

2.4.3 Dose Length Product (DLP)

DLP is the product of CTDIvol and the scan length, which presents the total amount of radiation that is

incident upon a patient [38]. This metric, measured in milliGray-centimeters (mGy-cm), accounts for the

amount of radiation output incident upon the patient, and the length of the scanned area covered in the CT

examination [37]. Similar to the CTDI and CTDIvol, the DLP is quantified using the standard-sized

cylindrical phantoms [38]. DLP measurements in dose reports will provide users with insight of any

overscan that may have occurred during a CT examination [39].

2.4.4 Effective Dose (E)

Effective dose is designed for population-based dosimetry, and radiation protection because it considers

the stochastic risk associated with the exposure to ionizing radiation [6]. In the definition by the

International Commission for Radiological Protection (ICRP), effective dose, measured in milisieverts

(mSv), is the “weighted sum of the equivalent doses in all tissues in the body, where the equivalent dose

for an organ represents the sum of the absorbed dose averaged over a tissue or organ weighted by the

Page 38: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

17

radiation weighting factor” [40]. For x-ray photons, the radiation weighting factor is 1 [40]. This suggests

that a dose of 1 mSv poses the same risk to a patient regardless of the radiation source or anatomy being

exposed [6]. Traditionally, the European Commission or ICRP have published conversion factors for

different regions of the body using Monte Carlo dose simulation tools [40]. However, these published

conversion factors were computed using single-slice scanners and did not take into account scanning

voltages, specific sex tissues, age, or variation in body size and shape [40]. It is, therefore, important to

consider the known exponential relationship between patient size and absorbed dose to estimate patient

size-specific dose estimates from scanner output values [34].

2.5 Technological Methods for Dose Optimization

As CT delivers some of the highest radiation doses in diagnostic radiology, there is increasingly large

incentive for CT vendors and third party companies to develop dose saving technologies that are both

easy-to-implement and effective. Consumers have shifted their priority for CT scanners that produce the

highest image quality to wanting a balance between radiation dose and diagnostically relevant images.

This drive has resulted in the development of imaging techniques, built-in technologies from CT vendors

and dose-saving technologies that are designed by third-party companies as described in this section.

2.5.1 Effects of Technical Parameters on Radiation Dose

The most basic method to ensure that radiation dose follows the ALARA approach is to take into account

the specific patient attenuation (i.e. patient thickness and height) and diagnostic task [36]. This can be

achieved on all modern CT platforms by optimizing the four adjustable parameters that contribute most

significantly to radiation dose (i.e. tube current, peak kilovoltage, pitch, gantry cycle time) [41]. The

parameters and their effects on radiation dose are described in Table 1. The parameters exist in tightly

integrated relationships, which suggest that achieving a delicate balance of these parameters is often

difficult and time-consuming.

Table 1: A summary of technical parameters that may affect radiation dose in CT examinations

Parameter Description Dose Optimization Strategy

Tube Current (mA) -Amount of ionizing radiation delivered by the x-ray tube [42]

-Varies between scanner models (i.e. different mAs are used to achieve same dose) [43]

-Should be adjusted to patient thickness because attenuation changes according to amount of adipose tissue [44]

- Use technique charts (i.e. guidelines for mAs selection as a function of patient size) [44]

-↑ tube current= ↑ image quality=↓ noise [45]

Tube Voltage (kV) -The energy of the delivered photons [42] -Changes in tube voltage influences tube current [8]

-Radiation dose increases with the square of

Page 39: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

18

tube voltage [7], [13]

Gantry Cycle Time -The speed at which the CT scanner rotates around the patient (i.e. speed at which the images are obtained) [42]

-Gantry cycle time are now in sub-second range for all operational CT scanners [46]

-Positive linear relation with radiation dose, if all other factors are held constant [41]

Pitch -Detector pitch is used in single slice CT, and is defined as table distance travelled in one gantry rotation divided by beam collimation [47]

-When detector pitch equals 1, x-ray beams are contiguous for adjacent rotations [47]

-Beam pitch is used in MDCT, and it is defined as table distance travelled in gantry rotation by total thickness of all simultaneously acquired slices [47]

- Negative linear relation to radiation dose [42]

-↑ pitch= ↓ radiation dose= ↓ image quality [42], [47]

Specific attention should be paid to the possibility of image quality improvement while simultaneously

reducing radiation dose by using lower tube potentials in CT exams involving iodine-contrast media. The

underlying principle is that the attenuation coefficient of iodine increases as photon energy decreases

toward the k-edge energy of 33 keV [44]. In clinical applications where iodinated-contrast media is used,

hidden pathologies become more contrasted because of the differential distribution of iodine [48].

However, increased noise levels tend to appear in images with lower tube potentials due to the increased

absorption of low-energy photons by the patient [44]. Clinical studies have shown that reduced tube

potentials in abdominal CT does not significantly sacrifice low-contrast detectability when the patient

weight is below 80 kg [49]. Furthermore, hypervascular liver tumours were detectable with a 23% lower

radiation dose, and a decrease in tube potential from 120 kV to 100 kV [50]. McCollough et al. warns that

the patient size needs to be below a threshold in order for better image quality to be generated at a lower

tube potential [44]. Consequently, it is important to optimize tube potential for a specific patient size and

diagnostic task [44].

2.5.2 Built-in Technologies for CT Scanners

All of the CT scanners employed in Ontario are required to have dose display on the console, whether it is

in the form of DLP or CTDIvol [51]. The expected dose index is displayed before a study to act as a

checking mechanism to ensure that the selected scanning series will result in the range of expected doses.

The CT scanners used in Ontario are also required to have automatic exposure control capabilities [52].

Below is a summary of a non-exhaustive selection of literature that discuss dose optimization

Page 40: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

19

technologies available natively on most CT platforms. Typical dose savings are provided, but dose

reduction is dependent upon patient size and scan type.

1. Automatic exposure Control/ Automatic tube current modulation (Applicable for all scan

types, dose reduction of 50-70% [43])- Automatic tube current modulation allows users to set a

noise threshold for the final image so that tube current can be adjusted to maintain the selected

noise level, and image quality while reducing tube loading and minimizing streak artifacts [53].

Attenuation increases as patient thickness increases, and so, tube current needs to be increased for

areas where patients are thicker [52]. There are two types of modulation that are commonly used -

in MDCT. Angular modulation adjusts tube current for each projection angle to the attenuation of

the patient to minimize x-rays in projection angles [53]. Z-axis modulation determines the tube

current using the patient’s localizer radiograph projection data and a set of empirically determined

noise prediction coefficients to adjust tube current accordingly [53]. The patient’s attenuation data

is predicted using the patient density and patient size as recorded by the radiographer. Modern CT

systems allow for near real-time adjustment of the tube current using a feedback mechanism by

incorporating pre-programming and a feedback loop [44].

2. X-ray overbeam elimination (Applicable to all scan types, and 20-40% dose reduction [43])-

Overbeaming, as defined by the ICRP, describes the situation when the x-ray beam extends

beyond the active detector area, and does not contribute to the formation of the image [54]. This

situation is most serious when the total beam width is small, and so, wider beam collimations in

MDCT generally results in more dose efficient examinations [54]. A common method to

minimize x-ray overbeaming is pre-patient control of x-ray tube focal spot, and beam collimation

[21], [54]. This method continually detects beam position to ensure that the beam is stabilized on

the detector by re-positioning collimating aperture if required [21], [54].

3. Axial cardiac scanning (applicable for cardiac scans, and 68-79% reduction [55])- Axial

scanning, otherwise known as “sequential scan mode” has been introduced as an alternative

scanning technique to standard helical scanning in coronary computed tomography angiography

scans [43]. Radiation is reduced in axial scanning because radiation is only applied at a pre-

defined point in the cardiac cycle whereas traditional helical scanning applies radiation during the

entire cardiac cycle [56]. A randomized trial by Hausleiter et al. showed that image quality from

axial cardiac scanning is not inferior to helical scanning, but is able to reduce radiation exposure

by 69% [56]. However, axial cardiac scanning does not provide dynamic information and requires

a stable heart rhythm of below 65 beats per minute [43], [56]. Axial cardiac scanning should be

considered for patients to avoid high radiation exposure.

4. Prospective electrocardiogram (ECG) Gating (Applicable to cardiac scans, and 23-38%

reduction [55])- This method uses forward prediction of R-wave timing and sequential scan mode

as opposed to the standard retrospective ECG gating that uses backward looking measurement of

Page 41: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

20

R-wave timing and helical scanning [57]. Prospective ECH gating effectively lowers radiation

dose because radiation is only turned on during the diastolic phase, whereas standard

retrospective ECG gating uses radiation for the entire R-R interval [55], [57]. A clinical study by

Shuman et al. showed that similar image quality is achieved using both methods [57]. However,

prospective ECG gating is limited by the lack of available dynamic information and its

recommendation for a heart rhythm of below 75 beats per minute. Similar to axial cardiac

scanning, prospective ECG gating should be considered in clinical studies where low radiation

dose is important for the patient [57].

2.5.3 Dose Saving Technologies for All CT Platforms

It was not until recently that radiation dose has become a greater concern, so some older CT platforms

may not contain the newly developed built-in dose optimization technologies. This provides a worthwhile

business opportunity for third party companies who are not CT vendors to develop dose-saving

technologies that can be adopted by any CT platform. Some common technologies are described:

1. X-ray Filters (Applicable for all scan types, and 17-25% dose reduction [58])- X-ray filters are

used to decrease the “soft x-rays” that are absorbed by the patient that never reach the detectors,

and do not contribute to the image [21]. These aluminum filters can be bow-tie shaped, beam-

shaping or flat, but flat filters are comparatively less efficient at reducing surface radiation dose

[21]. Bow-tie and beam-shaping filters minimize exposure in the thinner portions of patient

anatomy [21]. Itoh et al. designed a new filter to be used in lung cancer screening that was able to

reduce absorbed doses by 17% and improve noise levels by 9% [58].

2. Iterative reconstruction (Applicable for all scan types, and 50-60% dose reduction [43])-

Iterative reconstruction algorithms gained notice in CT scans because it incorporates the data

acquisition process such as noise, beam hardening or scatter into the image reconstruction process

[48]. Its consideration for the data acquisition process, and its use of more accurate noise models

that are based on photon statistics allow for lower image noise compared to traditional filtered

back-projection [44], [48]. Furthermore, iterative reconstruction has improved spatial resolution

and reduced image artifacts. Its handling of non-ideal data or incomplete data sets is superior to

traditional methods, which allows for radiation dose reduction because less projection views are

required to obtain the same image quality [48]. Despite its lower noise levels, the appearance of

iteratively reconstructed images is different from the traditional filtered back-projected images

[48], and so, users will likely require training and time before fully adjusting to the iterative

reconstructed imaged. Additional limitations include the long reconstruction times [48], and high

expenses to upgrade (approximately $ 200,000) to this new reconstruction system [43].

3. Dose monitoring systems (applicable for all scan types)- Dose monitoring systems are designed

to collect dose data from an institution’s scanners and provide a platform for dose data analysis

[8]. These systems can automatically transmit to dose registries that are set up in the jurisdiction,

Page 42: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

21

such as the American College of Radiology’s dose registry that compares the doses across

facilities for similar scan types [8]. Institutionally, these systems are able to provide a means of

identifying unusually low and high doses, track individual patient doses and analyze the effects of

different parameters such as patient size on dose [8]. Furthermore, the system provides an

effective platform audit the collected data for trends [8]. These trends are an asset for the

monitoring and review of standard clinical protocols, which should be an indicator in quality

assurance plans.

4. Organ shields (Specific organs depending on shield type, 60-90% dose reduction to anatomy

being shielded outside scanning area [43],[59] and 40-67% dose reduction for anatomy being

shielded inside scanning area [44], [60])- Shields designed for organs outside of the scanning

area will have no effect on the image quality [43]. These shields are designed to reduce radiation

dose that may be incident on the patient caused by scatter [43]. Shields that are used inside the

scanning area are designed to protect radiosensitive tissues and organs, such as the eye lens,

thyroid, or breasts [43]. These shields are normally made of thin flexile sheets of latex saturated

with bismuth [44]. The overall dose remains unchanged, but there are dose savings for the

shielded organ [43]. However, these shield often result in noisier images and lower overall image

quality [43], [44]

2.5.4 Limitations of Dose Saving Technologies

Although dose optimization technologies are effective in minimizing radiation dose, they are often very

costly or difficult to employ. The many choices that accompany these technologies may also lead to an

information overload, which may cause workflow problems as radiology teams must adapt to these

technological changes [61]. Another disadvantage that arises from the application of some technologies is

the longer processing time. Newly developed iterative reconstruction algorithm such as new iterative

reconstruction algorithms can reduce the noise of images and lower the required radiation dose, but the

computational time for these images are increased [48]. Dose optimization technologies also need to be

used in accordance to the specifications of the manufacturers and the CT vendor. For example, some CT

platforms do not encourage the use of bismuth organ shields because the automatic exposure system

readjusts the tube current in response to the detection of the bismuth shield, which counters its intended

benefit [62].

The application of technologies is useful to start the dose optimization process. However, one of the

primary barriers to implementing effective dose optimization is obtaining radiologist acceptance and

subsequently, a culture change [14]. Radiologists may often reject dose optimization efforts because they

do not believe in the risks of CT radiation or do not like the changes in image quality [14]. A successful

Page 43: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

22

dose optimization model requires commitment from jurisdictions and/or institutions to prioritize

optimization. This commitment must reach all levels of healthcare as CT usage can be significantly

reduced if CT diagnostics is only ordered and performed when justified by clinical indication [63].

Alternative imaging techniques that do not have known biological effects such as magnetic resonance

imaging and ultrasound should be used when equal or greater diagnostic information can be obtained

[63].

2.6 Radiation Dose Optimization Strategies

It is important to recognize that dose optimization is not synonymous with dose reduction. Significantly

low doses may yield diagnostically inadequate images that result in repeated scans, which defeats the

purpose of lowering radiation dose. Thus, the benefit-risk ratio of CT examinations must be maximized

through dose optimization. A comprehensive guideline, protocol or legislation is often used for quality

improvement and cost control [64]. However, many protocols and guidelines are often recommended

based upon lacking, misleading or misinterpreted scientific evidence that has not been evaluated in the

appropriate settings [64]. Dose optimization strategies should adopt research evidence into health-care

decision making that takes into account the needs of various stakeholders including the patients,

organizations, and healthcare professionals [65].

2.6.1 History of Jurisdictional Dose Optimization Regulations

From it conception in 1971 until 2000, medical incidents as a result of CT scanner malfunction or user

error were unheard of. There was little awareness for radiation dose optimization for CT examinations

during this period, even though the International Commission for Radiological Protection (ICRP) foresaw

the complications that may arise from increased reliance on CT scanners [66]. The European Atomic

Energy Community (Euratom) conceptualized its own Directive 97/43/Euratom for the use of ionizing

radiation in medical exposures in 1997 in accordance with the recommendations from the ICRP. Many

countries in Europe, as members of the Euratom, were required to transpose the Directive into legislated

regulations. In fact, Euratom took legal action against those member states for non-transposition of the

Directive [67]. Member states, by association with Euratom, should have some type of legal framework in

place for the use of ionizing radiation in medical exposures by 2002, which is the year the Directive

entered into force [68].

Public awareness of radiological protection of CT scans first appeared in North America when a peer-

reviewed article published in the American Journal of Roentgenology in 2001 revealed that some U.S.

hospitals used adult scanning protocols for paediatric scans, which increases the risk of cancers in

children [66]. This publicized relationship between CT examinations and cancer risk attracted the

Page 44: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

23

attention of the media, which helped to shift the focus of the CT manufacturers from image quality

improvement to include radiation dose management [66]. Furthermore, it encouraged the formation of

proper imaging guidelines such as Image Gently and Image Wisely [66]. However, the regulatory

organizations did not take notice of these radiation risks until 2009 when the Cedars-Sinai Medical Center

in California disclosed that it had administered eight times the normal radiation dose to 206 possible

stroke victims over a 18-month period in an attempt to improve image quality [15]. This incident reached

the Ministry of Health decision-makers in many states, and different state legislations, such as California

Senate Bill 1237 and Section Code 289.227 in the Texas Department of Health Services regulations, were

established.

Despite the radiation risks, the demand for this modality continues to increase. Surveys by The

Organization for Economic Cooperation and Development (OECD) have revealed that the average

number of CT exams per 1000 population in OECD countries rose from 110.7 in 2007 [69] to 131.8 in

2011 [70]. Moreover, there is growing penetration of CT scanners among developing countries. Ongoing

surveys by the World Health Organization have shown that low-income countries prefer to deploy their

health expenditure on CT scanners over other imaging modalities [71]. For example, Niger has 3

operational CT scanners and no magnetic resonance imaging devices [71]. As CT scanners penetrate into

the developing world, the radiological community in developing countries have also increased awareness

for radiological protection of CT examinations and different campaigns, such as AFROSAFE, are looking

to develop dose optimization initiatives.

2.6.2 Legislation

Legislation is a body of rules of binding legal force and effect, prescribed, recognized and enforced by a

controlling authority. When a legislation regulation is broken, the party is subject to criminal punishment

or civil liability. In an international organization such as the European Commission, there are three basic

types of legislation including regulations, directives and decisions. Regulations are laws that are

applicable to all European Union countries, while Directives set out a framework that needs to be

transposed into the national law by each country and a decision only deals with a particular issue or

specific persons [72]. There are three types of legislation- statutes, regulations and bylaws. Statutes are

broad, governing principles or rules that are publicly debated by the governing body and voted upon

before coming into regulation, whereas ordinances and bylaws are the details of operation and

implementation that support the statute [73]. Radiation protection legislation in countries can either be

generally applicable for all ionizing radiation sources (e.g. industrial radiation, background radiation,

medical radiation), or specific to the application of ionizing radiation in medical exposures. These legal

Page 45: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

24

acts will provide general standards for the operational life cycle (i.e. installation, operations and

decommissioning) of a CT scanner.

2.6.3 Supplemental Documents

Supplemental documents to legislation are designed to optimize the implementation of legislation by

providing guidance for specific circumstances. In radiation protection for medical exposures, these

documents are usually written by organizations that have a vested interest in ensuring safety for patients

and workers, including the professional colleges for radiology staff, and multi-disciplinary forums for

radiological safety (e.g. International Atomic Energy Agency, Eurosafe). Supplemental documents can

range from clinical practice guidelines by medical authorities to basic safety standards from licensing

bodies. These documents are usually not legally binding, but they do provide “best practice” insight into

the care options available for medically exposing patients to ionizing radiation.

2.6.4 Institutional Dose Optimization Strategies

Evidence-based decision making and research utilization should always be incorporated into the design of

a comprehensive dose optimization strategy. Jurisdictions often recognize the importance of medical

exposure radiation protection, but human and financial resources are often obstacles to establishing a

sustainable regulatory framework. In response to the lack of jurisdictional regulations, many academic

centres have designed programmes that attempt to ensure dose optimization at an institutional level. Table

2 summarizes a non-exhaustive selection of literature that discuss dose saving strategies that have

successfully been undertaken at an institutional level.

Table 2: A non-exhaustive selection of institutional strategies that have been implemented in an attempt to optimize radiation

exposure from CT examinations

Policy Name Institution Description

Stepwise

implementation of

changes in CT scan

protocols

Mayo Clinic Arizona

and Massachusetts

General hospital

-Start with small changes, then medium changes before

proceeding to large changes [14]

-Small changes: reduce number of examinations, reduce

scanning phases, reduce scanning coverage [14]

-Medium changes: reducing tube current and peak kilovoltage

[14]

-Large changes: implementing de-noising and iterative

reconstruction techniques [14]

Weekly Dose

Reports

Massachusetts General

Hospital

-A study that was performed on the Department of Radiology

and Division of Cardiology [74]

-Tracked the mean effective dose for patients who were

undergoing cardiac computed tomography angiography (cCTA)

Page 46: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

25

[74]

-Pre-intervention and control groups did not received weekly

dose reports [74]

-Post-intervention groups received weekly dose reports that

included information on the number of gated cardiac exams

performed and the mean radiation dose and range of each

exam type [74]

Continuous

Monitoring of CT

Dose Indexes

Dubai Hospital -Recording of patient radiation dose indexes from 2008-2012

for three types of routine scans: head, chest, and abdomen and

pelvis [75]

-Monitored the change in average DLP on a monthly basis and

average third quartile DLP annually [75]

-Adopted dose-saving strategies (e.g. lower tube potential,

reducing scan length) as image quality was monitored [75]

-Reached DLP levels that were comparable to the diagnostic

reference levels reported by European countries [75]

2.7 Current Regulatory Framework for CT Standards in Ontario

In 2008, Health Canada published Safety Code 35: Safety Procedures for the Installation, Use and

Control of X-ray Equipment in Large Medical Radiological Facilities to “provide specific guidance to

large medical radiological facilities where diagnostic and interventional radiological procedures are

routinely performed using radiographic, radioscopic or computed tomography equipment [76].” The

safety code clearly dictates that the details are primarily for the instruction and guidance of persons

employed in Federal Public Service departments and agencies [76]. This does not include facilities that

are under provincial or territorial jurisdiction, which are subjected to their own provincial or territorial

statutes [76]. Although it is not mandatory to adopt the clauses in the Safety Code, some provincial and

territorial jurisdictions have opted to incorporate individual sections into the accreditation guidelines or to

make references to the Safety Code in provincial radiation protection resources. However, the Ministry of

Health in Ontario has decided to not implement the Safety Code’s recommendations.

It was not until May 2011 that there was official legislation for CT usage in Ontario. This official

regulation was incorporated as an amendment to Regulation 543 X-ray Safety Code under the Healing

Arts Radiation Protection Act (HARP Act). Before the amendment the regulations, the x-ray safety code

failed to define CT scanners as a class of x-ray machine and so, CT operation and prescription were not

regulated. Through the amendment, the Ministry of Health and Long-Term Care was able to present

specific regulations that pertain to CT scanners only:

Page 47: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

26

Define CT scanners and dental scanners [77]

Limit the types of health professionals (i.e. physicians and oral and maxillofacial surgeons) who

may prescribe CT scans [77]

Limit the types of health professionals (i.e. Oral and Maxillofacial Radiologists and Dentists who

are qualified by the Royal College of Dental Surgeons of Ontario’s Standard of Practice) who

may prescribe dental CT scans and operate dental CT scanners in a dental facility [77]

Limit the health professionals (i.e. Physicians and Medical Radiation Technologists) that are

authorized to operate CT scanners [77]

Additionally, the inclusion of CT scanners in the original act allows for more specific instructions on the

installation of the CT scanner with descriptions of the required barriers to the CT scanner room. The act

also limits the radiation exposure to the health care personnel by defining upper threshold limits of a

whole body dose equivalent of 1 mSv per week for x-ray equipment operators [78]. Radiation protection

officers that are responsible for the testing and safe operation of x-ray machines are now also responsible

for the safe operation of CT scanners [78]. Despite the inclusion of CT scanners in HARP Act, many of

the original clauses are outdated and fail to apply to the operations of a CT scanner. Furthermore, the

clauses are vague in its application to CT scanners and thus, the problem of CT radiation dose is not

addressed. The recommended approach to radiation protection in Ontario is the ALARA principle as

suggested by the International Commission on Radiological Protection. However, the ALARA approach

is simply a precautionary principle that is vague and in need of additional decision rules to strengthen its

specific application to CT radiation dose.

Although there is no specific regulated legislation for CT usage in Ontario, there are more precise clinical

guidelines and standards available through the College of Physicians and Surgeons of Ontario. The

Clinical Practice Parameters and Facility Standards was last revised in April 2010 [52]. The document

extracts the key highlights from research reports by the Healthcare Human Factors Group, Food and Drug

Administration from the United States and the Canadian Association of Radiologists [52]. It addresses the

role of each healthcare professional that is needed to staff a facility, the design of the facility housing the

CT scanner, the equipment standards for an operational CT scanner, quality control issues, and the

development of procedures to maintain patient safety [52]. This document is more detailed than the

HARP Act but it fails to make specific recommendations regarding the safe range of radiation doses for

Page 48: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

27

each common scan type. Unlike the provincially legislated HARP Act, the College’s clinical guidelines

are synthesized based on large bodies of evidence, information and professional opinion whose purpose is

to help improve the quality and consistency of care in clinical situations and thus, guidelines are only

recommendations and do not have the force of law [1]. There is the opportunity for a provincially

enforced legislation that ensures CT scanners are operated in accordance with the ALARA principle.

Page 49: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

28

Bayer Inc., Mississauga, Canada

3 Study Design

Due to the cancellation of funding, the study design has had to be altered to align with the diminished

available resources, while still achieving the overall goal of guiding policymakers in Ontario on how to

minimize patient radiation exposure through a stronger regulatory framework. This section briefly

describes the original study design to explain the elements that were translatable and maintained for the

final study design. Additionally, the rationale for the final study design will be discussed.

3.1 Original Study Plan

The original study plan was divided into three phases that together can provide a high-level overview of

the enablers, and barriers to dose management at the institutional level. Phase 1 aimed to perform a

comparative analysis of longitudinal dose data collected from eXposureTM dose monitoring software by

Bayer HealthCare* (hereafter referred to as ‘Bayer’). The dose data from Ontario institutions were to be

compared with institutions from other jurisdictions on typical CT scans to evaluate the impact of

regulatory or legislative factors on user engagement with the software, and the overall dose trends. The

significance of the dose monitoring software is its ability to provide uniformly treated data for

comparison. Dose trends were to be statistically analyzed and correlated with regulatory factors and user

engagement levels to determine what factors are predictive of an awareness for dose optimization and

standardization. Phase 2 aimed to extract regulatory and legislative factors via rapid literature review of

the radiation protection policies undertaken by the jurisdictions. These factors were to be analyzed using

an assessment instrument that was to be specifically designed to evaluate the medical exposure radiation

protection efforts undertaken by the jurisdictions. The preliminary results of Phase 2 were incorporable

into the final study plan. Phase 3 involved qualitative research, in the form of expert interviews. These

interviews are translatable to the final study plan as it is important to understand the needs, priorities and

concerns of each CT stakeholder group when designing effective and implementable regulations. The

results of each phase in the study were to contribute towards formulating a comprehensive and

implementable model for radiation protection of CT scanners in Ontario.

3.2 Final Study Plan

A change in the study design was required due to the cancellation of funding, which impacted the timeline

and resources for the project. The elimination of Phase 1 of the original study plan required the new study

design to have a different means of comparing the relative effectiveness of various regulatory and

legislative factors on dose optimization methods. In the final study design, an expanded selection of

jurisdictions was selected for analyses of different regulatory approaches to radiation protection in

medical applications. Expert interviews with representatives from each jurisdiction provided insight into

Page 50: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

29

their experiences with implementing dose optimization regulations within a jurisdiction, and allowed for

recurring facilitators and barriers to dose optimization efforts to be identified. An assessment framework,

as described in Phase 2 of the original study plan, was also designed in the final study plan. This

framework provided a systematic method to assess and compare jurisdictional policies that have been

developed to optimize CT radiation dose. A high-level overview of the relationship between the

assessment results and the regulatory approaches helped to highlight the elements that improve

implementation of dose optimization strategies. Qualitative interviews, denoted as Phase 3 previously,

identified the factors that should be considered when designing a regulatory framework. Based on the

results and analysis of each aspect in the study design, elements that allowed for successful design and

implementation of a radiation protection framework in medical exposures were elicited. These elements

were then incorporated into the comprehensive model that was designed to guide policymakers in Ontario

on how to effectively encourage prioritization of radiation dose management at the institutional level

.

Page 51: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

30

4 Comprehension of the Jurisdictional Regulatory

Frameworks

The first specific objective was to select a variety of jurisdictional models designed to regulate CT

radiation dose exposure to patients. Selected models accounted for the widest range of approaches based

on current knowledge. Qualitative interviews with jurisdictional representatives provided a thorough

understanding of each jurisdictional model. Qualitative analyses of the interviews and review of the

radiation protection publications from each jurisdiction identified regulatory and legislative factors that

may facilitate the implementation of radiation dose optimization regulations.

4.1 Selection Criteria

The selection process for the jurisdictions that were included in the study can be divided into two phases.

The preliminary selection included six jurisdictions, with each jurisdiction having available data on

eXposureTM. The second phase of jurisdiction selection focused on expanding the selection to provide a

more comprehensive perspective into the different possible approaches to radiation dose regulation.

4.1.1 Preliminary Selection

Preliminary selection of jurisdictions was limited by those jurisdictions that have institutions with

eXposureTM dose tracking system installations. A selection criteria was applied to shortlist those

jurisdictions that will be most useful to the overall objective of the research project, as follows:

1. There must be both academic and community institutions that have implemented the eXposure

system within the jurisdiction

a. An “academic institution” is defined as one that retains residents or trainees on staff when

administering CT dose; these staff may be residents in radiology or post-graduate

students in medical physics or engineering.

2. The radiation protection policy has been updated in recent years to include medical exposure to

ionizing radiation from CT diagnostics.

3. When two or more jurisdictions have similar radiation protection policies, priority will be given

to the jurisdiction that has more academic and community institutions available for data analysis.

Data extraction was to be performed by Bayer, who had committed limited time and resources to the

research collaboration. The number of jurisdictions that met the selection criteria was greater than Bayer’s

intended time and resource commitment. The inclusion of jurisdictions, therefore, was selected to

represent contrasting regulatory approaches as summarized in Table 3.

Page 52: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

31

Table 3: An overview of the jurisdictions that are available for data analysis on the eXposureTM software. A wide variety of

jurisdictional approaches were selected to provide a broad analysis in possible radiation dose management models, which will

allow for a strong evidence-based approach to Ontario radiation protection standards for medical exposures

Jurisdiction Meets

criteria?

Included in

preliminary

selection?

Justification for Inclusion or Exclusion

Ontario, Canada YES YES

Establishes a baseline for the recommendations

that will be needed to enhance the radiation

protection efforts

Currently, it uses an interesting human resources

strategy to promote the objective of quality

healthcare services delivered by quality health

professionals

British Columbia,

Canada YES YES

Provides a Canadian comparison to the Ontario

model

Interesting approach that provides the College of

Physicians and Surgeons of BC with authority that

is normally held by the Public Health Authority

Virginia, USA NO NO Data available only for an academic institution

New York, USA NO NO Data available only for an academic institution

Michigan. USA NO NO Data available only for an academic institution

Pennsylvania, USA NO NO Data available only for an academic institution

Texas, USA YES YES

High level role undertaken by Department of State

Health Services that liberates radiation dose

optimization responsibility to the institutional

level by mandating the establishment of radiation

protocol committees

California, USA YES YES A stringent approach that mandates the

accreditation of CT facilities and dose reporting

Ireland YES YES

A laissez-faire version of the DRL approach as

Ireland has not updated DRLs since 2004, but

encourages establishment of local thresholds

even though it is under the same Euratom

Directive as other European countries

United Kingdom

(including sites from

Scotland)

YES NO

Due to the limitation of the resources provided by

Bayer, we could only select two European

jurisdictions (i.e. those jurisdictions that are under

the radiation protection Euratom Directive)

Less IUs available for selection than other

European jurisdictions

Page 53: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

32

Germany YES YES

An intensive approach by the public health

authorities

Rigorous compilation of dose data annually to

manage DRLs for both adult and pediatric

populations

Switzerland NO NO Only academic institutions available for dose data

collection

4.1.2 Expanded Jurisdiction Selection

The selection of jurisdictions was limited by the available of dose data that have been published in peer

reviewed literature articles or officially published diagnostic reference levels. Available dose data were

required for a high-level comparative analysis of the regulative or legislative factors that are predictive of

successful radiation dose optimization regulatory approaches. Figure 14 describes the criteria that were

used to select the additional representative jurisdictions. Bolded jurisdictions represent those that were

already considered for analysis in the preliminary selection process because their dose data were available

on the eXposure software.

Page 54: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

33

1. Is the jurisdiction an Euratom Member?

2. Are radiation protection legislations in place?

3. Are there official diagnostic reference levels that were are regularly updated using

an evidence-based method?

4. Who is responsible for the DRL updates and/or QA and/

or accreditation?

Ireland: uses the recommended

thresholds set by the Euratom and has not updated them since

its initial establishment in 2004

Select ONE jurisdiction that does not have any official

DRLs despite integrating the

Euratom Directive 97/43 into its regulations

Germany: collects dose data annually

from all public institutions and updates DRLs

regularly

Switzerland: relatively less rigourous update of DRLs compared to

Germany, but still uses an evidence

approach to update DRLs

United Kingdom: radiation protection is entrusted into a non-governmental body that is under direct government control

Select ONE jurisdiction that is well-developed

economically

Select ONE jurisdiction that is still developing

economically

Select ONE jurisdiction that is well-developed

economically

Select ONE jurisdiction that is still developing

economically

NOYES

NO YES

Public governmental

health authority

Non-governmental

bodies

Figure 14: A flow diagram that shows the decision-making process for the expanded selection of jurisdictions. Bolded jurisdictions were already available in the preliminary selection process

because of available data on the eXposureTM system

Page 55: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

34

Jurisdictions were selected to include a wide range of regulation strength, comprehensiveness, geography,

healthcare system type and economic development, with the goal of enhancing the comparative analysis

of the jurisdictional approaches. Due to the time and resources limitations, consideration was also given

to the ease of understanding and interpretation of the jurisdiction’s radiation protection documents. For

example, jurisdictions with English as an official language were preferred when two countries with

analogous regulatory structures were considered. The expanded selection is summarized in Table 4, with

detailed justification of each additionally selected representative jurisdiction. The classification of the

regulation strength was determined by the series of questions posed in Figure 15.

Is there a general legislation for radiation protection of all ionizing

radiation sources, including a definition for medical exposures?

Weak Is there a specific radiation protection legislation for

medical exposures?

Weak

Are there compliance checks to ensure radiation protection

measures are incorporated at CT facilities?

Are there official DRLs that must be adhered to?

Moderate Moderate High High

NO

NO

NO NO

YES

YES

YES YES

Figure 15: Decision tree that helped to categorize the regulation strength of each jurisdiction

The economic development characterization was determined using the World Bank’s classification, which

updates each country’s categorization based on the gross national income (GNI) per capital from the

previous year [79]. The stratification of economies [79], based on World Bank’s definition for the fiscal

year of 2016, are as follows:

Low-income economy: GNI per capita <$1,045

Lower-middle income economy: GNI per capita is between $1,045-$4,125

Upper-middle income economy: GNI per capita is between $4,125-$12,735

High-income economy: GNI per capita >$12,735

Page 56: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

35

Table 4: A summary of the jurisdictions that were included from the expanded selection process. Jurisdictions were selected to

represent a wide range of regulation strength, geography, regulatory approach, economic development and healthcare system

type

Jurisdiction Characteristics of Jurisdiction Justification for Inclusion/ Unique Characteristics

Japan Regulation strength: weak Economic development: High-income Geographic location: Asia

Has highly privatized healthcare

An economically advantaged country with no existing radiation protection regulations

Australia Regulation strength: strong Economic development: High-income Geographic location: Oceania

Geographically far from other economically advanced countries and not under Euratom jurisdiction

Has radiation protection legislation and guidelines similar to Euratom standards

Kenya Regulation strength: Weak Economic development: lower-middle income Geographic location: Africa

Low income country with a radiation protection act that defines medical exposure

India Regulation strength: Weak Economic development: lower-middle Geographic location: Africa

Lower-middle income country with basic licensing standards for imaging modalities that use ionizing radiation

Portugal Regulation strength: Moderate Economic development: High-income Geographic location: Europe

A Euratom member state that does not have official DRLs or periodic inspections of CT facilities

Switzerland Regulation strength: Strong Economic development: High-income Geographic location: Europe

Not in preliminary selection because of similarity to Germany (only slight differences in the method to updating of DRLs)

A centralized, governmental driven approach to medical exposures radiation protection

United Kingdom

Regulation strength: Strong Economic development: High-income Geographic location: Europe

Not in preliminary selection because of similarity in DRL updates to other European countries and lower institution data availability

A centralized approach that uses a non-governmental organization to supervise and inspect radiation protection in institutions

4.2 Identification of Relevant Publications

To capture as many relevant regulatory documents as possible, a wide range of legal, governmental,

medical and scientific databases were searched. The search for publications should be extensive, and

therefore, no language restrictions were applied [80]. The flow of the literature search was as follows:

1. Review literature for official diagnostic reference levels and/or dose survey results from each

jurisdiction. Literature articles that provide a comparison of jurisdictional dose levels were

preferred because it is expected that these articles ensured comparability of the data collection

and analysis methods.

Page 57: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

36

2. Determine if the jurisdiction is under centralized regulatory standards from international

organizations that are focused on the use of nuclear energy, which has small sub-groups focusing

on radiation protection in medical applications.

3. Search for legislated radiation protection acts for medical applications from the governing

responsible authority.

a. If the jurisdiction does not have a medical exposure specific radiation protection act,

search for a general radiation protection act against ionizing radiation that mentions a

specific medical exposure clause.

4. Search for any supplemental documents that are designed to specifically address the use and

operation of CT scanners in the jurisdiction.

a. Quality assurance standards or clinical practice guidelines from an independent or

government appointed organization that conducts clinical audits.

b. Accreditation standards from a government recognized accrediting body.

The jurisdictional medical exposure radiation protection documents, whether legally binding or

recommended, were included for analyses. The inclusion of publications from international organizations

focused on radiation protection was limited to documents that have legal authority in the organization’s

member states. Table 5 provides a summary of documents that were reviewed for the analysis process.

For countries that do not have English as an official language, the relevant publications may not be

available for review. In these cases, Google Translator and another free on-line translator were used to

convert the foreign language into an English document. The use of two language translators minimizes

the discrepancies in the intended meaning of the written word. Due to the large number of documents

available on the scientific databases, the selection of documents was further streamlined by only including

documents that were recognized as playing an integral role in radiation protection of CT scanners by the

jurisdictional representatives that participated in the expert interviews (to be discussed in Section 4.3.1).

Table 5: A summary of relevant radiation protection publications for each jurisdiction that were included in the regulatory

approach analysis. Italicized documents were included in the preliminary assessment of jurisdictions using Regulatory

Assessment for Computed Tomography 1 (RACT 1), which will be discussed in Chapter 5. Documents highlighted in red font

were analyzed as legislative documents while documents highlighted in green font were considered supplemental in the

subsequent analyses. The dose articles that were highlighted in blue were considered official DRL levels in the subsequent dose

comparisons, while only a high level comparison was performed for the dose articles highlighted in orange.

Jurisdiction Relevant Radiation Protection Publications Diagnostic Reference Level or Dose Survey Articles

Australia 1. Australian Radiation Protection and Nuclear Safety Act 1998

2. Australia Radiation Protection and Nuclear Safety Agency’s (ARPANSA) Code of Practice for Radiation Protection in the Medical Applications of Ionizing Radiation

3. ARPANSA’s Safety Guide for Radiation

1. ARPANSA’s 2011-2013 National Diagnostic Reference Level Service Report

Page 58: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

37

Protection Diagnostic and Interventional Radiology

British Columbia,

Canada

1. College of Physicians and Surgeons of British Columbia’s Diagnostic Accreditation Program Standards for Global Imaging Modalities and Computed Tomography

1. Radiation Doses to Patients Receiving Computed Tomography Examinations in British Columbia (Aldrich et al.)

Canada 1. Health Canada Safety Code 35: Safety Procedures for the installation of X-ray Equipment in Large Medical Radiological Facilities

California, USA

1. Radiation Control Law— Health and Safety Code, Division 104: Environmental Health, Part 9: Radiation, Chapter 8

2. Joint Commission’s Diagnostic Imaging Standards

3. Intersocietal Accreditation Commission’s Standards and Guidelines for CT Accreditation

4. American College of Radiology’s CT Accreditation Program

1. Radiation Dose Associated with Common Computed Tomography Examinations and the Associated Lifetime Attributable Risk of Cancer (Smith-Bindman et al.)

Euratom 1. Council Directive 97/43/Euratom On health protection of individuals against the dangers of ionizing radiation in relation to medical exposure

2. Council Directive 2013/59/Euratom Laying down basic safety standards for protection against the dangers arising from exposure to ionizing radiation

Germany 1. Radiation Protection Ordinance on the protection against damage and injuries caused by ionizing radiation

1. Federal Office for Radiation Protection’s Notice for the updated diagnostic reference levels for diagnostic and interventional radiology (translated from German)

IAEA 1. Safety Standards Series: Radiological Protection for Medical Exposure to Ionizing Radiation (Safety Guide No. RS-G-1.5)

India 1. Atomic Energy (Radiation Protection) Rules, 2004

2. Institute of Nuclear Medicine and Allied Sciences Radiation Protection Manual

1. Radiation safety concerns and diagnostic reference levels for computed tomography scanners in Tamil Nadu (Livingstone et al.)

2. Establishment of diagnostic reference levels in computed tomography for select procedures in Pudhuchery, India (Saravanakumar et al.)

Ireland 1. European Communities (Medical Ionizing Radiation Protection) Regulations S.I. 478/2002

2. Medical Council: Diagnostic Reference

1. Medical Council: Diagnostic Reference Levels Position Paper

2. Establishment of CT diagnostic reference levels in Ireland (Foley et al.)

Page 59: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

38

Levels Position Paper

Japan 1. Diagnostic Reference Level of Computed Tomography (CT) in Japan (Fukushima et al.)

2. Japan Network for Research and Information on Medical Exposures (J-RIME) Diagnostic Reference Levels Based on Latest Surveys in Japan

Kenya 1. Radiation Protection Act-Chapter 243 [L.N. 171/19984]

2. Radiation Protection (Standards) Regulations [L.N. 54/1986]

3. Radiation Protection (Safety) Regulations [L.N. 160/2010]

1. National Diagnostic Reference Level Initiative for Computed Tomography Examinations in Kenya (Korir et al.)

Ontario, Canada

1. Healing Arts Radiation Protection Act R.S.O 1990, c.H.2

2. Healing Arts Radiation Protection Regulations R.R.O. 1990, Reg. 543

1. Computed Tomography Dose Variability in Ontario for Ontario Health Technology Assessment Committee (Easty and White)

Portugal 1. Portugal Decree Law No. 180/2002 For health protection of individuals against the dangers of ionizing radiation in medical exposure (translated from Portuguese)

2. Portugal Decree Law No. 492/1999 Approval of the legal and licensing and supervision regime for private health facilities with diagnostic and/or therapeutic ionizing radiation sources, ultrasound or magnetic fields (translated from Portuguese)

1. The establishment of computed tomography diagnostic reference levels in Portugal (Santos et al.)

2. Results of project Dose Datamed 2 Portugal (Teles et al.)

Switzerland 1. Radiological Protection Act Section 814.50

2. Radiological Protection Ordinance Section 814.501

1. Federal Office of Public Health’s DRLs in computed tomography (Case number R-06-06md)

2. Patient doses in CT examinations in Switzerland: Implementation of National Diagnostic Reference Levels (Treier et al.)

Texas, USA 1. Texas Radiation Control Act—Health and Safety Code, Title: Sanitation and Environmental Quality, Subtitle D: Nuclear and Radioactive Materials, Chapter 401: Radioactive Materials and Other Sources of Radiation

2. Texas Administrative Code Section 289 a. 289.203—Notice, Instructions

and Reports to Workers; Inspections

b. 289.204—Fees for Certificates of Registration, Radioactive Material Licenses, Emergency Planning and Implementation, and Other Regulatory Services

Page 60: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

39

c. 289.205—Hearing and Enforcement Procedures

d. 289.226—Registration of Radiation Machine Uses and Services

e. 289.227—Use of Radiation Machines in the Healing Arts

f. 289.231—General Provisions and Standards for Protection Against Machine-Produced Radiation

United Kingdom

(UK)

1. Health and Safety Ionizing Radiations Regulations 1999 No. 3232

2. Health and Safety Ionizing Radiation (Medical Exposure) Regulations 2000 No. 1059

3. Health and Safety Executive’s (HSE) Guidance Note PM 77 Equipment used in connection with medical exposure

4. HSE’s Regulatory requirements for medical exposure to ionizing radiation, An employer’s overview

1. Public Health England’s Doses from Computed Tomography (CT) Examinations in the UK-2011 Review

Comparison Publications

on Dose Levels

1. Dose Reduction in CT while Maintaining Diagnostic Confidence: Diagnostic Reference Levels at Routine Head, Chest and Abdominal CT—IAEA-coordinated Research Project (Tsapaki et al.)

4.3 Understanding the Jurisdictional Regulatory Structure

In addition to the review of the radiation protection publications, qualitative interviews with jurisdictional

representatives were conducted to better understand the regulatory framework of each jurisdiction. The

relationships between different organizations, whether governmental or independent, were identified to

understand the standards for institutions in each jurisdiction.

4.3.1 Expert Interviews with Jurisdictional Representatives

Semi-structured interviews with jurisdictional representatives were conducted under the approval of

University Health Network’s (UHN) Research Ethics Board for Protocol 14-7902.

4.3.1.1 Interview Questions Generation

Semi-structured interviews were conducted with CT stakeholders employed by international radiation

protection organization or provincial/state level organizations. These interviews were divided into two

parts. Part 1 focused on understanding each jurisdiction’s regulatory structure (e.g. the authority of each

organizational body, the relationship with between each authority, the decision-making process for the

approach). Part 2 aimed to identify the facilitators and barriers that each jurisdiction may have

experienced as it implemented their new regulatory approach. A fundamental qualitative descriptive

Page 61: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

40

approach, as described by Sandelowski [81], was undertaken to formulate open-ended interview questions

(Appendix A).

4.3.1.2 Recruitment Strategy

In order to be included in the study, potential participants must have a working knowledge of the

regulatory framework in the selected jurisdictions and CT scanning parameters and platforms. He/she

should have experience following the radiation protection CT standards within the jurisdiction and/or

experience implementing new CT regulations. The potential participants must be able to read, write and

understand English and be willing to participate. The participants did not receive any reimbursements or

compensation as it was expected that the formulation of dose management regulations in Ontario will

improve patient safety, which is ample incentive for healthcare professionals to participate in this study.

This study employed a maximum variation sampling strategy, which involved the purposeful selection of

participants with diverse characteristics and aims to capture the central themes that cut across a great deal

of variation [82]. The logic behind purposeful sampling was in selecting information-rich cases from

which one can learn a great deal about the issues of central importance to the purpose of the inquiry [82].

Jurisdictional representatives were identified through each responsible authority’s website. If a

representative could not be identified, a general inquiry e-mail was sent to learn the specific contact

information of the public relations person that have the best general understanding of the regulatory

framework in the respective jurisdiction. An e-mail explaining the purpose of the study, with an attached

consent form, was sent to each potential interviewee. If the jurisdictional representative was interested, an

interview date and time was set at the interviewee’s convenience. Reponses were often not returned from

general inquiry requests despite two follow-up e-mails that are sent. In situations when e-mail responses

were not received, telephone calls were placed to the responsible authority’s general inquiry line to

explain the study. Potential interviewees were identified through these calls, and interview times were

established.

4.3.1.3 Study Population

The total number of participants was 11. Participants were recruited continuously with the intention of

having a minimum of one representative for each jurisdiction. However, only 10 of the 15 jurisdictions

and international organizations had representatives who participated in the semi-structured interviews.

Potential interviewees from four jurisdictions declined participation in the semi-structured interviews, but

they agreed to provide information through written responses to the interview questions or through e-mail

correspondence. For these four jurisdictions, additional recruitment e-mails were sent to representatives

Page 62: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

41

from other organizations that also have interest in the radiation protection of CT scanners. This

recruitment was unsuccessful due to the time constraint of the study and the lack of interest from these

potential interviewees. Table 6 shows a summary of the study population. Communication with at least

one representative from each jurisdiction allowed for a better understanding of the regulatory framework,

the organizations that are involved, and the rigor of the compliance standards.

Table 6: A summary of the jurisdictions that had representatives participate in interviews, and each interviewee's affiliation

Jurisdiction Interviewee’s Affiliation Type of Interview

Australia ARPANSA Phone Interview

British Columbia, Canada

Diagnostic Accreditation Program of the College of Physicians and Surgeons of British Columbia

Phone Interview

California, USA California Department of Public Health E-mail correspondence

Euratom N/A

Germany German Federal Office for Radiation Protection

Phone Interview

IAEA IAEA and International Commission for Radiation Protection (ICRP)

Phone Interview

India Independent researcher with interest in CT Radiation Protection

In-person interview

Ireland Independent researcher with interest in CT Radiation Protection

Phone Interview

Japan Radiologist and Independent researcher with interest in CT Radiation Protection

Written answers to interview questions

Kenya Kenya’s Radiation Protection Board E-mail correspondence

Ontario, Canada Medical Physicist with interest in CT radiation Protection

Phone Interview

Portugal Independent researcher with interest in CT Radiation Protection

Phone Interview

Switzerland Federal Office of Public Health Phone Interview

Texas, USA Texas Department of State Health Services Phone Interview

United Kingdom Public Health England Phone Interview

A Euratom representative was not contacted for an interview because it was the responsibility of the

member states to interpret and transpose the Euratom directives, which resulted in a variety of regulatory

approaches in the member states. Representatives of Euratom member states selected for analysis were

contacted for interviews. The representative from IAEA was also an employee of ICRP, and so, insight

was gathered for each organization’s approach to radiation protection of CT scanners. This interview

focused on Part 2 of the questions since the IAEA and ICRP does not have direct authority over their

member states, and therefore, did not have any specific regulatory approach to discuss in Part 1 of the

interview questions.

Page 63: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

42

4.3.1.4 Setting and Procedure

Ten of the interviews with jurisdictional representatives were conducted over the phone or via an internet-

based communication application (i.e. Skype). One interview was conducted in-person. Each interviewee

should have read the consent form prior to the interview date. The purpose and methods of the study were

explained to the participant before the start of the interview, and any questions that he/she may have had

were answered. Participants were then asked to provide verbal consent before the beginning of the

interview. Once consent was received, each interview was audibly recorded using two methods: handheld

audio recorder and a laptop computer. Typewritten notes were also recorded on the laptop computer. Near

the end of each interview, consent was obtained from the interviewee to send any additional questions via

electronic means if any missing information was deemed important for the study. Follow-up

communication was conducted via e-mail correspondence.

4.3.1.5 Data Analysis

The recordings were transcribed for data analysis purposes. Answers from Part 1 of the interview were

used to construct flow diagrams to better understand the relationships between organizations that have an

interest in radiation protection in medical applications. The organizations and their purposes were

highlighted in the transcript of the interview. The connection between these organizations, and their

influence at the institutional level, were also noted.

Part 2 of the interviews focused on better understanding the experience of regulation implementation in

each jurisdiction. These questions allowed for the catalogue of enablers and facilitators to the

implementation of a regulatory framework that focuses on CT dose management. Qualitative data

collected from Part 2 was analyzed qualitatively for recurring themes following procedures for qualitative

content analysis as described by Sandelowski [81]. The transcript of each interview was systematically

analyzed to find the important factors that emerge, determine what they mean and how they fit into the

context of the discussion [81]. The transcripts were reviewed line by line in detail and the text was coded

according to themes that emerge over the course of the study using Microsoft Office. As the coding

framework was developed, the transcripts were re-analyzed for any new themes that may have emerged.

The coded themes were analyzed, relationships were identified, and patterns were described. Qualitative

descriptors and non-identifying quotations will be used to communicate Part 2’s findings in Chapter 7.

4.3.2 Construction of Regulatory Structure Flow Diagrams

Due to the intricate and complex structure of each jurisdictional model, it was important to confirm that

the jurisdictional approach to regulating CT radiation dose was understood correctly. The radiation

protection publications from the different organizations in each jurisdiction were reviewed to identify any

Page 64: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

43

authority that has a role in the regulatory approach for radiation protection of CT scanners. The data

collected from Part 1 of the jurisdictional representatives’ interviews were used to confirm the

understanding and interpretation of the relationships between the organizational bodies and their

associated publications. An influence diagram was completed for each jurisdiction to illustrate these

relationships. The influence diagram was selected to represent the relations between the organizations

because it provides a formal description of the problem and the representation is easily understood by

people with different degrees of technical proficiency [83]. Additionally, it can provide a bridge between

qualitative description and quantitative specification [83].

Figure 16 provides an example of the complex regulatory structure that may preside in the regulatory

framework for a jurisdiction. Green-coloured boxes represent the highest responsible authority that is

granted with legal authority to oversee the radiation protection in medical applications. These green boxes

are also used to characterize the written legislations that govern the CT facilities. Red-coloured boxes

represent the appointed supervisory authorities that are responsible to ensure compliance with the

legislations. Yellow-coloured boxes represent organizations or parties that do not have any legal authority

or role in the radiation protection of CT facilities, but they consult and offer scientific evidence to

strengthen the decision-making process by the responsible authorities. Additionally, any other documents

that have influence over the CT operational standards in institutions are also included in the influence

diagram. Green-coloured documents have legal authority, while yellow-coloured documents are simply

non-legislative supplemental materials that provide details regarding how to achieve compliance with the

legal documents. Appendix B shows the influence diagram of each jurisdiction’s regulatory structure.

Page 65: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

44

Institutions

Supervisory authority

Consulting organizations/parties

Governing Legislation

Governing or highest responsible authority

International Organization Legislation

Any documents that may have an influence on the

any radiation protection

authority’s actions (Some may be legally binding,

while others may just be

supplemental) Legal

Supervisory

Consultancy

Figure 16: A general influence diagram that present the approximate regulatory structure that can be found in the radiation

protection of medical applications in each jurisdiction

4.4 Discussion

The review of the radiation protection publications showed the intended regulatory structure for medical

exposure radiation protection. In conducting the semi-structured interviews, it was realized that the

intended regulatory structures were not in place due to limited human and financial resources. Discussion

will focus on the factors and organizations that were deemed to have a significant impact on the

regulatory structure for each jurisdiction. Unique aspects and the apparent discrepancies between the

radiation protection publications and actual existing regulatory structure will also be discussed.

4.4.1 International Radiation Protection Organizations

There are two international radiation protection organizations that have publications included in the

analysis: Euratom and IAEA. Euratom is a centralized organization with the same membership as the

European Commission, that was founded in 1957 to continually improve nuclear safety, security and

radiation protection [84]. Recently, a strong emphasis has been put on the development of research

programmes aimed at attaining the highest level of protection from radiation, which includes a focus on

the medical uses of radiation [85]. Its publications, Directives 97/43/Euratom and 2013/59/Euratom, are

legally binding for all member states because Euratom was founded on an international treaty signed by

the sovereign states that provided Euratom with the power to act as an international legal persons [84].

The decisions of The Council of Ministers, which is comprised of representatives of the governments of

Page 66: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

45

member states [84], have substantial influence over the radiation protection situation in each member

state.

Of the other two well-known radiation protection organizations, only IAEA’s standards were included in

the analysis because ICRP was described as “a toothless body” by a representative from the organization

due to its lack of legislative authority. The interviewee explained that ICRP is “registered as a charity”

and has no legal authority over countries, which suggests it did not meet the inclusion criteria for

publications from international radiation protection organizations. However, the representative from the

ICRP/IAEA was adamant about the level of scientific advice that is coming from ICRP on radiation

protection.

Representative of ICRP/IAEA: “ICRP’s recommendations are used by the IAEA to produce safety

standards, so ICRP—whatever it may be—has a very valuable place in the field of radiological

protection.”

On the other hand, IAEA is often confused as a regulatory body with legal authority. However, the

findings from the semi-structured interview revealed that this is a misconception.

Representative of ICRP/IAEA: “Maybe people think that IAEA is a super regulator, which (it) is

not at all. It acts as a sort of regulator in safeguards […] IAEA does not have any power to

regulate or push its regulatory systems on the countries. Theoretically, this is the situation that

IAEA model regulations or requirements are not binding on member states. They are not

mandatory. […] But, practically, what happens is since most developing countries need

assistance of IAEA, so indirectly, IAEA says ‘okay, we will give you assistance when you follow

our safety standards.’ In a way, all developing countries need the IAEA’s assistance so then

indirectly, IAEA safety standards become sort of mandatory.”

The pseudo mandate of IAEA standards was considered in the jurisdiction selections process. The IAEA

standards were included in the analysis because its target users are often developing countries, which

provides a stark contrast to the Euratom standards that are designed for more economically advantaged

countries. An evaluation and comparison of these standards (Chapter 6) were expected to provide

interesting insight into the different possible approaches to radiation protection that require varying levels

of financial resources and technical expertise.

4.4.2 European Countries

Five European countries were included in the analysis: Germany, Switzerland, UK, Portugal and Ireland.

Each of these countries are obligated to interpret and transpose Council Directive 97/43/Euratom into

jurisdictional legislation, and so, the regulatory structure of each country should be similar. However, the

existing regulatory structures are actually quite different. Switzerland and the UK have centralized

Page 67: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

46

regulatory structures where the national-level governing health organizations—Switzerland’s Federal

Office of Public Health and UK’s Department of Health—are appointed as the highest responsible

authorities for radiation protection in medical applications. The two countries differ in the supervisory

aspect of the regulations because UK contracts a non-governmental organization to conduct periodic

inspections whereas the Federal Office of Public Health is also responsible for inspections. Germany,

conversely, has a less centralized regulatory structure. There are national governing legislations

formulated by the Federal Ministry for Environmental and Nuclear Safety, but these regulation are

interpreted by the German State Offices. Furthermore, local medical authorities in the German States are

appointed with the responsibility of ensuring compliance. Germany, Switzerland and the UK all have

designated resources to update DRLs periodically. The only caveat to the UK’s approach is a discrepancy

in terminology when referring to the recommended dose levels, which may result in confusion for CT

stakeholders who are not actively involved in the development of the regulatory process. The UK has a

longstanding history of developing “national reference doses” for various exam types, which serve the

same purpose as DRLs.

Representative from Public Health England: “There are national reference doses that come out

from here (Public Health England) that are for all intents and purposes national DRLs [… ]Now

we have an agreement that we can formally call them (the national reference doses) national

DRLs […] the sad thing is when you look on our website, you find quite old values but if you

search for national reference doses, then you find quite new values”

Contrastingly, Ireland and Portugal have not had the same level of financial and human resources to

actively interpret and implement Council Directive 97/43/Euratom, which has resulted in a lack of official

DRLs. The European Commission referred Ireland to the European Court of Justice to the non-

transposition of the Directive on Medical Exposures in 2002 [67]. Likewise, Portugal also experienced

some difficulty in implementing the Directive.

Independent researcher from Portugal: “We should have transposed it (Directive 97/43/Euratom)

in the end of 2000. However, we paid a lot of money because according to European rules, we

take time to translate and we didn’t transpose […] we were missing the time, so we just translate

it instead of transpose it. I think that is something that should be more adapted to our reality

because we are in Europe and each country has differences in the constitution.”

Despite Ireland’s transposition of the Directive, the Medical Council who was the appointed supervisory

authority did not have the resources after the initial set-up of the DRLs and the regulations. When asked

about DRL updates and clinical audits, the interviewee from Ireland described that “no one had ultimate

responsibility until the medical exposure radiation unit took it on. So between 2002 and 2009, nothing

essentially was done.” Similarly, Portugal’s interviewee explains that there are no official DRLs at this

point, but rather, “we (Portugal) just have the ones that we proposed. And we have some (dose

levels) studies like myself.” The financial crisis in Europe has resulted in strict fiscal austerities

Page 68: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

47

for Ireland and Portugal, which has evidently affected their spending to ensure patient dose

management of CT examinations.

Independent researcher from Ireland: “Because after everything that’s going on in the country

and the economy […]we have less manpower on the ground but probably, the services have

actually increased.”

Independent research from Portugal: “Here in Portugal, even if you do not have money, you get

healthcare. Of course, normal people pay and with the crisis, we pay a little more in the last few

years. […] But before the crisis, we changed a lot of technologies especially in private

institutions, the most known private clinics changed every few years.”

4.4.3 Australia

Australia’s structure is the most similar to the radiation protection regulatory structure in Canada.

Representative from ARPANSA: “We have 8 states—similar to your provinces. [..] Each of our

states is a separate government system and we have a federation or a federal government, which

ARPANSA is part of.”

The function of ARPANSA is similar to the Radiation Protection Bureau (RPB) of Canada since both

organizations aim to promote and protect the health of their respective citizens by managing the risks

posed by radiation exposure. However, the authority of ARPANSA appears to be greater than that of

Canada’s RPB. When asked about the ARPANSA’s Code of Practice, the representative from ARPANSA

explained that “we have medical codes for radiation, and designated conditions of license both for the

practice itself and also, the operators of the equipment […] it becomes a regulatory document—a legal

document—when it’s picked up by the states’ legal systems.” The analogous document from RPB is

Health Canada’s Safety Code 35, which was prepared to “provide specific guidance to large medical

radiological facilities where diagnostic and interventional radiological procedures are routinely performed

using radiographic, radioscopic or computed tomography equipment [76].” This guidance is not legally

binding for CT facilities because the explanatory notes of Safety Code 35 also states that “the authorities

listed in Appendix V should be contacted for details of the regulatory requirements of individual

provinces and territories [76].”

In a comparison of the Canadian and Australian regulatory structures, it would appear that Australia has

taken more initiative in regulating CT radiation dose exposure for patients. Although ARPANSA cannot

directly regulate CT facilities because hospitals are under individual state rule, the organization has found

an alternative method to ensure quality assurance of institutions through monitoring of dose levels.

Representative from ARPANSA: “We have got representation onto DIST (diagnostic imaging

accreditation scheme) and we have managed to get them to include parts of our code as a

separate part of their accreditation process. […] part of our code is practices need to develop

DRLs and compare it against national DRLs, and if there is any discrepancy, then they do work

Page 69: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

48

with it to optimize and fix it up. […] If they lose accreditation, they lose their funding, so we are

sort of hitting them at the money side of it.”

Furthermore, Australia has taken a proactive approach in radiation protection of medical exposures by

defining DRLs in a similar manner to the Eurotam member states even though it is not under the same

legal framework. The representative from ARPANSA attributes the organization’s enthusiastic

approach to ARPANSA’s close working relationship with the ICRP and the IAEA.

Representative from ARPANSA on DRLs: “The hospital produce what’s called facility DRLs and

the data that comes in from all the practices gets put together and that’s how we generate the

national DRLs.”

Representative from ARPANSA on IAEA influence: “Our CEO is actually from Sweden and he is

very keen, and he has been involved with the ICRP and the IAEA and NCR for quite a while, so

he would like to see the Australian framework nearer the European framework, which we are sort

of moving towards.”

4.4.4 North American Jurisdictions

Every State in the United States of America (USA) has its own governmental public health system that

provides and oversees an array of public health services [86]. One of which is management of ionizing

radiation in medical applications. The regulatory frameworks for medical ionizing radiation vary in rigor

between States, with some focusing only on technical requirements while others have managed to include

standards for radiation dose optimization. The most notable frameworks that target radiation dose

management are new regulations that have been enacted in California and Texas, respectively.

Representative from Texas: “We also interestingly enough had visitors from South Korea that

came and spent three days with us last year on the CT and fluoro rules, and they also stopped in

California and spent a day there. But they are looking at moving forward with some of the same

initiatives.”

California has focused their framework on the mandatory accreditation and dose reporting from CT

facilities, whereas Texas’s approach only requires the establishment of radiation protocol committees in

each institution that regularly reviews standard clinical protocols and dose levels.

Representative from Texas: “We had physicists from ACR (American College of Radiology) as

well as AAPM (American Association of Physicists in Medicine) as well as inspectors and

technologists on that committee. We worked together to see what we could do that wold make a

difference, but not be overly burdensome that all facilities would be able to follow and develop

some kind of plan.”

When interviewees discussed the adoption process for these new standards, the representatives from both

states claimed smooth implementation and uptake. This can be attributed to the rigorous standards that

many of the CT facilities already meet as healthcare provides under the Medicare Program.

Representative from California: “From an enforcement perspective, most facilities we have

inspected have found some method of complying with the law. […] Many already were accredited

Page 70: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

49

by the American College of Radiology (ACR) due to the federal reimbursement requirements.

Facilities that seek federal reimbursement for CT scans must be accredited. Many hospitals had a

basic framework to build on anyway.”

Likewise, some of Canada’s provinces and territories have also been making efforts to manage CT

radiation doses. British Columbia uses an accreditation approach that lends complete authority of the

diagnostic imaging facilities to the College of Physicians and Surgeons of British Columbia under the

Health Professions Act. This unique approach regulates the health professionals’ actions by limiting the

practice of the College’s members to accredited facilities. Another province that has recently taken

initiative to manage patient radiation dose exposure is Manitoba. The intended Radiation Protection Act is

currently awaiting approval by the Legislative Assembly of Manitoba. Denoted Bill 37, but its proposal

includes clauses that mandate establishment of quality assurance programs, implementation of periodic

inspections, and the maintenance of patient dose records [87].

4.4.5 Developing Jurisdictions

Developing jurisdictions, such as Kenya and India, face the unique challenge of dose optimization with

limited financial resources and technical expertise. There is a growing demand for radiology services due

to global increase in illness, the increase in aging citizens and the rise of urbanization [88]. In fact, there

has been tremendous growth in the acquisition of multi-slice CT scanners in India [88]. In preparation for

the imminent growth of CT scanner usage, Kenya and India have both pre-emptively established

minimally burdensome licensing standards that focus on the technical specifications of CT scanners that

have been acquired by institutions. The independent researcher from India explained that the licensing is

free to minimize the opportunity for bribes and corruption. Furthermore, Kenya has been proactively

increasing compliance standards for CT facilities, despite only having 11 CT scanners countrywide in

2010 [71].

Representative from Kenya’s RPB: “There are Certified Technical Support Operators who carry

out Safety Assessments of the Radiation Facilities & QC for X-ray machines in medicine. We are

in the process of developing regulations and guidelines for use in the field. The RPB inspects all

radiation facilities in the Country prior to licensing.”

But perhaps, the most interesting information learned from the correspondence with the representative

from Kenya’s RPB is the establishment of Afrosafe despite the relatively low number of CT scanners that

are present in African Countries. For example, Uganda and Zambia only had six and three CT scanners

respectively nationwide in 2010 [71]. The mission statement of Afrosafe is “to ensure that throughout

Africa, the benefits outweigh the harms for all individuals exposed to radiation for screening, diagnosis,

or therapy at all levels of care [89].” Representatives from Kenya, Uganda, Tanzania, South Africa,

Rwanda, Zambia, Ghana, and Nigeria all verbally assented to the Afrosafe declaration, which aligns with

Page 71: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

50

the Bonn Call-for-Action from the IAEA and World Health Organization (WHO), at Afrosafe’s launch

during the Pan African Congress of Radiology and Imaging [89], [90]. Details of the Bonn-Call-for-

Action can be found in Appendix C.

4.4.6 Japan

Of the different jurisdictions selected for analysis, Japan’s regulatory structure can be deemed as the most

unique and surprising. Despite having the highest number of CT scanners per capita at 101.3 per million

population [70], Japan does not have any regulations surrounding the use and operation of CT scanners.

The only legislation that governs the use of ionizing radiation in medical applications is the Medical

Supplies Act, which focuses on the sale and import of radioisotopes [91]. However, an independent

researcher from Japan explained that the country does have professional organizations that evaluate the

professional standards of technologists and their certifications. Although there is minimal government

attention provided for the radiation protection in medical exposures, researchers at the National Institute

of Radiological Sciences (NIRS) have taken notice of the increasing public awareness and concerns about

potential radiation health effects. In 2010, the NIRS established the Japan Network of Research and

Information on Medical Exposure (J-RIME) [90]. J-RIME aims “to exchange information and to facilitate

collaboration of academic societies, manufacturers and the government for radiation protection in

medicine [92].” The results of J-RIME’s first project to establish DRLs for Japan have been published in

2015. Nonetheless, the legality of Japan’s DRLs remains questionable without legislated support.

4.5 Summary

Through review of the radiation protection publications from each jurisdiction and semi-structured

interviews with jurisdictional representatives, the unique regulatory approaches to radiation protection of

medical exposures were interpreted and displayed using influence diagrams. It is evident that each

jurisdiction, whether it has a low number of CT scanners like Kenya or the highest number of CT

scanners per capita like Japan, is aware of the increasing public concerns and potential hazards stemming

from the great reliance of CT scanners in medicine. Ontario, likewise, will benefit from the adoption of a

regulatory framework to ensure dose optimization in CT facilities. The analysis of the regulatory

structures showed that jurisdictions benefit from the availability of guidelines for regulations, such as the

Council Directive 97/43/Euratom. Health Canada’s Safety Code 35 functions as an analogous guidance

document that provides basic standards for implementation in each province or territory. The variability

in regulatory approaches suggest that the adaptation of standards should be adjusted to the financial and

human resource availability of each jurisdiction while still maintaining a minimum standard of practice.

Page 72: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

51

5 Assessment Framework Development

The second objective is to design an effective and easy to use assessment instrument to evaluate the

quality of the jurisdictional models. The evaluation criteria will target the critical aspects of legislations

and clinical guidelines that are predicted to affect the effectiveness of implementation. Two iterations

were required to design a comprehensive assessment instrument. The assessment instrument, denoted as

Regulatory Assessment for Computed Tomography (hereafter referred to as RACT), is specially designed

to systematically assess and compare the radiation protection publications, and regulatory structures that

have been developed to optimize CT radiation dose.

5.1 RACT 1 Design Methodology

The design of RACT 1 was a pilot study to determine the feasibility of generating a simple yet

comprehensive approach to evaluating the various jurisdictional models for CT dose management of

patients. In its design, the six jurisdictions from the preliminary selection process were considered. The

final design for RACT 1 and the associated rater worksheets are detailed in Appendix D.

5.1.1 Identification of Themes in the Radiation Protection Publications

The italicized radiation protection documents in Table 5 were for thematic analysis. These documents

were written to include all medical exposure to ionizing radiation, which is generally defined as any

exposure to ionizing radiation incurred by patients as part of their own medical or dental diagnosis or

treatment [93]. The relevant documents often also incorporate instructions for the occupational exposure

personnel, the exposure of volunteers in biomedical research, medico-legal exposure, and the exposure of

those who voluntarily help in the support and comfort of patients [93]. Due to the expansive amount of

information in each of the documents, it was important to select only those clauses that pertain to CT use

and operation to facilitate the subsequent comparative analyses.

Themes were generated through an iterative process where the textual data were reviewed line by line in

detail for each document [94]. When a recurring concept was apparent across different documents, a

thematic label was assigned [94]. Once the themes were developed, the publications were reviewed line

by line for more specific sub-theme criteria that recur in the documents. Sub-theme criteria can be viewed

as “considerations” that must be fulfilled to satisfy the implementation of each theme. These themes, as

summarized in Table 7, formed the basis of each analyzed radiation protection document.

Page 73: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

52

Table 7: The preliminary categorization of themes based on select jurisdictional radiation protection documents

Theme Considerations

Technical requirements

Facility and equipment requirements for CT installation Acceptance testing and equipment maintenance Quality control testing Frequency of assessments and associated consequences

Operation requirements

Licensing requirements for operating personnel Justification requirement for performing CT scans Radiation safety officer role and responsibilities Establishment of standard operating protocols Procedures for vulnerable populations Shielding requirements Evaluation of radiation output or patient doses

Radiation safety committee/ Quality assurance programs

Members, roles and responsibility of the committee Extent of focus on the “as low as reasonably achievable” (ALARA) principle for radiation dose Frequency of committee meetings and reporting requirements for the committee Management options in situations of incompliance

Radiation dose reporting

Authoritative body that requires the reports The mandated situations that have to be reported Information that must be included in dose reports Frequency of reporting Consequences of incompliance

Diagnostic reference levels

Definition, development of DRLs Availability of DRLs for vulnerable populations Frequency and method of DRL updates (e.g. benchmarking) Training and education regarding DRLs at the institution level Enforcement and consequences of DRL exceedances

5.1.2 Identification of Domains for RACT 1

Due to the clinical nature of the documents included for analysis, they were treated as clinical guideline-

type documents that are designed to guide decisions ad criteria regarding diagnosis, management and

treatment in radiation protection of patients in medical applications [95]. From a broad-based literature

search, two tools for appraisal of guideline quality—the Guideline Implementability Appraisal (GLIA)

[96] and the AGREE Instrument [97]— were examined to identify factors that are important for smooth

implementation of new standards. Factors that could not be evaluated simply by reviewing the radiation

protection documents (e.g. effect on process of care) and redundant factors were eliminated through

discussion and consensus with the other reviewer who also participated in the jurisdictional models

evaluation process. Three domains—comprehensiveness, executability, and rigor— were selected for

RACT 1 because discussion hypothesized that many of the attributes presented in the two guideline

appraisal tools could be grouped together. Table 8 summarizes the different attributes that were presented

in the two literature articles and discusses each attribute’s significance in the evaluation of radiation

Page 74: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

53

protection documents. The selected domains, as highlighted in green in Table 8, contained characteristics

that if performed well, would improve the implementability of the document. The attributes highlighted in

red in Table 8 were not selected for RACT 1 because discussion between reviewers predicted that the

evaluation of these attributes would require information that cannot be obtained from reviewing the

radiation protection documents alone.

Table 8: A summary of the attributes that were presented in the GLIA and AGREE instruments. The attributes that were

translatable for RACT 1 were grouped together and re-defined to generate broader domains

Attribute Description Domain category or justification for exclusion

Scope and Purpose (AGREE)

concerned with the overall aim of the guideline, the specific health questions, and the target population [97]

-Comprehensiveness: The general characteristics were combined into the comprehensiveness domain to ensure that the documents as a whole included sufficient information

Global (GLIA) General characteristics of the guideline as a whole [96]

Stakeholder involvement (AGREE)

focuses on the extent to which the guideline was developed by the appropriate stakeholders and represents the views of its intended users [97] -All of these attributes pertain to the

development of the document -They were not included in the domain selection for RACT 1 because it was thought to be difficult to evaluate the development of legislative documents due to the limited information specific to the synthesis of legislation

Editorial Independence

(AGREE)

concerned with the formulation of recommendations not being unduly biased with competing interests [97]

Rigor of development (AGREE)

relates to the process used to gather and synthesize the evidence, the methods to formulate the recommendations, and to update them [97]

Apparent validity (GLIA)

Degree to which the recommendation reflects the intent of the developer and the strength of the evidence [96]

Presentation and formatting (GLIA)

Degree to which the recommendation is easily recognizable and succinct [96]

-Executability: All of these attributes pertain to the decision-making process and criteria for different situations. The presentation of the document and its instructive qualities were hypothesized to affect the usage and executability of recommended action plans.

Clarity of presentation (AGREE)

deals with the language, structure, and format of the guideline [97]

Applicability (AGREE)

pertains to the likely barriers and facilitators to implementation, strategies to improve uptake, and resource implications of applying the guideline [97]

Flexibility (GLIA) Degree to which a recommendation permits interpretation and allows for alternatives in its execution [96]

Decidability (GLIA) Precisely under what conditions to do something [96]

Executability (GLIA) Exactly what to do under the circumstances defined [96]

Measurable outcomes (GLIA)

Degree to which the guideline identifies markers or endpoints to track the effects of implementation of this recommendation [96]

-Rigor: The adoption of clinical changes should have minimal influence on existing workflows. Rigor, therefore, defines the extent to which the recommended actions require practice

Effect on process of care (GLIA)

Degree to which the recommendation impacts upon the usual workflow of a care

Page 75: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

54

setting [96] changes.

Novelty/Innovation (GLIA)

Degree to which the recommendation proposes behaviors considered unconventional by clinicians or patients [96]

-Not deemed to be important for the radiation protection of patients in medical applications -Patient safety should be prioritized, so new, untested methods should be avoided

Computability (GLIA) Ease with which a recommendation can be operationalized in an electronic information [96]

-Not applicable to RACT 1’S purpose

5.1.3 Application of RACT 1

RACT 1 employs a 5 point Likert Scale from 0 to 4, with 0 being the lowest. The six preliminary

jurisdictions were scored in each of the three domains for every theme listed in Table 7. Two reviewers,

including the author of this thesis, participated in the evaluation process. The second reviewer had

minimal knowledge of the different approaches to radiation protection of CT scanners, which allowed for

the usability of the assessment instrument to be induced. A highly usable instrument should result in a

high inter-rater reliability, regardless of the technical knowledge of the user and without the need for

interim discussions regarding the interpretation of the evaluation criteria.

The weighted Cohen’s κ for each theme, and 95% confidence interval that the agreement is better than

chance were calculated after each round of independent evaluation by the two reviewers. The Fleiss

Benchmark Scale was used to evaluate the level of agreement, where κ values <0.40, 0.40 to 0.75, and

>0.75 represent poor, intermediate to good and excellent agreement, respectively. If inter-rater reliability

was insufficient (aggregate κ <0.75), a discussion was held to propose clarifications for the domains and

their applications. Iterations of evaluations occurred until aggregate κ ≥0.75 was achieved. Final scores

were achieved through consensus once κ was satisfactory, which facilitated subsequent data analysis (i.e.

Pearson correlations).

5.1.4 Results and Discussion of Preliminary Analysis using RACT 1

Table 9 presents the results of the inter-reliability test for each evaluation round per theme, and the 95%

limits of agreement. The initial round of evaluations revealed poor agreement for the technical

requirements. Discussion revealed ambiguity regarding which domain should encompass CT specificity

when requirements were listed in the radiation protection document. It was agreed upon that specificity

should be a characteristic of comprehensiveness, thereafter, because a comprehensive document should

detail recommended action plans for a range of circumstances. After the second round of evaluation, each

theme achieved κ >0.75, with an aggregated inter-rater reliability of κ =0.830±0.034.

Page 76: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

55

Table 9: Inter-rater reliability for each theme (expressed as Weighted Cohen's κ ± 95% C.I.)

Round Technical

requirements Operational

requirements Radiation safety/Quality

assurance programs Radiation dose

reporting

Diagnostic reference

levels Aggregate

1 0.011± 0.155 0.714± 0.095 0.676± 0.076 0.431± 0.107 0.537± 0.122 0.504± 0.053

2 0.757 ± 0.092 0.759 ± 0.092 0.924± 0.051 0.752± 0.110 0.868± 0.058 0.830± 0.034

The finalized aggregated domain and theme scores as agreed upon by the raters are summarized in Table

10. Technical and operating requirements were expected to be high scoring themes for all jurisdictions

because each jurisdiction was selected for its recent updates to regulatory structure to include oversight of

CT. However, the jurisdictions that had accreditation standards included in the analysis (i.e. British

Columbia and California) performed better because of high CT specificity. The scores may not provide an

accurate comparison of the regulatory structures because accreditation guidelines are written with the

purpose of providing comprehensive instructions for all foreseeable circumstances, and therefore, offer

California and BC an advantage in this preliminary analysis. A widespread sample of document types for

each jurisdiction was obtained for subsequent evaluations with later designs of RACT.

Table 10: Final aggregated domain and theme scores for each jurisdiction. The theme abbreviations are explained in the List of

Abbreviations.

Domain British Columbia Ontario California Texas Germany Ireland

Executability 15 5 17 11 11 10

Comprehensiveness 16 2 17 10 10 10

Rigor 13 4 17 9 13 12

Theme

Technical requirements 11 4 10 6 4 4

Operational requirements 10 2 10 6 7 7

Radiation safety/Quality

Assurance Programs 11 0 10 9 5 6

Radiation dose reporting 9 5 12 4 7 6

DRLs 3 0 9 5 11 9

Total 44 11 51 30 34 32

The Pearson correlation coefficient was calculated for the domains. There were strong correlations

between the domain scores for the jurisdictions (Table 11). The scores of the three domains tend to

increase or decrease in a coupled fashion, which suggests carry over effects from one domain to the other

two.

Table 11: Pearson correlations among the domain scores

Executability Comprehensiveness Rigor

Executability 1.0000

Page 77: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

56

Comprehensiveness 0.9905 1.0000

Rigor 0.9102 0.9124 1.0000

5.1.5 Limitations of RACT 1 and Lessons Learned

The pilot study with RACT 1 contributed to the next iteration of RACT design. The biased results of

RACT 1 towards jurisdictions with accreditation guidelines and feedback from the reviewers revealed the

limitations of RACT 1, and informed the design of RACT 2.

5.1.5.1 Difference in Document Types

A more detailed review of the regulatory structure of the jurisdictions revealed that different purposes are

served with different document types. RACT 1 combined analysis for radiation protection legislation and

other supplemental materials, such as accreditation standards. This was a limitation in the design of

RACT 1 because it eliminated important attributes that were critical for the development and usage of

legislation or supplemental documents. Reviewers agreed that subsequent iterations of RACT 1 should

separate the different types of documents for analysis. Legislations are intended to be broader rules, do

not require as much explanation for their requirements, and cannot be designed to address every

circumstance [98]. Legislative documents, therefore, should not be evaluated for attributes that are

dependent on the specificity of information. Contrastingly, supplemental documents should be designed

to address all foreseeable situations [95], and so, a large factor in determining the quality of supplemental

documents would be the specificity of the recommended actions. The division of document types should

allow for more effective evaluations of radiation protection publication quality.

5.1.5.2 Low Reliability of Likert Scales

Extensive discussion was required to reach a high inter-rater reliability, which suggests that the design of

RACT 1 was ambiguous and unclear. The use of the 5 point Likert Scale contributed to the inconsistent

scoring as the response categories were effective in providing a relative rank order for the reviewer

between jurisdictions, but the intervals between the values could be presumed equal [99]. Furthermore,

Likert Scale evaluations also require a level of judgement from the reviewers in their analysis, which

differed between raters [97]. Quantitative measures for the quality of the radiation protection publications

should be used whenever possible to provide more discrete analysis of the domains. For example,

discussion could be converted into a quantitative measure by synthesizing a checklist for fulfillment of

possible clauses for the publications. This was hypothesized to provide a more discrete analysis of the

comprehensiveness domain.

Page 78: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

57

5.1.5.3 Ambiguity of Themes and Domains

The initial round of evaluations revealed some confusion regarding the criteria that the “Technical

requirements” theme encompasses. Extensive discussion was required for reviewers to agree upon the

elements that should be evaluated as part of the “Technical requirements” theme. Secondly, the Pearson

Correlation Coefficients in Table 11 show strong carryover effects, which suggest ambiguity of the

domain definitions. Rigor and executability appeared to encompass too many related constructs. This

added confusion to the evaluation process for the reviewers. For example, the enforcement actions may

require large amounts of evidence to be recorded to achieve compliance, but the enforcement frequency

may be low. The opposite extremes within the same domain make it difficult to score the jurisdiction for

the rigor domain. Discussions revealed that additional domains should be formed to increase the

specificity of each domain’s evaluation criteria.

5.2 RACT 2 Design Methodology

The design of RACT 2 took into consideration all of the radiation protection publications from each

jurisdiction in Table 5. This iteration of the RACT instrument aimed to increase clarity and usability.

RACT 2 incorporated the feedback from RACT 1’s pilot study to include separate sections for different

publication types, the use of quantitative measures to ensure better inter-rater reliability and the re-

definition of themes and domains to have more specific evaluation criteria.

5.2.1 Development of the Comprehensiveness Checklist

The comprehensiveness checklist was structured to increase the quantitative measures incorporated into

RACT 2. This quantitative value for comprehensiveness was used to compare the extent of fulfillment of

the radiation protection clauses from each jurisdiction. The inclusion of specific clauses in the

publications is a binary measurement and not subject to interpretation, which should ensure a high inter-

rater reliability. Some of the publications are general radiation protection documents that include the

industrial use of ionizing radiation or radioactive materials, and so, the documents were required to be

reviewed for clauses that pertain to CT use and operation. These specific clauses from each publication

were translated verbatim into a Microsoft Word document (hereafter denoted as the textual data).

A general inductive method, similar to the method used in the generation of themes for RACT 1 (Section

5.1.1), was employed to development of the themes in the comprehensiveness checklist. The textual data

from each publication was reviewed line by line. When a recurring concept was apparent across the

different documents, a code was assigned. Learning from RACT 1’s design experience, each highlighted

concept was less general. For example, “installation requirements” was used rather than the general code

Page 79: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

58

of “technical requirements”. Once the codes were assigned, they were reviewed for related constructs that

could be grouped together to form an overarching category (hereafter referred to as themes). The related

constructs in each theme were then denoted as sub-themes. After the confirmation of themes and sub-

themes, the textual data were reviewed again line by line to extract the unique ideas and standards that

each jurisdiction has employed to fulfill each sub-theme. Since the “key items” were described using

different terminology by each jurisdiction, the related ideas were reviewed and made into a general

fulfillment criteria before its inclusion in the comprehensiveness checklist. These themes are described:

1. General provisions: Radiation protection publications often contain very dense material, so

general provisions pertain to the explanation of the document as a whole. Key items of this theme

focus on the information that is required for users to understand and fulfill the standards of the

document.

2. Responsible authorities: Many of the legislative documents are drafted by the respective

legislative assemblies, but the oversight for inspection, improvements and compliance may be

appointed to different organizational bodies. Furthermore, some jurisdictions also have consulting

bodies that do not have legal authority, but are integral to the radiation protection efforts. Key

items of this theme focus on information that is required to understand the regulatory structure of

each jurisdiction.

3. Licensing and accreditation: Licensing of CT facilities often focuses on the technical aspects

whereas accreditation provides a more comprehensive standard that include clinical workflows

checks, personnel checks and other operational requirements. Key items in this theme focus on

aspects that explain the process for users to efficiently obtain a license in the respective

jurisdictions.

4. Technical requirements: These requirements refer to the aspects that are intrinsic to the CT

scanner system design. Key items of this theme focus on the technical standards that must be

fulfilled to maintain functionality of the system during the entire CT’s life cycle (i.e. from

installation to decommissioning).

5. Facility requirements: Due to the use of ionizing radiation in the facilities, the rooms must be

specially designed to ensure patient, staff and public safety. Key items of this theme focus on the

aspects of the facility layout, and other related measures that are required to ensure safety for

anyone that may be in the proximity of the ionizing radiation equipment.

6. Operational requirements: This theme refers to the clinical workflows and requirements that

must be fulfilled to maintain a license or accreditation. Key items of this theme focus on aspects

that must be fulfilled by each institution in order to continue performing CT services for patients.

7. Personnel requirements: This theme pertains to the qualified professionals who are required to

be present and/or consulting at the institutional level. Key items of this theme focus on aspects

that define each professional category and any other relevant information that are required for CT

facilities to fulfill human resource requirements.

Page 80: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

59

8. Patient Records: The medical records of patients should provide sufficient detail such that

decisions for ongoing care for a patient can be made accurately. Cumulative doses, for example,

and imaging records should be provided for physicians to accurately assess the need for

subsequent image acquisitions. Due to the confidential nature of medical information, the sharing

of patient records should be secure.

9. Radiation protection/Quality assurance committee: Radiation protection and quality assurance

have been prioritized in recent years. To ensure that quality assurance is consistently considered

at the institutional level, financial and human resources must be dedicated to regularly review and

update targets. Quality assurance is often ensured through the establishment of local committees.

Key aspects of this theme focus on information that are required for institutions to form an

accountable radiation protection or quality assurance committee.

10. Emergency situations and event reporting: Radiation incidents can be described as events that

occur where patients or the public are exposed to higher radiation doses than planned. These

incidents must be investigated at both the institutional and responsible authority level. Key

aspects of this theme address the process that CT facilities must undertake when radiation

incidents occur.

11. Diagnostic reference levels: Diagnostic reference levels are a practical tool to promote the

assessment of existing protocols since they represent the typical doses that are administered at an

institution (i.e. institutional DRLs) or within a jurisdiction (i.e. official jurisdictional DRLs) for

routine scans [100]. Key items of this theme focus on information that are required for CT

facilities to establish and monitor facility DRLs. Furthermore, evaluation criteria for the

implementation of jurisdictional DRLs and their role in the CT facilities are also documented.

12. Results of non-compliance: Radiation protection in medical exposure legislations are designed

to provide standards for operational facilities with ionizing radiation. There should be

consequences when these standards are not fulfilled. Keys of this theme focus on the

consequences for CT facilities in cases of non-compliance.

5.2.2 Legislation Assessment

Legislation is normally enacted by the governing body of legislative assembly to address a specific

economic, social or political need [101]. Radiation protection publications in Table 5 can be considered

“legislation” when they are legally binding and can be enforced by the courts. The legislative documents

are written to translate governmental policy decisions into implementation solutions that can achieve the

intended objective [102]. They are written to withstand statutory interpretation, so legislation does not

unambiguously and specifically addresses all matters [98]. Written words may change in meaning over

time and new technologies and cultures appear to make application of existing laws difficult [98].The

purpose of legislation should be considered when selecting the domains for legislation assessment.

Page 81: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

60

5.2.1.1 Selection of Legislation Assessment Domains

A broad-based literature review for articles that focus on assessing the content, development, presentation

and implementation of legislation was performed to identify critical attributes that affect the quality of

legislative documents. The preliminary search for evaluation of legislations revealed that these articles are

often subject-specific, but there has been a lack of published research regarding the assessment of

radiation protection legislation. Due to the specificity of subject-specific legislation evaluations, they

were inapplicable to this study. The literature search, therefore, focused on articles that address the quality

of general regulatory policies. Each article was reviewed for indicator descriptors that have been noted as

being influential on the quality of legislation. Articles were reviewed until there was an apparent

saturation of indicator descriptors. Saturation was defined as the point when additional articles did not

reveal new descriptors [103]. From this search, the following articles were identified as relevant:

1. Evaluating the Impact of Regulation and Regulatory Policy (Coglianese, 2012): This paper

focuses on explaining the need for indicators to measure the outcomes of regulatory policy and

provides a framework for systematically evaluating the performance of regulations [101].

2. Evaluating Regulatory Management Tools and Programmes (Radaelli and Fritsch, 2012):

This paper focuses on measuring the performance of regulatory instruments by appraising the

various indicators that have been perceived as suitable for measuring the performance of reform

programmes [104].

3. The Economic Impact of Regulatory Policy: A literature review of quantitative evidence

(Parker and Kirkpatrick, 2012): This paper provides a critical literature review of the quantitative

measurements and evidence that have been used to analyze the impact of regulatory policies

[105].

4. An exposition of legislative quality and its relevance for effective development (Aitken,

2013): This paper describes the characteristics of quality legislation and the functional elements

of the law development and implementation process by reviewing international organization’s

interpretation of effective legislation [102].

5. Guide to Making Federal Acts and Regulations: 2nd Edition (Government of Canada Privy

Council Office, 2001): This government document describes the steps to transform policy into

effective Federal Acts and regulations [106].

6. Good Governance: Rule of Law, Transparency and Accountability (Johnston): This paper

provides examples of good-governance efforts and explains the steps for improving participation

of citizens and the structure of institutions [107].

7. A Framework for Analyzing Public Policies: Practical Guide (Institut national de sante

publique Quebec, 2012): This paper provides insight into the dimensions that should be analyzed

in the evaluation of public policies [108].

Page 82: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

61

The indicators and their associated descriptions were analyzed as textual data. A general inductive

method was used to identify recurring themes for the quality indicators. Related indicators were grouped

together to form overarching categories, which were denoted as domains. Some indicators were

impossible to evaluate through simple analysis of the radiation protection legislation, and so, they were

eliminated for RACT 2’s development. For example, “unintended effects” was mentioned in the Institut

national de sante publique Quebec’s article as an important dimension for analysis of public policies

[108], however, this cannot be evaluated without knowledge of the existing situation in the respective

jurisdictions. Brief descriptions and evaluation criteria were then developed for each domain by reviewing

each domain’s encompassed indicators. Table 12 provides a summary of each domain and the reasoning

for their inclusion.

Table 12: A summary of the domains that were defined to evaluate the radiation protection legislation in RACT 2

Domain Description/ Reasoning for Inclusion

Clarity and

presentation of

legislative scope

The purpose of the document and its range of applications must be defined, such that the

measureable outcomes can be defined in the effective evaluation of the legislation [102].

Clarity allows the legislation to be fulfilled without interpretive difficulties, and so, target

users can organize their business accordingly and with confidence [105].

Transparency

Transparency refers to the description of open and understandable rules, procedures and

information [107]. The honesty and openness is important to minimizing corruption and

ensuring participation the targeted population (i.e. patients) [107]. This is expected to

improve substantive outcomes to radiation protection of patients.

Accountability

In good governance and effective legislation, accountability ensures that an organization

accounts for its activities, accepts responsibility and discloses the results [104]. There are

two types of accountability: vertical and horizontal. Vertical accountability ensures that

citizens remain informed, whereas horizontal accountability describes inter-department

adherence to standards [107].

Rigor of

compliance

requirements

Successful implementation of a legislation requires the policy initiatives to be delivered “in

accordance with expectations as to outcomes” [102]. Periodic review and supervision are

common strategies to measure the progress of legislation adoption [102]. Effective

legislation implementation allows for the standards to be met while minimizing the changes

to the already existing workflows.

Outcomes of non-

compliance

Enforceability of legislation by the courts provide a means for resistance to be easily

overcome and the desired results to be achieved. Oversight and enforcement can either be

presented as “punishment” for non-compliance or as a co-operative partnership between

citizens and officials [104]. Hence, the penalties enforcement powers, and court actions that

may be required should be analyzed and assessed for each legislation [106].

Fairness Impartiality is important when designing legislation, and so, the minimum level of

expectations should be the same for all institutions (e.g. public or private). The legislation

Page 83: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

62

should provide equitable processes such that all institution types have equal opportunity to

achieve compliance [101. Fairness should be evident in the presentation of the legislation

(e.g. language and vocabulary choice) [104]. This allows users to be confident in the

requirements and the governing authority.

5.2.3 Supplemental Documents Assessment

Supplemental documents in RACT 2 refer to any additional relevant publications in Table 5 that aim to

optimize the implementation of legislation by providing guidance for specific circumstances. These

documents are usually not legally binding and should “include recommendations that are informed by a

systematic review of evidence and provide an assessment of benefits and harms of alternative care

options” [109]. Most of the supplemental documents considered for analysis are clinical guidelines or

accreditation standards that are published by interested radiation protection organizations, with the aim of

providing validated advice on achieving compliance with the jurisdictional standards. Effective

supplemental document writing can overcome knowledge translation barriers, which allows the

documents to be easily implementable by targeted users.

5.2.3.1 Selection of Supplemental Document Domains

Two broad-based literature searches were required to identify suitable domains that are important in the

analysis of supplemental documents quality. The first literature search focused on understanding

knowledge translation barriers. Knowledge translation refers to the synthesis, exchange and application of

research evidence by relevant stakeholder to inform and improve healthcare systems and people’s health

[110]. In supplemental documents for radiation protection of medical exposures, effective knowledge

translation is beneficial because it closes the gap between the written recommendations and the reality of

clinical situations [111]. It ensures that validated action plans are being practised at the institutional level.

The results of the literature search revealed that the identified knowledge translation barriers in Landry et

al.’s article were comprehensive and generalized to encompass other specific barriers to adoption that are

commonly mentioned in other research articles (Table 13). The domains for supplemental document

assessment were selected to reflect critical attributes that if performed well would overcome Landry et

al.’s identified knowledge translation barriers.

Table 13: A summary of the common knowledge translation barriers identified in literature that obstructs the implementation of

new, validated recommended practices

Barrier Description Related constructs

Knowledge access

-Ability to learn of the existence of

knowledge and the ability to retrieve

it in a timely manner and useful form

-Lack of skills in knowledge management [111]

-Sheer volume of research (e.g. time

requirement to read and apply research) [111]

Page 84: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

63

-information overload [112] -Lack of time to understand knowledge [113]

Knowledge

incompleteness

-research knowledge is incomplete

-gaps between fundamental

relationships of causes and effects

[112]

-Lack of foreseeable benefits [113]

-Politics and power discrepancy (e.g. non-

consideration of research for the social

structure of the system) [114]

Knowledge

asymmetry

-a cognitive distance between the

sources of a given knowledge

transaction and its targets (i.e.

distance between knowledge “users”

and knowledge “producers” [112]

-professional-patient interaction barriers (e.g.

communication and information processing

issues) [115]

-Lack of integration with daily workflow [113]

-Separation between research ad health

communities [113]

-Difference in values and ideologies [114]

Knowledge valuation

-People exchange knowledge only

when the value gained by the parties

is greater than the involved costs

[112]

-Structural barriers (e.g. financial disincentives)

[115]

-Lack of financial resources [113], [114]

-Lack of peer support [113]

Knowledge

incompatibility

-When knowledge is incompatible

with their mission, historical context,

values, skills, resources, and prior

investments [112]

-Organizational barriers (e.g. lack of facilities or

equipment) [115]

-Professional barriers (e.g. different knowledge,

attitudes and skills) [115]

-Peer group barriers (e.g. difference in local

standards of care and desired practice) [115]

-inflexibility of knowledge [113]

-Lack of institutional support (e.g. time for

training and financial resource) [113]

The second broad-based literature search, therefore, was for articles that explain descriptive indicators for

the appraisal of guidance documents. Each article’s descriptive indicators were recorded, and the

collected data was treated as textual data. Articles were reviewed until there was an apparent saturation of

indicator descriptors. Saturation was defined as the point when additional articles did not reveal new

descriptors [103]. A general inductive method, as described in Section 5.2.1.1, was employed to recurring

constructs. The textual data were reviewed line by line and a code was assigned when a recurring theme

for the descriptive indicators became evident. Related indicators were grouped together for form an

overarching “domain”. After the formation of the domains, they were reviewed to determine whether

good performance in these domains could overcome the knowledge translation barriers described in Table

13. A summary of the domains, the related indicators that they encompass, and the knowledge translation

barrier they overcome are provided in Table 14.

Page 85: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

64

Table 14: A summary of the supplemental document assessment domains. The table provides an explanation of each domain, the related constructs used to form the domain as well

as a brief explanation of how knowledge translation barriers are overcome with strong performance within the domain.

Domain Description Encompassed constructs Counteracted knowledge translation barrier

Clarity of scope

and purpose

-Well-defined scope and purpose

will increase comprehension and

application by users since the

supplemental documents aim to

streamline practice changes to

meet new compliance standards

-Scope and purpose are clearly defined (e.g.

description of the rationale or reason for

development, goal or objective, topic or health

problem to be dealt with, practice setting, patient

population, intended users or audience) [97], [116],

[117], [118]

-Positive performance in this domain may help

overcome all of the knowledge translation

barriers because the scope and purpose of the

document must be defined in order to allow

accurate quality evaluation of the supplemental

document.

Evidence support

and explanation

for processes and

recommendations

-Evidence support is essential to

convince users of the need for

clinical practice changes. Action

plans should be validated by

improved health outcomes in

research studies before their

widespread recommendations to

facilities.

-Rigor of development refers to the process used to

gather and synthesize the evidence, the methods to

formulate the recommendations [97], [117]

-Apparent validity: degree to which the

recommendations reflect the strength of evidence

[96]

-Clinical relevance and appropriateness of

recommendations for patient population [119]

-Significance and ratings of scientific evidence

relevance [118], [120]

-Information retrieval: criteria to include and

exclude literature in making recommendations

[116]

-Positive performance in this domain may

overcome the knowledge asymmetry barrier.

Substantial evidence of the recommendations’

success in a specific clinical setting will increase

confidence amongst the intended users, and

should improve adoption of the

recommendations.

-This domain’s performance should also affect the

knowledge valuation barrier. If the development

of the article is justified, then the benefits of the

recommendations will be obvious and the

knowledge will be valued.

Instructive quality

of writing

-Actionable recommendations

require clear and detailed

descriptions of the processes and

recommendations. High

accessibility of the document will

also increase the actionability of the

supplemental document.

-Presentation and formatting: degree to which the

recommendation is easily recognizable [96], [116]

-Clarity of presentation: concrete and precise

descriptions [97], [118]

-Format: easy to follow document for end users

with logical layout and visual information [119]

-Easy to understand vocabulary [116]

-A high score in this domain should overcome the

knowledge incompleteness barrier. Precise and

concrete descriptions for the recommended

action plans should close the gap between the

cause and effects relationships that users may

have.

Page 86: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

65

Adaptability -There are two dimensions to this

domain. Firstly, a wide range of

foreseeable clinical situations

should have a concrete and precise

recommended action plans.

Secondly, the recommendations

should permit for interpretation as

the workflows are expected to vary

between facilities.

-Decidability: precisely under what conditions to do

something [96]

-Executability: exactly what to do under the

circumstances is defined [96]

-Flexibility and adaptability: degree to which a

recommendation permits interpretation and allows

for alternatives in its execution [96], [97], [116]

-implementation feasibility: availability of resources

and application using various levels of available

resources [119]

-Range of situations: provides available preventive,

diagnostic or therapeutic options to targeted users

[117]

-This domain counteracts the knowledge

incompatibility barrier. While the barrier cites

resistance to recommendations due to

differences in ideology and resources between

researchers and users [112], flexible and

adaptable recommendations should allow for

sufficient interpretation amongst users from

different institution types.

Integration of

inter-professional

perspectives

-There are many stakeholders

involved in CT dose management.

The needs and priorities of each

stakeholder group should be

represented and considered in the

suggested recommendations of the

document. This will increase the

credibility of the document among

intended user groups.

-Stakeholder involvement: the extent to which the

guideline was developed by the appropriate

stakeholders and represents the views of intended

users [97]

-Credibility of guideline development group

dependent on members’ technical backgrounds

and transparency [119]

-Consideration of different perspectives: discussion

within document regarding various stakeholders’

and their influences on the recommendations [116]

-Evaluation of expert opinions [116]

-Reliability: external peer review before publication

or pilots testing of guideline prior to release [116],

[117]

-Independence: not under the influence of funding

-This domain is expected to influence the

knowledge valuation and knowledge asymmetry

barriers. The valuation of knowledge will be

increased since the different stakeholders will

focus on the needs and priorities of the users

involved in the clinical processes. This should

provide evidence to the validity and benefits of

the recommendations. Secondly, the distance

between researchers and users will be closer

because the involvement of all stakeholders

presents an accurate depiction of the clinical

situation where all stakeholder are also involved.

Page 87: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

66

group and no conflicts of interest [97], [116]

Rigor of

expectations

-The amount of work that is

required to achieve compliance

with the new legal standards.

Depending on the standards,

expectations may require a change

in social infrastructure,

organizational culture, and/or

jurisdictional commitment.

-Measureable outcomes: degree to which the

document identifies endpoints to track the effects

of implementation [96]

-Effects on process of care: degree to which

recommendation impacts upon the usual workflow

of a care setting [96]

-Application: required adaptation and changes to

resources to achieve recommended care processes

[118]

-Health outcomes and effects: cost-benefit analysis

of the recommendations to determine effects on

the workflows [117], [119]

-In considering the costs and benefits to the

recommendations, more complete knowledge

can be gained. This will have an effect on the

knowledge incompleteness barrier.

-Secondly, this domain is expected to affect the

knowledge valuation because the benefits and

values to the new recommendations will be

evident.

Rigor of updates -Recommendations may become

non-applicable as new technology

and research results emerge. It is

important to ensure that the

information within a document is

regularly reviewed and updated to

maintain its validity. This will

increase confidence amongst

intended users.

-Currentness: how often guidelines are updated,

validity of the information, and procedure for

updating the document [116]

-Validity of recommendations: recommendations

are graded according to strength of evidence and

specific to the stated goals of the document [116],

[117]

-If this domain is performed well by a document,

then the knowledge access barrier should be

negated. Time is wasted due to the sheer volumes

of research regarding a topic, and users have to

decipher the useful information. However,

current and validated recommendations within a

document will strengthen the confidence of

users.

Page 88: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

67

5.3 Structure of RACT 2

The final RACT 2 design is detailed in Appendix E. This section provides a brief explanatory outline of

the instrument and its intended application. Evaluations of jurisdictions using RACT 2 should ideally

involve a minimum of two reviewers. This increases the reliability of the results. RACT 2 is divided into

three separate parts: comprehensiveness checklist, legislation assessment and supplemental document

assessment. The latter two parts have similar outlines and are intended to be used in a similar manner.

Limitations inherent to the design of RACT 2 are also discussed.

5.3.1 Application of RACT 2’s Comprehensiveness Checklist

The comprehensiveness checklist was designed as a quantitative evaluation for each regulatory model.

The same type of documents (i.e. legislative or supplemental) can be combined for analysis. It should be

used as a binary checklist, which suggests that the rater should simply identify whether or not the key

item was included in the reviewed document. There are descriptions provided in the sub-themes to further

explain the concept that is being reviewed. For example, the sub-theme of “Administrative responsible

person” under the theme of “Personnel Requirements” has the description “This is the person who is

legally liable for a given radiological installation (e.g. employer, license holder, owner).” The quality of

each item will be assessed in the later parts of RACT 2.

Due to the use of quantitative measures, the inter-rater reliability should be 1.00 since the checklist of

items was designed to not be subject to interpretation. However, if there is discrepancy, the inter-rater

reliability should be calculated using percentage agreement, which is simply the number of times the

raters agree divided by the sum of items [121]. Inter-rater reliability should be calculated for each theme,

as well as for the aggregated sum. If the inter-rater reliability is below 90%, a discussion should be held to

propose clarifications on the areas of confusion [121]. Final scores for each theme should be proposed

through discussion and consensus once inter-rater reliability is satisfactory. The number of items that

have been fulfilled in each theme should be summed, and the percentage of fulfillment for each theme and

the aggregate sum should be calculated to facilitate cross-jurisdictional comparisons.

5.3.2 Application of RACT 2’s Legislative and Supplemental Documents

Assessment

The legislative and supplemental documents assessment parts in RACT 2 should be used in a similar

manner. Again, all the legislative documents and all the supplemental documents for a jurisdiction can be

combined for analysis. For each domain, a brief description is provided to explain the rationale for the

domain and its importance in the quality of the document evaluation. Then, key considerations are

Page 89: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

68

provided to guide the judgement of the rater and they identify explicit elements that should be in

accordance with the description of the domain.

A domain may be evaluated for several different criteria, where each criterion has its own rating scale.

The rating scale employed is a 5-point Likert Scale, which is an ordinal level of measurement used to

qualitatively score a domain. This type of measurement is limited by the required subjectivity of the rater,

which is why additional information is provided to explain each score on the rating scale. This

information is not intended to offer absolute standards for scoring, but rather, help facilitate the user’s

assessment. It is recommended that the Comments section be completed for each domain to facilitate

inter-rater discussions between evaluation rounds if required.

Each document should be scored individually for each criterion, and then an average score should be

given. An overall domain score should be provided after consideration of all individual criteria scores.

When the independent evaluations by each reviewer is complete, the inter-rater reliability should be

calculated to ensure reproducibility of the assessment results. The weighted Cohen’s κ for each domain,

and 95% confidence interval that the agreement is better than chance should be calculated. Weighted

Cohen’s Kappa is designed to be used with ordinal data such as Likert Scales because it accounts for

partial agreement, which is useful for inter-rater reliability [122]. The Fleiss Benchmark Scale should be

used to evaluate the level of agreement; where κ values <0.40, 0.40 to 0.75, and >0.75 represent poor,

intermediate to good and excellent agreement, respectively [123]. Interim discussions and subsequent

evaluation rounds should be conducted until inter-rater reliability reaches a satisfactory aggregated

weighted Cohen’s κ > 0.75. Once κ is satisfactory, final scores for each domain should be achieved

through discussion and consensus amongst reviewers.

5.3.3 Potential Limitations of RACT 2

Due to the design process of RACT 2 that used the specific documents in Table 5 to generate the

comprehensiveness checklist, the key items of Part 1 of RACT 2 may not be applicable to all

jurisdictional models. However, the large sample size of radiation protection in medical exposure

documents is expected to cover the majority of the possible regulatory approaches to CT radiation dose

management based on current knowledge. The key items documented the unique approach each

jurisdiction has taken to fulfill the sub-themes and is expected to be variable between jurisdictions, but the

sub-themes and themes should remain consistent across jurisdictional models. There was a saturation of

themes and sub-themes in the thematic analysis applied to generate the comprehensiveness checklist,

Page 90: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

69

which is defined as the point where additional documents did not raise new recurring concepts [103]. The

potential limitation to RACT 2 is, therefore, restricted to the key items checklist.

The other potential limitation of RACT 2 is the use of qualitative measurements to evaluate the quality

and implementability of the documents. Since Likert scale measurements require the subjectivity of the

rater, the inter-rater reliability tend to be lower in these evaluations. To counteract this potential

limitation, the evaluative criteria are provided with detailed descriptions of each Likert Scale score. This

is expected to guide the judgement of the raters and to increase inter-rater reliability. The intended use of

RACT 2 also lessens the potential limitation of qualitative measurements. Furthermore, RACT 2 is not

designed to provide absolute scores for each jurisdiction, but rather, the ordinal levels of measurement

can be used to distinguish an inter-jurisdictional rank order for each domain to provide a systematic

comparison of each jurisdictional model.

5.4 Summary of Assessment Framework Development

An assessment framework (RACT 2) for the systematic evaluation of CT radiation protection regulatory

structures was designed. A pilot study (RACT 1) using six preliminary jurisdictions was conducted to

elicit the factors that influence the practicality of the assessment instrument. RACT 2 was designed to

include three different parts: comprehensiveness checklist, legislative document assessment and

supplemental document assessment. The comprehensiveness checklist employs quantitative measures to

maximize inter-rater reliability. The legislative document and supplemental document assessments

employ 5-point Likert Scale measurements for each domain. Domains for the legislative document

assessment were selected to reflect indicators that influence the quality of legislation, whereas domains

for the supplemental document assessment were selected to encompass related constructs that are

predicted to overcome common knowledge translation barriers. There are potential limitations to the

design of the final assessment instrument, but measures have been taken to minimize the impact of these

potential limitations.

Page 91: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

70

6 Evaluation of Jurisdictional CT Dose Management

Models

The third objective was to evaluate the selected jurisdictional radiation protection publications for overall

quality and implementability, as well as assess the dose levels in each jurisdiction. The results of the

analyses generated a high-level understanding of the relationship between regulatory approaches and dose

trends. Through the results of evaluation using RACT 2 and the interviews with jurisdictional

representatives in Chapter 4, elements that positively impact implementation of CT dose management

regulations were identified and discussed. Limitations of this analysis will also be described.

6.1 Evaluation of Radiation Publication Documents using RACT 2

The intended regulatory structure for CT dose management can be interpreted from the radiation

protection publications for each jurisdiction. The relevant publications as identified in Table 5 were

reviewed and analyzed using RACT 2. Due to the limited resources, only one reviewer was available to

evaluate the jurisdictional documentations. This eliminated the opportunity to evaluate the reliability and

reproducibility of results using RACT 2, but this analysis method still successfully identified elements

that are predictive of effectiveness and implementability. Cross-jurisdictional comparisons of the

comprehensiveness of each document were performed to identify elements that were recurring in the

intended regulatory approaches for each jurisdiction. Japan was excluded from the RACT 2 assessments

because the jurisdiction did not have any relevant radiation protection publications that include standards

for CT operation. Domain score analyses for the legislative and supplemental documents assessment were

analyzed to identify consistent attributes in document writing that may be predictive of effectiveness. A

high-level understanding of the relationship between dose trends and key elements in the regulatory

structures of select jurisdictions was also obtained.

6.1.1 Comprehensiveness Assessment

The comprehensiveness assessment was divided into two parts. Firstly, the legislative documents from

each jurisdiction were combined together for the checklist. These documents are highlighted using red

font in Table 5. Then, the supplemental documents (highlighted with green font in Table 5) for each

jurisdiction were combined and analyzed for comprehensiveness using the checklist. British Columbia’s

Diagnostic Accreditation Program (DAP) Standards were analyzed as both a legislative and supplemental

document because of its strict classification of “mandatory requirement for accreditation” and

recommended actions. For the analysis, mandatory requirements were reviewed as legislative since BC’s

Page 92: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

71

DAP is governed by a sub-committee appointed by the College of Physicians and Surgeons of British

Columbia (CPSBC). As a part of CPSBC, the DAP accreditation standards are bound by the province’s

Health Professions Act that is designed to lend legal powers to health profession associations [124].

Relevant recommended actions were then reviewed as “supplemental”.

6.1.1.1 Legislative Documents Comprehensiveness

The number of items fulfilled per theme by each jurisdiction is displayed in Figure 17. Additionally,

Figure 17 also displays the total number of items per theme for comparison purposes. Texas has

comparatively fulfilled the most requirements overall despite providing information for only 161 of the

322 (i.e. 50%) possible items. California’s legislation provides the least detail in its radiation protection

by fulfilling only 43 of the 322 items. Ontario’s legislation ranks among the lower end of fulfillment with

information for 68 items, and is within the same range as developing countries like Kenya and India.

Ireland is the other developed jurisdiction that is also within the lower range, providing information for 68

of 322 items.

Figure 17: The number of items fulfilled by each jurisdiction for each theme. Texas fulfilled the highest number of items despite

only fulfilling half of the total possible number of items.

0

50

100

150

200

250

300

350

Nu

mb

er o

f It

ems

Jurisdiction

General Provisions Reponsible Authorities

Licensing and Accreditation Technical Requirements

Facility Requirements Operational Requirements

Personnel Requirements Radiation Protection/Quality Assurance Committee

Patient Records and Patient Medical Reports Emergency Situations and Event Reporting

Diagnostic Reference Levels Results of non compliance

Page 93: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

72

A more detailed breakdown of the percentage fulfillment (i.e. number of items fulfilled in a theme divided

by the total number of items in a theme) for each jurisdiction is presented in the heat map display in

Figure 18a. The heat map provides visualization of the percentage fulfillment and elicits patterns in the

data. It employs a graded colour scale of red to green to describe the percentage fulfillment: red indicates

low percentage fulfillment and green indicates high percentage fulfillment. The colour scale is normalized

to the lowest and highest value in the data matrix, and so, the darkest shades of red and green are

employed for 0.00% and 85.71% of fulfillment (Portugal’s general provisions score), respectively. The

approximate percentage values that correspond to each colour is displayed in Figure 18b.

The results of the percentage fulfillment by theme in Figure 18 shows that the general provisions theme is

the highest overall scoring theme, with 10 of the 13 jurisdictions fulfilling over 50% of the items in this

theme and the lowest percentage fulfillment was 28.57%. Furthermore, the general provisions theme had

an average percentage fulfillment of 56.04%. The lowest scoring theme was diagnostic reference levels.

The average percentage fulfillment of this theme was 18.97%, with four of the 13 jurisdictions not

providing any information about the DRLs. Each jurisdiction also provided information regarding at least

one key item in the following themes: responsible authorities, licensing and accreditation, operational

requirements and personnel requirements.

Page 94: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

73

(a)

Theme Total General Provisions

Responsible Authorities

Licensing and Accreditation

Technical Requirements

Facility Requirements

Operational Requirements

Personnel Requirements

Radiation Protection/ Quality Assurance Committee

Patient Records and Patient Medical Reports

Emergency Situations and Event Reporting

Diagnostic Reference Levels

Results of non- compliance

Australia 30.12% 71.43% 40.54% 41.38% 22.86% 18.75% 30.00% 16.67% 27.27% 18.18% 26.67% 13.33% 52.17%

British Columbia

31.06% 71.43% 8.11% 13.79% 51.43% 50.00% 35.71% 40.48% 40.91% 45.45% 26.67% 13.33% 0.00%

California 13.35% 28.57% 21.62% 41.38% 2.86% 0.00% 7.14% 2.38% 0.00% 36.36% 26.67% 0.00% 26.09%

Eurotam 34.47% 85.71% 27.03% 10.34% 34.29% 43.75% 38.57% 47.62% 22.73% 27.27% 66.67% 46.67% 4.35%

Germany 30.75% 42.86% 21.62% 24.14% 45.71% 68.75% 18.57% 47.62% 36.36% 45.45% 0.00% 33.33% 13.04%

Ireland 20.81% 28.57% 16.22% 3.45% 37.14% 0.00% 25.71% 23.81% 31.82% 18.18% 0.00% 26.67% 17.39%

India 18.01% 57.14% 10.81% 44.83% 17.14% 31.25% 15.71% 16.67% 0.00% 0.00% 33.33% 0.00% 13.04%

Kenya 18.32% 57.14% 18.92% 55.17% 0.00% 43.75% 12.86% 16.67% 4.55% 9.09% 0.00% 0.00% 30.43%

Ontario 21.12% 28.57% 16.22% 48.28% 34.29% 18.75% 11.43% 26.19% 0.00% 0.00% 20.00% 0.00% 39.13%

Portugal 32.30% 85.71% 27.03% 44.83% 25.71% 25.00% 38.57% 35.71% 31.82% 18.18% 20.00% 13.33% 26.09%

Switzerland 31.99% 57.14% 43.24% 48.28% 20.00% 37.50% 17.14% 33.33% 27.27% 18.18% 53.33% 46.67% 30.43%

Texas 50.00% 57.14% 75.68% 75.86% 57.14% 31.25% 40.00% 28.57% 36.36% 27.27% 66.67% 20.00% 78.26%

UK 29.50% 57.14% 8.11% 31.03% 34.29% 43.75% 32.86% 35.71% 27.27% 18.18% 33.33% 33.33% 17.39%

Average 56.04% 25.78% 37.14% 29.45% 31.73% 24.95% 28.57% 22.03% 21.68% 28.72% 18.97% 26.76%

(b)

Figure 18 (a) A heat map display to provide visualization of the percentage fulfillment of each theme by every jurisdiction. The data is normalized to the lowest and highest percentage fulfillment in

the data (0.00% and 85.71%, respectively). (b) The breakdown of the graded colour scale used for the heat map. Red indicates low percentage fulfillment and green represents high percentage

fulfillment.

Page 95: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

74

Another informative method of comparing the content in the radiation protection legislation for each

jurisdiction is a comparison of sub-theme fulfillment. As discussed in Section 5.3.3, each jurisdiction’s

approach to implementing radiation protection efforts is likely to be different. The key items in the

checklist is summative of all the possible approaches undertaken in every jurisdiction, but the sub-themes

were developed using a general inductive approach to identify recurring concepts in the legislative

documents from different jurisdictions.

Table 15 displays a fulfillment checklist for each sub-theme. A jurisdiction is provided with a

“checkmark” if it has provided information in its legislation for at least one item in each sub-theme. Each

jurisdiction has provided information about the general provisions (e.g. scope and purpose of document)

and the highest responsible authority. Furthermore, 12 of 13 jurisdictions have legal clauses regarding the

basic general standards for licensing and accreditation of facilities with ionizing radiation equipment and

recordkeeping requirements for technical standards. These sub-themes are likely to be important in the

regulatory structures to CT dose management in different jurisdictions. On the other hand, only 1 of 13

jurisdictions provided specific clauses to explain the delegation of medical acts, the sharing of patient

records and different severity levels in non-compliance. These clauses are expected to be important to

select jurisdictions because of the healthcare system structure.

General trends in the data matrix in Table 15 shows that Texas, Switzerland, Portugal and Germany have

a fairly event spread of sub-theme fulfillment. However, the jurisdiction that has the lowest number of

items fulfilled (i.e. California) addresses 19 of the sub-themes. California does not address the

establishment of radiation protection/ quality assurance committees. Furthermore, California only

addresses one sub-theme in each of operational requirements and personnel requirements. Ontario ranks

the same as India and Kenya, two developing countries, in sub-theme fulfillment. Each of the three

jurisdictions provides information for 24 sub-themes in the comprehensiveness checklist.

Page 96: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

75

Table 15: A sub-theme fulfillment checklist. Jurisdictions that address at least one of the key items in a sub-theme are marked with an "x".

Theme Sub-Theme AU BC CA EU DE IL IN KN ON PR SW TX UK No. of

Jurisdictions

General Provisions

x x x x x x x x x x x x x 13

Responsible Authority

Highest responsible authority x x x x x x x x x x x x x 13

Supervisory Authority x x x x x x 6 Other Sub-councils for Radiation Health and Safety

x x 2

Financial Matters x x x 3

Miscellaneous x x x x x x x 7

Licensing and Accreditation

Basic general standards x x x x x x x x x x x x 12

Application Process x x x x x x x x x x x 11 Decision-making procedure of licensing authority

x x x x x x x x 8

Appeal of licensing decisions x x x x x x 6 Modification, transfer, revoking or suspension of a license

x x x x x x x x x 9

Miscellaneous x x x x x x x x 8

Technical Requirements

New installation x x x x x x x x x x 10

Maintenance and Repairs x x x x x x x x x x x 11

Quality Control Testing x x x x x x x 7 Calibration and dosimetry equipment x x x 3

Recordkeeping requirements x x x x x x x x x x x x 12

Miscellaneous x x x x x 5

Facility Requirements

Specified areas (e.g. supervised area, controlled area, uncontrolled area)

x x x x x x x x 8

Facility layout x x x x x x x x x x x 11

Operational Requirements

Inspection by supervisory authority x x x x x x x x x x x 11

Internal clinical audits x x x 3

Page 97: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

76

Theme Sub-Theme AU BC CA EU DE IL IN KN ON PR SW TX UK No. of

Jurisdictions

Operational Requirements

Clinical justification for medical radiation exposure x x x x x x x x x 9

Referral process x x x x x x x 7 “As low as reasonably achievable” (ALARA) approach to radiation exposure

x- x x x x x x x x x x 11

Standard clinical protocols for routine scans

x x x x x x x x 8

Delivery of ionizing radiation x x x x x x x x 8

Special populations x x x x x x x 7

Systems to file complaints x x 2

Delegation of Medical Acts x 1

“New” Procedures x x x x x 5

Miscellaneous x x x x x x x x 8

Personnel Requirements

Administrative Responsible Person x x x x x x x x x x 10

Designated responsible user x x x 3 Radiation Protection Supervisor x x x 3 Radiation Protection Officer/ Radiation Safety Officer

x x x x x x x 7

Qualified technical expert (e.g. medical physicist)

x x x x x x x x 8

Persons responsible for the radiation exposure (e.g. medical practitioner)

x x x x x x x x x x x

11 Persons authorized to prescribe/refer scans

x x x x x 5 Persons authorized to operate CT scanner

x x x x x x x 7 Persons to assemble, install or repair a CT scanner

x x x 3 Training programs and continuing education

x x x x x x x x x x x 11

Page 98: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

77

Theme Sub-Theme AU BC CA EU DE IL IN KN ON PR SW TX UK No. of

Jurisdictions Personnel

Requirements (continued)

Recordkeeping Requirements x x x x x x x x x 9

Miscellaneous x x x x x x 6

Radiation Protection

Committee or Quality

Assurance Committee

Committee set-up x x x x x x x x x 9

Committee meetings x x x x x x x 7 Accountability to responsible/supervisory committee

x x x x x x 6

Patient Records and Patient

Medical Records Patient record requirements

x x x x x x x x x x x 11

Sharing of patient records x 1

Emergency Situations and

Event Reporting

Institutional requirements for emergency radiation incident situations

x x x x x x x x 8

Reporting requirements to the supervisory authority

x x x x x x x x x 9

Notification Requirements x x x x x x 6

Diagnostic reference levels

Institutional diagnostic reference levels x x x x x x x x x 9 Official jurisdictional diagnostic reference levels

x x x x x x x 7

Accountability with DRLs x x x x 4

Results of Non-compliance

General Non-compliance standards x x x x x x x x x x 10

Criminal provisions x x x x x x x x 8

Monetary penalties x x x x x x x 7

Severity levels x 1 Seizure or forfeiture of property x x x x x 5

License Violations x x x x x x x x x 9

Total 37 35 19 39 40 33 24 24 24 42 44 46 38

Page 99: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

78

6.1.1.2 Supplemental Documents Comprehensiveness

The documents highlighted with green font in Table 5 were used to conduct the comprehensiveness

assessment for the supplemental documents, which are defined as non-legally binding documents that are

used to optimize implementation of a jurisdiction’s legal standards. Similar analyses as those mentioned

in Section 6.1.1.1 for the radiation protection legislations were performed. Figure 19 provides a visual

display of the number of items in each theme that was fulfilled by every jurisdiction’s supplemental

documents. IAEA’s Basic Safety Standards fulfills the most number of items, providing information for

117 of the 322 possible items. The Medical Council of Ireland’s position paper focuses on DRLs, and so,

it fulfills the least number of items (7 of 322). The majority of British Columbia’s diagnostic accreditation

program standards are mandatory and was analyzed as legislation, so its fulfillment of items as a

supplemental document was very low at 10 of 322 items. Canada was analyzed as a separate jurisdiction

because the parts of Safety Code 35 that were deemed pertinent to BC standards were extracted and put

into the BC DAP accreditation document. The other Canadian province available in the analysis, Ontario,

does not actively recommend Health Canada’s Safety Code 35 to CT facilities and so, the Safety Code

was not considered as a supplemental document for Ontario in this assessment.

Figure 19: A visual display to show the number of items fulfilled for each theme for every jurisdiction. IAEA’s Basic Safety

Standards comparatively fulfilled the most number of items.

The heat map display in Figure 20a provides a further breakdown of the percentage fulfillment for each

theme by every jurisdiction. The graded colour scale of red to green provides visualization of the

percentage fulfillment, with red indicating low fulfillment and green indicating high fulfillment. The

colour scale has been normalized to the lower and highest value in the dataset, which is 0.00% and

0

100

200

300

Australia BC Canada California IAEA Ireland India UK Total No.of ItemsGeneral Provisions Reponsible Authorities

Licensing and Accreditation Technical RequirementsFacility Requirements Operational RequirementsPersonnel Requirements Radiation Protection/Quality Assurance CommitteePatient Records and Patient Medical Reports Emergency Situations and Event Reporting

Page 100: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

79

100.00% respectively. The percentage fulfillment values that correspond to the different colours in the

heat map are approximated in Figure 20b.

In reviewing the thematic percentage fulfillment of each jurisdiction, the general provisions theme has the

highest percentage fulfillment at 44.64% and is closely followed by technical requirements (34.64%) and

diagnostic reference levels (34.17%). Health Canada’s Safety Code 35 also has a perfect fulfillment score

of 100.00% for general provisions, which suggests it provided a detailed explanation of the document

including the scope of application, purpose, and explained the development of the document. Each of the

themes have an average percentage fulfillment of greater than 15%, with the exception of the three lowest

scoring themes (i.e. responsible authorities, licensing and accreditation, and results of non-compliance).

The three lowest scoring themes address the authorities and powers of each document, which are

inapplicable to supplemental documents. Supplemental documents do not have any legal authority as a

standalone document, and are designed to optimize the implementation of a jurisdiction’s legal standards

by providing detailed information about recommended radiation protection action plans.

The sub-theme fulfillment analysis is displayed in Table 16. A jurisdiction is provided with an “x” when

its documents have provided information for at least one of the key items listed in the sub-theme. None of

the sub-themes have fulfillment from all of the eight jurisdictions with supplemental documents. Seven of

eight jurisdictions have information in the jurisdictional supplemental documents for the sub-themes of

training programs and continuing education in the personnel requirements and committee set-up in the

radiation protection/quality assurance committee theme. The attention that the jurisdictions paid these

sub-themes indicate their importance in the regulatory approaches to CT dose management in different

jurisdictions.

Contrastingly, there are many sub-themes that have not been addressed by any of the jurisdictions. They

include sub-councils for radiation health and safety and financial matters under the responsible authorities

theme, appeal of licensing decisions and modification, transfer, revoking or suspension of licenses under

the licensing and accreditation theme, delegation of medical acts under operational requirements and four

of the six sub-themes under results of non-compliance. These sub-themes are important in the

establishment of standards, which does not have applicability in supplemental documents. General trends

in Table 16 show that the IAEA has the most even distribution of fulfillment of sub-themes (i.e. 43 sub-

themes). Ireland’s DRL focused document, on the other hand, only fulfills two sub-themes, with both of

them being in the Diagnostic Reference Levels theme.

Page 101: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

80

(a)

(b)

Theme Total General

Provisions Responsible Authorities

Licensing and Accreditation

Technical Requirements

Facility Requirements

Operational Requirements

Personnel Requirements

Radiation Protection/

Quality Assurance Committee

Patient Records

and Patient Medical Reports

Emergency Situations and Event Reporting

Diagnostic Reference

Levels

Results of non-

compliance

Australia 28.26% 71.43% 0.00% 0.00% 45.71% 31.25% 35.71% 38.10% 31.82% 27.27% 40.00% 53.33% 0.00%

BC 3.11% 0.00% 0.00% 0.00% 0.00% 6.25% 2.86% 2.38% 18.18% 0.00% 13.33% 0.00% 0.00%

Canada 26.71% 100.00% 0.00% 6.90% 57.14% 43.75% 28.57% 42.86% 22.73% 9.09% 0.00% 40.00% 0.00%

California 25.47% 28.57% 0.00% 6.90% 51.43% 37.50% 25.71% 35.71% 45.45% 45.45% 13.33% 26.67% 0.00%

IAEA 36.34% 71.43% 18.92% 13.79% 45.71% 0.00% 41.43% 54.76% 36.36% 27.27% 60.00% 66.67% 13.04%

Ireland 2.17% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 46.67% 0.00%

India 9.94% 42.86% 0.00% 0.00% 5.71% 25.00% 15.71% 16.67% 22.73% 0.00% 0.00% 0.00% 0.00%

UK 24.84% 42.86% 0.00% 3.45% 71.43% 12.50% 17.14% 30.95% 31.82% 18.18% 60.00% 40.00% 0.00%

Average 19.60% 44.64% 2.36% 3.88% 34.64% 19.53% 20.89% 27.68% 26.14% 15.91% 23.33% 34.17% 1.63%

Figure 20: A heat map display for the percentage fulfillment of each theme for every jurisdiction with supplemental documents. The colour scale is normalized to the lowest and highest value of the

dataset, which are 0.00% and 100.00%. (b) The breakdown of the graded colour scale used for the heat map. Red indicates low percentage fulfillment and green represents high percentage fulfillment

Page 102: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

81

Table 16: A summary of the sub-theme fulfillment. Jurisdictions that address at least one key item in each sub-theme is awarded with an "x" in that specific sub-theme.

Theme Sub-Theme Australia BC Canada California IAEA Ireland India UK No. of

Jurisdictions

General Provisions

x x x x x x 6

Responsible Authority

Highest responsible authority x 1

Supervisory Authority x 1

Other Sub-councils for Radiation Health and Safety

0

Financial Matters 0

Miscellaneous x 1

Licensing and Accreditation

Basic general standards x x 2

Application Process x 1

Decision-making procedure of licensing authority

x 1

Appeal of licensing decisions 0

Modification, transfer, revoking or suspension of a license

0

Miscellaneous x x 2

Technical Requirements

New installation x x x x x 5

Maintenance and Repairs x x x x x x 6

Quality Control Testing x x x x 4

Calibration and dosimetry equipment x 1

Recordkeeping requirements x x x x x x 6

Miscellaneous x x x x x 5

Facility Requirements

Specified areas (e.g. supervised area, controlled area, uncontrolled area)

x x x 3

Facility layout x x x x x x 6

Operational Requirements

Inspection by supervisory authority x x x 3

Internal clinical audits x x x 3

Page 103: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

82

Theme Sub-Theme Australia BC Canada California IAEA Ireland India UK No. of

Jurisdictions

Operational Requirements

Clinical justification for medical radiation exposure

x x x x x x 6

Referral process x x x x 4

“As low as reasonably achievable” (ALARA) approach to radiation exposure

x x x x x x 6

Standard clinical protocols for routine scans

x x x x 4

Delivery of ionizing radiation x x x x 4

Special populations x x x x 4

Systems to file complaints x 1

Delegation of Medical Acts 0

“New” Procedures x x x 3

Miscellaneous x x x x x x 6

Personnel Requirements

Administrative Responsible Person x x x x x 5

Designated responsible user x x x 3

Technical Director x 1

Radiation Protection Supervisor x 1

Radiation Protection Officer/ Radiation Safety Officer

x x x x 4

Qualified technical expert (e.g. medical physicist)

x x x x x 5

Persons responsible for the radiation exposure (e.g. medical practitioner)

x x x x 4

Persons authorized to prescribe/refer scans

x x x 3

Persons authorized to operate CT scanner

x x x x 4

Page 104: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

83

Theme Sub-Theme Australia BC Canada California IAEA Ireland India UK No. of

Jurisdictions

Personnel Requirements

(continued)

Persons to assemble, install or repair a CT scanner

x x x 3

Training programs and continuing education

x x x x x x x 7

Recordkeeping Requirements x x x x 4

Miscellaneous x x x 3

Radiation Protection

Committee or Quality Assurance

Committee

Committee set-up x x x x x x x 7

Committee meetings x x x 3

Accountability to responsible/supervisory committee

x x 2

Patient Records and Patient

Medical Records

Patient record requirements x x x x x 5

Sharing of patient records x 1

Emergency Situations and

Event Reporting

Institutional requirements for emergency radiation incident situations

x x x x x 5

Reporting requirements to the supervisory authority

x x x 3

Notification Requirements x x 2

Diagnostic reference levels

Institutional diagnostic reference levels x x x x x x 6

Official jurisdictional diagnostic reference levels

x x x x 4

Accountability with DRLs x 1

Results of Non-compliance

General Non-compliance standards x 1

Criminal provisions 0

Monetary penalties 0

Severity levels 0

Seizure or forfeiture of property 0

License Violations x 1

Total 28 6 30 30 43 2 17 27

Page 105: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

84

6.1.2 Legislation Quality Assessment

A reviewer evaluated each jurisdiction’s legislations against the domains in RACT 2 using a Likert Scale

from 0 to 4, with 0 being the lowest possible score. The detailed evaluations, with comments, for each

criterion within the domains are provided in Appendix F. Figure 20 provides a heat map breakdown of the

domain scores for every jurisdiction’s legislative documents. The graded colour scale of red to green is

used to indicate the quality of each jurisdiction’s fulfillment of the domain. Each of the colours in the

scale correspond to the Likert Scale rating as follows:

Red = 0 = extremely poor

Orange = 1 = below average

Yellow = 2 = acceptable

Light green = 3 = good

Dark green = 4 = excellent

Domain AU BC CA EU DE IE IN KN ON PR CH TX UK Avg

Clarity and Presentation of Legislative Scope

3 4 2 4 2 4 3 2 2 3 4 3 4 3.1

Transparency 2 3 1 3 1 1 1 1 1 3 4 3 2 2.0

Accountability 2 2 2 2 2 2 1 2 3 3 4 4 2 2.4

Rigor of Compliance Requirements

1 2 2 3 2 2 1 1 1 3 3 4 1 2.0

Outcomes of non-compliance

0 2 3 N/A 4 2 1 3 3 3 4 3 2 2.5

Fairness 2 4 2 2 3 3 2 2 2 1 2 4 2 2.4

Average 1.4 2.6 2 2.5 2.4 2 1.2 1.8 2 2.6 3.4 3.6 1.8

Figure 21: A heat map display to show the domain score for every jurisdiction in the legislative quality. The highest scoring

domain on average is clarity of legislative scope, with an average score of 3.1. The highest scoring jurisdiction, on average, is

Texas with an average domain score of 3.6.

In a comparison across the domain scores in Figure 20, the highest scoring domain is the clarity and

presentation of legislative scope with an average of 3.1. None of the jurisdictions scored below a 2 in this

domain. Contrastingly, the two lowest scoring domains are transparency and rigor of compliance

requirements, with each of the domains averaging scores of 2.0. Six of the eight jurisdictions scored

below average in the transparency domain, whereas five jurisdictions scored below average in the rigor of

compliance requirements domain. The only 0 assigned was for Australia’s outcomes of non-compliance

score. The Australian legislations did not provide information regarding the consequences to CT facilities

if the standards are not achieved. Euratom’s Council Directives were not assigned a score for the

Page 106: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

85

outcomes of non-compliance because it acts as an international legal person, and does not have direct

jurisdiction over any of its member states. Hence, the consequences to non-compliance should be adapted

to each member state’s legal system.

Texas has the highest score (i.e. 3.6) for its legislative quality, with scores indicating of at least 3 for each

of the domains. The lowest quality average score across domains is 1.2 for India’s legislations who scored

below average in transparency, accountability, rigor of compliance requirements and outcomes of non-

compliance. Ontario, with score of 2, ranks among the lower end in terms of legislative documents

quality. Ontario did not score the highest possible score of 4 in any of the domains, but it did score below

average in both transparency and rigor of compliance requirements.

Polar charts offer visualization of the multivariate measurement of legislative quality for each jurisdiction.

A comparison of the polygonal shapes formed from the scores of each domain for each jurisdiction in the

polar chart allows for outliers and commonality to be identified. Three polar charts, one for North

American jurisdictions, European jurisdictions and Australia, and developing countries respectively, were

constructed to compare and contrast jurisdictional legislative quality. Australia was grouped with the

European nations because its regulatory approach complies with the Euratom Directive mandate of

establishing jurisdictional DRLs. Ontario’s domain scores were also overlaid onto each of the polar

charts. A well-rounded jurisdiction in terms of legislative quality would be displayed as a hexagonal

shape, with each of the domains scoring 4. Smaller polygonal shapes indicate lower overall legislative

quality in the polar chart displays.

Figure 22 shows the four North American jurisdictions. Texas has the largest polygonal shape, which

indicates better fulfillment of each of the legislative quality domains compared to the other jurisdictions.

California and Ontario both have smaller polygonal shapes, with 4 of 6 domain scores being the same.

Compared to the European nations in Figure 23, Ontario, Australia and the UK have similarly small

polygonal shapes, which suggests comparatively lower scores for each domain. Ontario scored lower in

clarity and presentation of legislative scope and transparency than Australia and the UK, but it scored the

same or better in each of the other four domains. Switzerland has the most well-rounded legislative

quality of the European jurisdictions, achieving the highest score of 4 in four domains (i.e. clarity and

presentation of legislative scope, transparency, accountability, and outcomes of non-compliance).

Ontario’s polar shape is very similar to Kenya’s shape in Figure 24, with the two jurisdictions awarded

the same score for 5 of 6 domains while Ontario scored better in the accountability domain. India’s

Page 107: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

86

polygonal shape on the same polar chart is visibly smaller because India only scored higher in the clarity

and presentation of legislative scope domain.

Figure 22: A polar chart to display the legislative quality of North American jurisdictions in the analysis. Each of the axes on the

polar chart represents one domain. Larger polygonal shapes represent higher legislative quality since each domain would

require a high score to form the larger shape.

Figure 23: A polar chart display for the legislative quality of European jurisdictions and Australia. Australia was included in this

polar chart because it uses a similar approach to European nations. Switzerland has the highest comparative legislative quality,

which is evident in its visibly large polygonal shape.

0

1

2

3

4

Clarity andPresentation of

Legislative Scope

Transparency

Accountability

Rigour of ComplianceRequirements

Outcomes of non-compliance

Fairness

BritishColumbia

California

Ontario

Texas

0

1

2

3

4

Clarity and Presentation ofLegislative Scope

Transparency

Accountability

Rigour of ComplianceRequirements

Outcomes of non-compliance

Fairness

Australia

Euratom

Germany

Ireland

Ontario

Portugal

Switzerland

Page 108: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

87

Figure 24: A polar chart to depict the comparative legislative quality of the developing nations. Ontario has an almost identical

shape to Kenya, where 5 of the 6 domains had the same scores and Ontario only scored higher in the accountability domain.

India’s polygonal shape is comparatively smaller to indicate lower legislative quality.

6.1.3 Supplemental Documents Quality Assessment

Each of the jurisdictions’ supplemental documents were evaluated against the domains compiled in Part 3

of RACT 2. A reviewer assigned individual Likert Scale scores to the evaluation criteria for each domain,

and then, provided an overall domain score. The Likert Scale employed 5 points, with 0 and 4 being the

lowest and highest possible scores respectively. The detailed scoring of each domain, with comments, for

each jurisdiction can be found in Appendix F. A summary of the domain scores for each jurisdiction is

depicted in the heat map display in Figure 25. Similar to the heat map employed in the legislative quality

assessment, the supplemental document quality scores are displayed using a graded red-green colour

scale. The scale uses 5 different shades of colours to represent the possible Likert Scale scores:

Red = 0 = extremely poor

Yellow = 1 = below average

Orange = 2 = acceptable

Light green = 3 = good

Dark green = 4 = excellent

Figure 25 provides a comparison for the domain scores of every jurisdiction with supplemental

documents. The rigor of updates domain has the lowest average of score 1.88. This is the only domain

where none of the jurisdictions scored greater than 3. The highest average domain score is 3.38 for clarity

0

1

2

3

4

Clarity andPresentation of

Legislative Scope

Transparency

Accountability

Rigour of ComplianceRequirements

Outcomes of non-compliance

Fairness

India

Kenya

Ontario

Page 109: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

88

of scope and purpose. California scored the lowest score of 2 in this domain, which is still indicative of

“acceptable” quality. The other domains were quite uniform with average scores ranging from 2.25 to

3.13, with at least one jurisdiction scoring an “excellent” score of 4 in each domain.

Domain AU BC CAN CA IAEA IE IN UK Avg

Clarity of Scope and Purpose

4 3 4 2 4 3 4 3 3.38

Evidence support and explanation for processes and recommendations

3 4 4 1 3 2 2 3 2.75

Instructive quality of writing

3 3 4 2 4 3 3 3 3.13

Adaptability 3 4 2 2 4 2 0 1 2.25

Integration of inter-professional perspectives

4 3 3 3 4 0 1 1 2.38

Rigor of expectations

3 2 2 3 4 2 1 2 2.38

Rigor of updates 3 1 2 3 2 1 1 2 1.88

Average 3.29 2.86 3.00 2.29 3.57 1.86 1.71 2.14

Figure 25: A heat map display to show the domain score for every jurisdiction. The highest scoring domain on average is clarity

of scope and purpose, with an average score of 3.38. The highest scoring jurisdiction, on average, is IAEA with an average

domain score of 3.57.

In a comparison across jurisdictions in Figure 25, IAEA’s Basic Safety Standards performed the best in

supplemental document quality with an average domain score of 3.57. The IAEA scored an “excellent”

score of 4 in five of the seven domains. Health Canada’s Safety Code 35 scored the second highest in

terms of supplemental document quality, with an average domain score of 3.00 and a minimum score of 2

to indicate “acceptable” quality across all of the domains. Contrastingly, India scored the lowest average

score of 1.71 across the seven domains, with a score of 0 to indicate extremely poor performance in the

document’s adaptability and scores of 1 to indicate below average performance in three themes (i.e.

integration of inter-professional perspectives, rigor of expectations and rigor of updates). The only other 0

awarded in this supplemental document quality assessment is to Ireland for its integration of inter-

professional perspectives in the development of its DRLs position paper.

The scores of each jurisdiction for every domain was plotted using one polar chart (Figure 26) to offer

visualization and comparison of the well-roundedness for each jurisdiction’s supplemental document.

Larger heptagonal shapes indicate stronger individual domain score, better quality and more well-rounded

Page 110: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

89

supplemental documents. Asymmetrical polygonal shapes with rough spikes indicate lower well-

roundedness since it suggests high scores in some domains and low scores in others.

Figure 26: A polar chart to visualize the overall supplemental document quality for every jurisdiction. Large heptagonal shapes

infer higher quality in all domains and therefore, better-rounded supplemental documents.

Although the IAEA’s shape is the largest and indicates the best overall quality in Figure 26, Australia’s

supplemental document appears to be better-rounded. Australia scored greater than 2 in all of the

domains, whereas the IAEA scored more 4s comparatively but received a 2 in the rigor of updates. Askew

shapes include India, Ireland and British Columbia. British Columbia performed well in five of the seven

domains, but the jaggedness results from low scores of 2 and 1 in the rigor of expectations and rigor of

updates domains, respectively. Ireland’s polygonal shape is comparatively small in the polar chart

because Ireland did not score greater than 3 in any of the domains. Comparatively, India scored a 4 and 3

in the clarity of scope and purpose domain and instructive quality of writing domains, respectively, to

form large spikes in an otherwise small polygonal shape.

6.2 Diagnostic Reference Levels Assessment

A summary of dose levels in the jurisdictions provides insight into the success that each regulatory

approach has had in dose optimization. Secondly, the relationship between domain scores of each

jurisdiction and the dose trends offers preliminary validation of RACT 2. Separate analyses were

0

1

2

3

4

Clarity of Scopeand Purpose

Evidence supportand explanation

for processes andrecommendations

Instructive qualityof writing

AdaptabilityIntegration of

inter-professionalperspectives

Rigour ofexpectations

Rigour of updates

AustraliaBCCanadaCaliforniaIAEAIrelandIndia

Page 111: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

90

performed for jurisdictions with official and legally binding DRLs, and dose survey results from

independent researchers that attempt to propose DRLs.

6.2.1 Official DRLs Comparison

Official DRLs describe the target dose levels that were established by jurisdictions for typical

examinations based upon groups of standard-sized patients or standard phantoms. When DRLs are used

by a jurisdiction in an official capacity, they are not expected to be exceeded for routine procedures when

normal technical and diagnostic practices are applied [68]. Therefore, the official DRLs for routine scans

were reviewed and compared due to the analogous purpose for their establishments within each

jurisdiction. For example, member states of Euratom were mandated to “promote the establishment and

use of diagnostic reference levels for radiodiagnostic examinations, and the availability of guidance for

this purpose having regard to European diagnostic reference levels where available. [68]” Australia is the

only non-Euratom member state that has national DRLs. Similar to the Euratom member states, national

DRLs were established in Australia for the purpose of providing “indicative dose metrics for current

imaging practice in Australia, allowing individual facilities to compare their facility reference dose

metrics against a national benchmark. [125]”

Current official DRLs were analyzed using the documents highlighted in blue font in Table 5 for the

following jurisdictions: Australia, Germany, Ireland, Switzerland and the UK. Each of the jurisdictions,

except Ireland, employed national dose surveys to collect the required dose data to establish the 75th

percentile mark for routine scan types, which is the accepted definition of target DRLs [100]. Ireland’s

official DRLs were established through review of the recommended practices in literature [126].

However, the sample size of the dose surveys and the dose measurement methods differ across

jurisdictions.

Table 17 provides a summary of the data collection methods for each jurisdiction. The broad categories of

examinations in this analysis follow the Radiation Protection n˚ 154 (RP154) methodology for

categorization of x-ray examinations [127]. The RP154 methodology was designed to be useful in

following trends and comparing doses across countries in a consistent manner [127]. These general

categories are sorted according to regions of the body or organ system, and encompass different

examinations that are used to answer specific diagnostic problems or clinical questions during one visit to

the radiology department, hospital or clinic [127]. Regardless, there are potential limitations in the

categorization that should be considered when comparing dose levels across jurisdictions, which are

discussed in Section 6.2.3. The comparisons of official DRLs should, therefore, only be considered as a

Page 112: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

91

high-level review of existing dose trends. Statistical analyses were deemed inappropriate due to the

variable methodologies and definitions in the jurisdictional dose surveys.

Table 17: A summary of the data collection methodology undertaken by each jurisdiction to establish the official DRLs

Jurisdiction Data Collection Methodology

Australia (ARPANSA’s

national survey)

-Web based survey that collects “practice reference levels (PRLs)” for each scan

type, which is the median CTDIvol or DLP values [128]

-Each facility must use data from at least 10 patients (ideally 20 patients) for each

scan type to establish PRLs [128]

-Patient weights are limited to 70 kg +/- 5 kg [128]

-Official DRLs were based upon 51 surveys submitted by facilities, and the DRL

values were the 75th percentile of the PRLs from each facility [128]

Germany

(Federal Office of Radiation

Protection’s survey-

translated from German)

-Surveys were sent to CT facilities across the country [129]

-Accepts doses from standard phantoms (i.e. body phantoms are 32 cm in diameter

and 14-15 cm in length; head phantoms are 16 cm in diameter and 14-15 cm in

length [34]) and a conversion factor is provided to calculated patient dose,

assuming patient is 70 kg +/- 3 kg [129]

-Accepts mean doses from 10 patients of the standard patient size [129]

Switzerland (Treier et al.) -179 CT scanners were audited on site to collect patient doses [130]

-Correction factors were generated for deviations from measured CTDI to the

nominal weighted CTDI displayed on the console [130]

-Doses were collected using acrylic standard phantoms [130]

Ireland (Medical Council’s

Official Position Paper)

-Official DRLs were proposed based on measurements made in a number of

European Countries [131]

-Gathered data from “European Guidelines on Quality Criteria for Computed

Tomography” by the European Commission [131], [126]

United Kingdom (Public

Health England’s National

survey)

-Surveys were sent to all CT facilities in the UK [132]

-DRLs were determined from 182 scanners located in 127 hospitals [132]

-Encouraged the submission of patient doses for 20 standard-sized patients and

each patient’s body mass, traverse width, anteroposterior width and cross-

sectional areas were collected as well [132]

Figure 27 to Figure 34 show the respective official DRLs in each jurisdiction for the following exam

categories: head-related, face-related, neck-related, chest, abdomen, pelvis, trunk-related and lumbar

spine. When a jurisdiction has more than one examination belonging in a category, the established DRLs

for both exam types are displayed for comparison purposes. The examination name for each scan is

documented verbatim from the respective jurisdictional official DRL documents. Further explanations of

the clinical indication for the exam are sometimes provided in brackets. The DRL values reported in DLP

measurements were selected for comparison because it is representative of the entire scan series and

Page 113: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

92

therefore, the overall dose provided to a patient for a specific clinical indication. Graphical comparisons

of the CTDIvol measurements for the same exam types are provided in Appendix G.

Figure 27: The official DRL values for each jurisdiction’s head-related CT scans. Ireland has the highest DRL value for the

routine head scan at 1000 mGy-cm [128], [129], [130], [131], [132]

Figure 28: A graphical display to compare the face-related DRL values. Switzerland and Ireland have higher DRL values

compared to the German DRLs for specialized face-related exams [129], [130], [131]

Figure 29: A comparison of the official DRLs for neck-related exams. Switzerland's DRL value for neck exams is set 100 mGy-cm

lower than the analogous neck exam DRL value for Australia [128], [130], [132]

950 1000 1000 1000 1050 970

0

200

400

600

800

1000

Germany, Skull/Brain Australia, Head Switzerland,Skull/brain

Switzerland, brain(vascular)

Ireland, routine head UK, brain (whole)

Do

se L

engt

h P

rod

uct

(m

Gy-

cm)

Head Examination (Country, Exam type)

250

100

350 350

0

100

200

300

Germany, Facial(tumour diagnostics)

Germany, Facial(sinusitis )

Switzerland, Sinus Ireland, Face andsinuses

Do

se L

engt

h P

rod

uct

(m

Gy-

cm)

Face Examination (Country, Exam Type)

600

500

600 600

0

200

400

600

Australia, Neck Switzerland, Neck Switzerland,Cervical spine

UK, cervical spineDo

se L

engt

h P

rod

uct

(m

Gy-

cm)

Neck Examination (Country, Exam type)

Page 114: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

93

Figure 30: A comparison of the official DRLs for chest-related examinations. Ireland has comparatively the highest DRL value

for these exams, whereas Switzerland's thorax exam has the lowest DRL value [128], [129], [130], [131], [132]

Figure 31: A graphical display of the official DRL values for abdomen examinations. The first three bars show the values for

upper abdomen exams, whereas the latter three bars are for routine abdomen examinations. [129], [130], [131], [132]

Figure 32: The official DRL comparisons for pelvis-related examinations. Germany's DRL for pelvis exams is comparatively the

lowest at 450 mGy-cm. [129], [130], [131]

400450

400450

650 610

0

200

400

600

800

Germany, thorax Australia, chest Switzerland,thorax

Switzerland,thorax (vascular)

Ireland, chest UK, chest (lungcancer)

Do

se L

engt

h P

rod

ut

(mG

y-cm

)

Chest Examination (Country, Exam Type)

520400 450

900780

910

0

200

400

600

800

1000

Ireland, liver andspleen

Switzerland,upper abdomen

Germany, upperabdomen

Germany,abdomen

Ireland, routineabdomen

UK, abdomen(liver metastases)

Do

se L

engt

h P

rod

uct

(m

Gy-

cm)

Abdomen Examination (Country, Exam type)

450500

570

0

100

200

300

400

500

600

Germany, pelvis Switzerland, pelvis Ireland, routine pelvis

Do

se L

engt

h P

rod

uct

(m

Gy-

cm)

Pelvis Examination (Country, Exam type)

Page 115: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

94

Figure 33: A comparison of the trunk-related DRL values for the jurisdictions with official DRLs. The first three bars indicate the

DRL values for abdo-pelvis exams, whereas the latter three bars indicate the chest-abdo-pelvis examination DRLs [128], [130], [132]

Figure 34: A comparison of the official DRL values for lumbar-spine related exams. Germany's exams are divided into

specialized exam types, which results in comparatively lower DRL values. [128], [129], [130]

Ireland’s official DRLs are comparatively higher for most of the scans. For example, Figure 27 shows

Ireland’s routine head DRL is set at 1050 mGy-cm, whereas the other jurisdictions are equal or lower to

1000 mGy-cm. Secondly, Australia’s official DRLs also tend to be higher than the other jurisdiction’s

DRLs. An example of its comparatively higher levels is the routine neck scan shown in Figure 29, where

Australia’s established DRL value of 600 mGy-cm is 100 mGy-cm higher than the other jurisdiction that

has an official DRL for neck scan, Switzerland. Generally, Switzerland’s DRL values tend to be

comparatively lower than the other jurisdictions in similar scan types. Figure 33 shows Switzerland’s

abdo-pelvis DRL value at 650 mGy-cm, which is almost 100 mGy-cm lower than UK’s value for abdo-

pelvis exams used to detect abscess. The purpose of the exam may contribute to the difference in dose

levels.

700 650745

1000 1000 1000

0

200

400

600

800

1000

Australia, abdo-pelvis

Switzerland, abdo-pelvis

UK, abdo-pelvis(abcess)

Australia, chest-abdo-pelvis

Switzerland, thorax-abdo-pelvis

UK, chest-abdo-pelvis

Do

se L

engt

h P

rod

uct

(m

Gy-

cm)

Trunk Examination (Country, Exam type)

250

500

1000850

0

200

400

600

800

1000

1200

Germany, lumbar spine(intervertebral disc axially)

Germany, lumbar spine(bone-spiral)

Australia, lumbar spine Switzerland, lumbar spine

Do

se L

engt

h P

rod

uct

(m

Gy-

cm)

Lumbar Examination (Country, Exam type)

Page 116: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

95

Germany’s DRL levels are established for scans that are more specific than the general “routine”

examinations, and so, Germany’s DRL levels are noticeably different than the other jurisdictions. For

example, Germany sub-divides the lumbar-spine exams into axially imaged intervertebral discs and spiral

bone, whereas the UK and Switzerland simply provides DRL values for lumbar spine as a whole. This

resulted in Germany’s lumbar spine related scans having DRL values of 25 mGy-cm for intervertebral

discs and 500 mGy-cm for spiral bone as shown in Figure 34, while the UK’s and Australia’s lumbar-

spine DRL values are 850 mGy-cm and 1000 mGy-cm, respectively. Moreover, the face-related scan

values for Germany are also systematically lower than Ireland and Switzerland’s DRL values for similar

exam types because Germany’s values are for more specialized division of exams. The most consistent

DRL value across jurisdictions is for the chest-abdo-pelvis combination scan displayed in Figure 33,

where Switzerland, Australia and the UK all assigned the 1000 mGy-cm as the official DRL.

Another informative approach to analyzing dose trends is to review the changes to the official DRLs over

time. Advances in technology and increased awareness for radiation safety have contributed to the

changes in dose over time. Table 18 to Table 20 summarize the DRL value changes over time for the

jurisdictions that regularly review and update their dose levels (i.e. Germany, Switzerland and the UK).

DRL values are only reported in the comparison tables if there is more than one available value for the

same exam type. Both Ireland and Australia were excluded from the dose trend over time analyses

because Ireland has not updated their DRLs officially since the Medical Council first proposed values in

2004 and Australia’s 2011 national DRLs are the initial DRLs established for the jurisdiction.

Table 18: A comparison of Germany's official DRL values in 2003 and 2011.

Examination Type CTDIvol (mGy) DLP (mGy-cm)

20031 20112 20031 20112

Skull 60 65 1050 950

Facial (sinusitis) 35 9 360 100

Thorax 22 12 650 400

Upper abdomen 25 20 770 450

Abdomen 24 20 1500 900

Lumbar spine (intervertebral disc diagnosis) 47 42 280 500

1 2003 doses were reported from [133] and [134] 2 2011 doses were provided in [129]

Page 117: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

96

Table 19: A comparison of Switzerland's official DRLs in 2003 and 2011.

Examination Type CTDIvol (mGy) DLP (mGy-cm)

20031 20111 20031 20111

Skull/brain 60 65 1000 1000

Brain (vascular) 80 65 1000 1000

Sinus 30 25 450 350

Petrous bone 30 50 150 250

Neck 30 20 600 500

Cervical spine 30 30 600 600

Shoulder 30 30 450 500

Thorax 10 10 350 400

Thorax (vacular) 15 15 450 450

Thorax/upper abdomen 15 15 600 600

Upper abdomen 15 15 300 400

Upper abdomen (vascular) 20 15 400 500

Abdo-pelvis 15 15 700 650

Abdo-pelvis (vascular) 20 15 650 650

Pelvis 10 20 200 500

Pelvis (vascular) 15 20 300 500

Thorax-abdo-pelvis 20 15 1100 1000

Lower limbs 10 15 700 1000

Heart (cardiovascular) 50 50 1000 1000

Heart 10 10 150 150

1 2003 and 2011 doses were provided from [130]

Table 20: A comparison of the UK's official DRLs in 1999, 2003 and 2011

Examination Type CTDIvol (mGy) DLP (mGy-cm)

19991 20031 20111 19991 20031 20111

Head (acute stroke)- whole exam - - - 1050 7602/9303 970

Chest (lung cancer)-whole exam - - - 650 4302/5803 610

Chest (interstitial lung disease)-high resolution-

whole exam

- - - 280 802/1703

Abdomen (liver metastases) - 14 14 900 4602/4703 910

Abdo-pelvis (abscess) - 14 15 780 5102/5603 745

Chest-abdo-pelvis (cancer) - 14 - - 7602/9403 1000

1 A comparison of DRL values for 1999, 2003 and 2011 was provided in [132] 2 DRL values for SSCT

3 DRL values for MDCT

Page 118: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

97

Germany’s official DRL values decreased for all of the examination types in both the CTDIvol and DLP

measurements, except for the braincase exam’s CTDIvol measurement and the DLP value for the

intervertebral disc diagnosis in the lumbar spine. In fact, the dose decreases for entire exams in DLP were

substantial. For example, Table 18 shows that Germany’s DRL value for abdomen exams decreased by

600 mGy-cm in the 8 year period and the DRL value for thorax exams decreased by 250 mGy-cm.

Switzerland’s DRL values remained fairly consistent across the exams as shown Table 19, although there

are some notable increases in the official DRL values in both CTDIvol and DLP measurements over the 8

year period. The official CTDIvol values increased for the following examination types: skull/brain,

petrous bone, pelvis, pelvis (vascular) and lower limbs. Secondly, official DLP values increased for the

following exam types: petrous bond, shoulder, thorax, upper abdomen, upper abdomen (vascular), pelvis,

pelvis (vascular) and lower limbs. Moreover, the DLP values for pelvis and lower limbs both increased by

a sizeable 300 mGy-cm. as shown in Table 19.

The changes in official DRL values for the UK are documented in Table 20. The 1999 CTDI values were

not documented because it was presented in CTDIw rather than CTDIvol. There was a trend of decreasing

DRL values from 1999 to 2003 for DLP measurements in all exam types. However, the noticeable

increases in DRLs for comparable exams in values of DLP from 2003 to 2011 saw the dose distributions

return to similar dose levels as those in 1999. In addition to the introduction of 64-slice scanners in 2004

and 320-slice scanners in 2007, the authors of the paper hypothesized that the variation in data collection

methodologies between the 2003 and 2011 dose surveys also likely contributed to the higher dose level

[132]. While the 1999 and 2003 dose surveys collected standard CT protocols, the 2011 survey attempted

to collect sets of data in relation to individual patients to provide better indications of typical practice at

each CT facility [132]. The 2011 survey, therefore, was able to collect information on technique for

47,000 patient, representing 24,000 separate scan sequences [132]. It can be observed that the CTDIvol

values for comparable exam types remained similar for the SCDT and MDCT scanners, but the

increasingly complex scan techniques resulted in higher DLP per complete examinations. For example,

lower DLP values were reported for single axial sequence of head exams while the highest mean values

were associated with helical scanning of the head, and exams involving multiple sequences [132]. The

difference in CT scanning techniques resulted in large variations in doses between CT facilities, which

suggests that there is a need for individual institutions to optimize scan parameters in relation to their

clinical purpose, such that patient radiation protection is consistent and improved throughout the

jurisdiction.

Page 119: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

98

6.2.2 Peer-reviewed Dose Survey Articles

Dose survey articles by independent research groups were reviewed, and the reported dose levels or

proposed DRL values were used for a comparison analysis of dose trends for those jurisdictions that do

not have legally binding DRLs mandated by the governing authorities. The dose level articles highlighted

in orange font in Table 5 were used for this dose level comparison analysis. Due to the large number of

variables in the data collection and analysis methodologies, direct dose comparisons and statistical

analyses of the data were deemed inappropriate. An explanation of the limitations to comparison of the

published dose levels in peer-reviewed article is provided in Section 6.2.3.

The variables in the comparisons (e.g. sample size, sample coverage, year of dose survey) should be

considered when reviewing the dose level comparisons. Unlike the graphical format used to present the

official DRL data in the previous section, results of the dose surveys are simply reported in Table 21. It is

important to recognize that the purpose of this comparison analysis is only to provide a general

understanding of the differences in dose levels across jurisdictions through observations of general trends.

Table 21 provides a summary of the relevance of the data (i.e. publication and dose survey dates), the data

collection and analysis methodologies as well as an overview of each dose article’s findings.

Page 120: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

99

Table 21: A summary of peer-reviewed publications that provide insight into the dose levels of each of the selected jurisdictions. Information is provided for the data collection

and analysis method, the publication and dose survey dates and the reported findings.

Jurisdiction Publication date; Dose survey date

Data Collection and Methodology Findings Summary

British Columbia (Aldrich et al.)

2006; 2004 -Survey of 1070 patients from 18 radiology departments in BC -Average patient age was 59.4 (range was 13-98) -Average patient weight was 74.6 kg (range 27.3 to 175 kg) -DRL values were based on 75th percentile of the DLP distribution -Scan parameters were not changed in response to patient weight [135]

DRL values (75th percentile of dose distribution) in DLP and effective dose from [135] Head: 1300 mGy-cm; 2.8 mSv Chest: 600 mGy-cm; 9.0 mSv Abdomen: 920 mGy-cm; 10.2 mSv Pelvis: 650 mGy-cm; 9.1 mSv Abdo-pelvis: 1100 mGy-cm; 16.5 mSv

Canada (from IAEA article)

2006; not stated -CT dose index measurements (CTDIW and CTDIvol) were performed at participating CT scanners using a pencil-shaped ionization chamber and standard PMMA phantoms -Doses were documented from the console after calibration with standard phantoms -97 patients for head CT, 243 patients for chest CT, and 293 patients for abdominal CT -Average age for head and abdominal CT: 52 years -Average age for chest CT: 54 years -Average patient weight: 65 kg (due to the lower average weight of Asian individuals -Only mean dose values were recorded for individual countries -DRL values were calculated as the 75th percentile of the overall mean dose across 6 countries: Canada, Greece, India, Poland, Thailand, United Kingdom [136]

Mean dose values only (CTDIvol; DLP) from [136] Chest: 8.8 mGy; 294 mGy-cm Abdomen: 14.4 mGy; 696 mGy-cm

India 3 (from IAEA article)

Mean dose values only (CTDIvol; DLP) from [136] Chest: 12.3 mGy; 355 mGy-cm Abdomen: 12.6 mGy; 459 mGy-cm

Ontario (from preliminary

OHTAC presentation)

2013; March 2012 - March 2013

-Three Ontario sites were used for data collection and analysis -Data extracted using the eXposureTM software -Mean dose values were calculated [137]

Mean dose values only (CTDIvol; DLP; Effective dose) from [137] -Head: 77.2 mGy; 1406.5 mGy-cm; 2.9 mSv -Chest: 9.4 mGy; 324.2 mGy-cm; 6.1 mSv -Abdo-pelvis: 19.0 mGy; 803.3 mGy-cm; 14.2 mSv -Cervical spine: 24.7 mGy; 583.6 mGy-cm; 5.7 mSv -Lumbar spine: 36.4 mGy; 920.5 mGy-cm; 16.4 mSv

Page 121: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

100

California 2009; January – May 2008

-Data collected from 4 institutions in the San Francisco Bay Area in California -Sampled 20-30 patients that are 18 years old or older for each examination type from every institution (n=1119) -Sample size for each scan type: Routine head- 120 Routine neck- 115 Suspected stroke-87 Routine chest, no contrast- 120 Routine chest, with contrast- 120 Routine abdo-pelvis, no contrast- 120 Routine abdo-pelvis, contrast- 117 Multiphase abdo-pelvis- 110 -Median and 75th percentile values (proposed DRL) are only provided in effective dose units after being converted from the recorded DLP values [138]

Median dose values (Effective dose) from [138] Routine head: 2 mSv Routine neck: 4 mSv Suspected stroke: 14 mSv Routine chest, no contrast: 8 mSv Routine chest, contract: 8 mSv Routine abdo-pelvis, no contrast: 15 mSv Routine abdo-pelvis, contrast: 16 mSv Multiphase abdo-pelvis: 31 mSv

Third quartile values (Effective dose) from [138] Routine head: 3 mSv Routine neck: 6 mSv Suspected stroke: 20 mSv Routine chest, no contrast: 11 mSv Routine chest, contrast: 12 mSv Routine abdo-pelvis, no contrast: 20 mSv Routine abdo-pelvis, contrast: 20 mSv Multiphase abdo-pelvis: 43 mSv

Japan 1 (Fukushima et al.)

2012; June 2010 -Survey sent to all hospitals and clinics with CT scanners in the Gunma prefecture -Data collected from 60 hospitals and 20 clinics -The information displayed on the console was used to record the dose -Number of adult (> 19 years old) scans analyzed per exam type: Head-4587; Face-340; Neck-339; Chest-2052;

Median values (DLP) from [139] Head: 820 mGy-cm Face: 320 mGy-cm Neck: 350 mGy-cm Chest: 399 mGy-cm Upper abdomen: 421 mGy-cm Lower abdomen: 240 mGy-cm Upper or lower extremities: 218 mGy-cm Heart: 1049 mGy-cm

Page 122: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

101

Upper abdomen-2175; Lower abdomen-281; Upper or lower extremities-185; Heart-629 - Median values and proposed DRL values (i.e75th percentile value of the DLP distribution) were provided as DLP measurements for each scan type -Average patient weight was not disclosed [139]

Proposed DRL value in DLP (Rounded 75th percentile of dose distribution) from [139] Head: 1120 mGy-cm Face: 450 mGy-cm Neck: 520 mGy-cm Chest: 580 mGy-cm Upper abdomen: 680 mGy-cm Lower abdomen: 350 mGy-cm Upper or lower extremities: 640 mGy-cm Heart: 1510 mGy-cm

Japan 2 (J-RIME study)

2015; 2014 -Surveys were sent to hospitals and clinics with CT scanners -Deemed as the “official” DRLs -Dose collection and analysis was not specified -Average patient weight: 50-60 kg -Methodology to arrive at the proposed DRL values is not disclosed [140]

Proposed DRL values (CTDIvol; DLP) from [140] Routine brain: 85 mGy; 1350 mGy-cm Routine chest: 15 mGy; 550 mGy-cm Chest-abdo-pelvis: 18 mGy; 1300 mGy-cm Abdo-pelvis: 15 mGy; 1000 mGy-cm Multiphase liver1: 15 mGy; 1800 mGy-cm

India 1 (Livingstone et al.)

2011; 2006-2008 -Survey carried out in 25 districts of Tamil Nadu, covering a total of 127 CT scanners -Doses were measured using standard PMMA phantoms -Mean doses recorded in DLP and effective doses -75th percentile of dose distribution recorded in DLP [141]

Mean dose (DLP; effective dose) from [141] Thorax: 476 mGy-cm; 8.04 mSv Abdomen: 445.8 mGy-cm; 6.69 mSv Pelvis: 251.9 mGy-cm; 4.79 mSv

75th percentile (DLP) from [141] Thorax: 557 mGy-cm Abdomen: 521 mGy-cm Pelvis: 294 mGy-cm

India 2 (Saravanakumar et

al.)

2014; undisclosed -Survey included 6 CT scanners in six different radiology departments in Pudhuchery (enclave of Tamil Nadu, India) -Doses were measured using two methods: using a 10-cc ionization chamber and standard PMMA phantoms and through patient scans (50 head, 50 chest and 50 abdomens procedures for every scanner) -Patient data were adjusted based on the phantom determined doses -75th percentile CTDIVOL and DLP values were calculated [142]

Proposed DRLs (75th percentile of dose distribution in CTDIvol and DLP) from [142] Head: 32 mGy; 925 mGy-cm Chest: 12 mGy; 456 mGy-cm Abdomen: 16 mGy; 482 mGy-cm

Ireland (Foley et al.)

2012; 2010-2011 -Survey was distributed to 40 CT sites fir 9 examinations -34 scanners were included in the data analysis (~54% of Irish CT scanners at the time)

Proposed DRL values (rounded 75th percentile value of dose distribution in DLP) from [12] Head: 940 mGy-cm

Page 123: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

102

-Dose data were collected for a minimum of 10 patients per exam type at each facility -Inclusion patient weight: 60-80 kg -Proposed DRLs using the 75th percentile of the dose distribution [12]

Sinuses: 210 mGy-cm Cervical spine: 420 mGy-cm Chest (and liver) 390 mGy-cm Abdo-pelvis: 600 mGy-cm Multiphase abdomen: 1120 mGy-cm Chest-abdo-pelvis: 850 mGy-cm

Kenya (Korir et al.) 2015; 2012 -Data analysis was performed using 10 out of 15 responses from facilities (not enough detail in the other 5 responses) - total of 3178 patients were analyzed for all the exam types -Average male adult weight is 69 kg; average female adult weight is 71 kg -Standard phantoms were used to establish the acceptance level between actual dose and dose displayed on the console -The patient dose values were corrected based on the measured phantom CT doses -Proposed DRLs are 75th percentile values of dose distribution [143]

Proposed DRL values (75th percentile of dose distribution in CTDIvol, DLP and effective dose) from [143] Brain: 61 mGy; 1612 mGy-cm; 3 mSv Sinuses: 41 mGy; 700 mGy-cm; 1 mSv Facial bones: 38 mGy; 1169 mGy-cm; 2 mSv Neck: 16 mGy; 1010 mGy-cm; 5 mSv Cervical spine: 34 mGy; 1015 mGy-cm; 5 mSv Chest: 19 mGy; 895 mGy-cm; 13 mSv Abdomen: 20 mGy; 1842 mGy-cm; 28 mSv Pelvis: 21 mGy; 1928 mGy-cm; 25 mSv Lumbar spine: 20 mGy; 712 mGy-cm; 12 mSv Liver: 18 mGy; 2197 mGy-cm; 23 mSv

Portugal 1 (Santos et al.)

2013; June 2011- January 2012

-Internet survey was sent to all CT scanners (211 institutions) across the 5 health administrations in Portugal -Responses were received from 23 public institutions and 18 private institutions -Survey designed in accordance with European Guidelines set in RP154 -Proposed DRLs were based on 75th percentile of dose data -QA records were reviewed to ensure quality control testing was performed accordingly [144]

Proposed DRL values (75th percentile of dose data in CTDIvol and DLP) from [144] Head: 75 mGy; 1010 mGy-cm Neck: 20 mGy; 465 mGy-cm Chest: 14 mGy; 470 mGy-cm Cervical spine: 39 mGy; 600 mGy-cm Abdomen: 18 mGy; 800 mGy-cm Pelvis: 18 mGy; 645 mGy-cm Lumbar spine: 38 mGy; 845 mGy-cm

Portugal 2 (Teles et al. report for Dose Datamed)

2012; mid Oct to late Nov 2010

-Dose data collected from 11 out of 30 academic studies discussing dose in Portugal as well as pilot studies in 10 hospitals and 7 health centres -Dose Datamed questionnaire was used to survey each institution -Mean effective doses are reported for each exam type [145]

Mean effective doses from [145] Skull/brain: 2.04 mSv Neck: 2.13 mSv Chest: 4.93 mSv Abdomen: 6.94 mSv Pelvis: 4.28 mSv

Page 124: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

103

Dose trends can only be summarized by analyzing articles that report dose survey results using the same

radiation dose units. The availability of peer-reviewed articles that intrinsically contrast dose levels in

more than one jurisdiction offers a convenient means of comparison. The IAEA dose comparison article

from 2006 in Table 21 provides insight into the mean dose levels of Canada and India. India has a higher

dose level for chest exams whereas Canada has a comparatively higher dose level for abdomen exams.

However, the data were obtained via surveys through a local contact person and the definition of these

routine exams may vary within the jurisdiction. More recently reported mean dose values also offer high-

level insight into the CT radiation dose management situation in each jurisdiction despite small sample

sizes. For example, the mean effective dose measured by Portugal’s Dose Datamed 2 project for chest

examinations was 4.93 mSv, which is lower than the representative data from three sites in Ontario that

measures the mean effective dose of chest exams at 6.1 mSv.

The articles highlighted in blue font from Table 21 that propose DRLs for a jurisdiction can be used to

provide approximate cross-jurisdictional comparisons because they provided the following commonalties

in the dose data collection and analysis methods. Firstly, these articles followed the Euratom convention

of proposing the DRLs as 75th percentile CTDIvol and/or DLP values of the dose data. Secondly,

jurisdiction-wide dose surveys were distributed in an attempt to obtain the largest possible sample dataset.

Aldrich et al.’s study was excluded from this comparison because the reported dose survey was conducted

in 2004 [135]. Dose survey results can only accurately be compared if they were conducted within the

same time period because CT technology and imaging techniques have advanced substantially in the past

decade, especially with the increased use of MDCT. For example, the 64-slice scanner was only

introduced around 2004-2005 [132], [146] and so, Aldrich et al.’s study did not explore the doses from

scanners with >64 slices, whereas articles published post-2010 contain information from MDCTs capable

of >64 slices.

Kenya’s proposed DRL values from Korir et al. are noticeably higher compared to both Japan and

Portugal’s proposed DRLs. For example, Table 21shows that Kenya proposed a DRL value of 895 mGy-

cm for chest examinations, whereas Portugal’s Santos et al. proposed 470 mGy-cm and Japan’s proposed

DRLs was 550 mGy-cm from the J-RIME study, respectively. Unfortunately, Santos et al.’s and J-

RIME’s proposed DRLs were for different scan types, which makes comparison analyses inapplicable. A

quick review of the proposed doses and the official DRLs in Section 6.2.1 suggests that Portugal’s

proposed DRLs are on par with the jurisdictions with official DRLs. For example, Santos et al. proposed

600 mGy-cm as the cervical spine exams’ DRL value [144], which is the same as Switzerland and the

UK’s established value. On the other hand, Japan’s proposed DRLs are systematically higher than those

Page 125: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

104

that already exist in jurisdictions with official DRLs as shown in the proposed chest-abdo-pelvis DRL of

1300 mGy-cm [140], which is 300 mGy-cm than the existing DRL value of 1000 mGy-cm for chest-

abdo-pelvis exams in the UK, Switzerland and Australia summarized in Figure 33.

6.2.3 Dose Level Summary

To facilitate subsequent discussion and analysis, the countries and/or states that were comparatively

successful at CT dose management must first be identified to provide a thorough overview of the

relationships between jurisdictional regulatory approaches and dose trends. “Successful” jurisdictions

were defined as the countries and/or states that have comparatively lower proposed or established DRL

values for analogous scan types. Systematically lower DRLs were also deemed as a sign of “success” in

dose optimization. From a broad comparison of proposed or established DRLs, Germany, Ireland,

Australia, Switzerland, the UK and Portugal all have comparable DRL values that together are

systematically lower than other jurisdictional proposed or existing DRL and therefore, were classified as

“strong” jurisdictions. Ireland’s official DRL values were systematically higher, but these values are not

indicative of the dose distribution of Ireland since they were developed from literature review in 2004.

Foley et al.’s dose survey is more indicative of the dose situation in Ireland due to its recentness and the

dose data collection method that is comparable to the establishment of DRLs in other jurisdictions.

The jurisdictions with systematically higher proposed DRLs are Japan and Kenya, which suggests they

have a less successful regulatory approach. Japan and Kenya were, therefore, classified as “weak”

jurisdictions. The remaining jurisdictions were not classified due to the large differences in their data

collection and analysis methodologies, which deemed them incomparable to the classified jurisdictions.

It should also be noted that Saravanakumar’s et al.’s study from India also proposed comparable DRLs to

the strong jurisdictions. However, the study only covered an enclave of Tamil Nadu and is not

representative of India as a whole. India was, therefore, not classified based on their dose survey results.

Ontario’s preliminary analysis provided data for three sites and findings were presented as mean doses,

which deemed the findings incomparable to other dose articles or official DRLs. However, a brief review

of the findings showed that the mean dose values without inclusion of outliers for head and abdo-pelvis

exams in Ontario are actually higher than the 75th percentile values other jurisdictions have proposed or

established as DRLs. This provided a glimpse of the need for changes in the CT dose management

approach in Ontario.

Page 126: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

105

6.2.3 Limitations of Dose Level Comparisons

There are inherent limitations to dose level comparisons that should be considered when reviewing the

results of the comparison analyses. The first consideration is the variation in technologies that are

employed in CT facilities. As shown in Table 20, single slice CT scanners (SSCT) and multi-detector CTs

(MDCT) resulted in different dose distribution for the same exam types, which manifested as different

DLP values for the official DRLs in 2003. Furthermore, doses were often recorded from the display

console of each CT scanner but there is not consistent confirmation that efforts were made to correct the

measured dose from phantoms and the displayed dose in all of the dose surveys. The lack of consistency

contributes to potential inaccuracies in the data comparison.

Secondly, the results of dose surveys are often self-reported by the CT facility where the classification of

exam types may vary. For example, head-related exams were sub-divided into further categories (e.g.

sinus, skull/brain) by some jurisdictions and researchers, therefore it is unclear as to whether “routine”

head exam doses reported by some facilities encompassed similar sub-divisions of exams. For more

accurate comparisons, verification of the clinical indication for each patient scan in a dose survey is

required to ensure that only analogous scans are used to develop DRLs for specific exam types.

Furthermore, analysis of acquisition parameters by protocol will also contribute to increased

comparability across dose surveys (e.g. contrast vs. non-contrast).

Dose level surveys by independent researchers are subject to more intrinsic limitations because there is

higher variability in the dose collection and analysis methodologies employed by independent

researchers. While most jurisdictions employed jurisdiction-wide surveys to establish DRLs, independent

researchers used varying data collection methods, including administration of dose surveys, retrospective

analyses of patient dose records through the Picture Archiving and Communication System, and on-site

measurements using standard phantoms. Dose surveys distributed by independent researchers lack legal

authority and so, resulted in smaller datasets. Smaller datasets are more disposed to systematic bias and

the confidence intervals of the data are affected. Furthermore, some of the dose surveys only sampled

from small administrative divisions (e.g. province, state, and district) of the jurisdiction. These samples

can only be used to provide preliminary insight into a jurisdiction’s overall dose levels, and cannot be

applied accurately in cross-jurisdictional dose comparisons. Lastly, the peer-reviewed dose level articles

were conducted at various times, so the applicability of the dose levels to current standards and

technologies vary. This limitation is avoided in official DRL comparisons because the legal authority of

the DRLs ensure continued relevance to CT facilities.

Page 127: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

106

6.3 Discussion and Analysis

Relationships and trends in the evaluation results using RACT 2 and the general dose level comparisons

were explored to elicit key elements that may have an impact on the success of dose regulatory policy

implementation. Information extracted from the expert interviews with jurisdictional representatives listed

in Table 6 was used to further support the findings. This discussion served as informative best practices

on radiation protection of medical exposures regulation design and implementation.

6.3.1 Relationship between RACT 2 Evaluations and General Dose Trends

From the RACT 2 evaluations, high scoring themes and domains that recur in the radiation protection

publications can be extracted. Rough correlations between the scores and the dose levels can provide

insight into the factors that are important in the design of CT dose management regulations.

6.3.1.1 Key Themes

Legislation Assessment

From the results of the comprehensiveness analysis for radiation protection legislations, the general

provisions theme had the highest average fulfillment from the jurisdictions. General provisions describe

the scope and purpose of the document, which essentially provides the basis of understanding for users.

High fulfillment of this theme across jurisdictions indicate that it is important to ensure targeted users of

legislation are all in agreement of the standards and their associated applications. The licensing and

accreditation theme had the second highest average fulfillment, especially in the sub-themes of basic

general standards and application process. India legislation was basic in content and did not allude to any

clinically relevant dose optimization measures such as clinical justification of CT exams or the ALARA

principle. However, the legislations from India and Kenya did provide substantial information about the

licensing and accreditation requirements for CT facilities, which suggests that license acquisition is the

most rudimentary standard employed to oversee CT use.

A comparison of the average percentage fulfillment values of each theme for the strong jurisdictions and

the overall average percentage fulfillment of each theme (Appendix H) revealed that the fulfillment of -

dose optimization related themes were systematically higher for the strong jurisdictions. Kenya, a

representatively weak jurisdiction, contrasts starkly against the strong jurisdictions in terms of percentage

fulfillment of the dose optimization related themes. Dose optimization related themes (i.e. operational

requirements, personnel requirements, radiation protection/quality assurance committee, and diagnostic

reference levels) encompass the different regulatory approaches that jurisdictions have undertaken to

encourage dose awareness and regulate prescription of radiation exposure.

Page 128: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

107

Delving deeper into the comprehensiveness checklist, the sub-themes within the dose optimization related

themes that are common to all of the strong jurisdictions include clinical justification, ALARA,

requirements for an administrative responsible person within an institution, requirement for radiation

protection or quality assurance committees and regular meetings and institutional diagnostic reference

level establishment. Interestingly, Kenya, as a weak jurisdiction with systematically higher dose levels,

does provide information in the legislation regarding clinical justification of exposures and ALARA-

related standards. A review of the radiation protection legislations showed that Kenya’s explanations of

the two sub-themes are less detailed than those of Council Directive 97/43/Euratom, which acts as a

model framework for the strong jurisdictions’ legislations. The extracted quotations from the respective

legislations are documented verbatim in Appendix I. The contrast in dose levels between Kenya and the

strong jurisdictions suggest that the quality and detail provided in the legislation play an integral role in

the level of success of the regulatory policy implementation. However, the inclusion of information for

both clinical justification and ALARA-related standards are recommended as a minimum requirement

since they were referenced by both weak and strong jurisdictions. Stronger regulatory approaches shall

also include information and standards for the establishment of radiation protection/quality assurance

committees and institutional DRLs.

Supplemental Documents

The percentage fulfillment of the responsible authorities, licensing and accreditation and results of non-

compliance themes for all of the analyzed supplemental documents was less than 4%. These themes are

designed to explain the strict oversight of CT facilities, which are inapplicable to supplemental documents

that do not have any independent legal authority. BC and Ireland’s supplemental documents were

excluded from the analysis for key themes because the legality invested in BC’s DAP standards and the

sole focus of Ireland’s Medical Council position paper on DRLs would skew the data.

The top six highest percentage fulfillments were, in order, general provisions, diagnostic reference levels,

technical requirements, operational requirements, emergency situations and event reporting and radiation

protection/quality assurance committee. The general provisions for supplemental documents are

important in ensuring that targeted users have similar levels of understanding. Three of the top six themes

are dose-optimization related, which agrees with the supplemental document’s purpose of providing

additional details for legal standards within a jurisdiction or recommending best clinical practices.

Page 129: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

108

Technical requirements in supplemental documents typically provide comprehensive procedures for

installation and maintenance of CT equipment. Meticulous details are discouraged for legislation

documents because legislations are designed to be flexible for adaptation as technologies and practices

evolve [98]. Supplemental documents do not require tedious multiple reviews by the legislative assembly

to be altered, so they provide an easier means to update the compliance standards for existing legislation.

Technical requirements are important in radiation protection of medical exposure because consistent

quality control across facilities ensure fully functional equipment are being used, which ultimately

increases confidence and safety of patients.

Focusing on the legislations and supplemental documents from strong jurisdictions (i.e. Australia and the

UK), it is evident that the supplemental documents are used to provide additional details that are not given

in the legislations. The dose-optimization related themes in the supplemental documents for both

Australia and the UK had comparatively higher percentage fulfillment than the corresponding

legislations. In terms of sub-themes that are dose optimization related, Australia and the UK supplemental

documents had many commonalities, including clinical justification for medical procedures, ALARA-

related standards, requirement for standard clinical procedures, review of new medical procedures, and

training programs and continuing education standards for radiology department personnel.

Standardization has been endorsed by the World Health Organization as a mechanism to improve patient

safety in other areas of healthcare such as reconciliation of medications, site identification during surgery

and communication during patient care handovers [147]. Translating this mechanism to imaging, the

standardization of CT protocols within a facility is expected to reduce information overload for the

technologists and minimize protocol selection errors. Furthermore, training programs and continuing

professional development standards also play an important role in dose optimization by ensuring

awareness for evolving CT techniques and technologies. It is recommended that specialized continuing

professional development education be available for each CT stakeholder, but the American College of

Radiology stresses the need for improvement of physics knowledge and awareness for patient dose among

the radiology residents and radiologists [148].

Interestingly, Texas did not have a representative document in this analysis because it has opted to use

legally binding Texas Administrative Codes (TAC), which are rules developed by the appointed state

agencies, to provide additional guidance to its Radiation Control Act [149]. The comprehensiveness of the

TACs was evident in the results in Section 6.1.1.1, which suggests that supplemental documents may be

unnecessary if the legislation provides sufficient information to guide users in achieving compliance.

Page 130: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

109

However, the ability to provide comprehensive legal documents may be unique to the organizational

system of TACs, which grants individual state agencies, such as the Texas Department of Health

Services, the power to publish legally binding rules under the Administrative Code Act [149]. The TACs

system significantly reduces the time required to produce or alter legal regulations since the rules can be

approved internally by a state agency without extensive review by the legislative assembly or an

appointed regulation-approval authority.

Ontario has also opted to use a legally-binding document (i.e. HARP Regulations) to further explain the

legal standards for radiation protection in medical applications, but the low comprehensiveness Ontario’s

publications contrast starkly with Texas’s highly comprehensive TACs. Regulations in Ontario are made

and altered under the authority of the Legislation Act, 2006 and so, require substantial discussion and

multiple reviews by the regulation-approving authority before entering into force [150]. For example, the

HARP Commission had reported recommendations for changes to the first version of the HARP

Regulations in June 2007 [151], but the amendments were not implemented until July 2011 [78]. This

lengthy alteration process to any form of legal document in Ontario has resulted in the HARP Regulations

being outdated and irrelevant to current standards of practice, which was shown in the Ontario’s low

percentage fulfillment score in the comprehensiveness assessment in Section 6.1.1.1.

It is, therefore, recommended that supplemental documents be developed to optimize the implementation

of legal standards if a jurisdiction cannot alter legally binding rules easily. The results of the

comprehensiveness assessment showed the sub-themes of standardized clinical procedures and standards

for continuing professional development education to be influential on radiation safety for patients and,

therefore, are recommended for inclusion in supplemental documents to strengthen dose optimization

policies.

6.3.1.2 Key Domains

Legislative Document Quality

Parts 2 and 3 of the evaluations using RACT 2 focused on quality assessment for the legislative and

supplemental documents. The domain scores of the strong jurisdictions ranged from 1.4 to 3.4. However,

the quality assessment of legislations for Australia and the UK do not accurately indicate the radiological

protection of medical exposures situation in the respective jurisdictions because of the presence of more

detailed supplemental documents for each country. Removing the scores for Australia (1.4) and the UK

(1.8), the legislative quality scores for the strong jurisdictions ranged from 2 to 3.4. Contrastingly, the

score for Kenya, a weak jurisdiction, was 1.8.

Page 131: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

110

The notable difference in the comparative domain scores for the strong and weak jurisdictions was for the

rigor of compliance domain, which measures the extent of work required to achieve compliance with the

legal standards. A highly rigorous standard to achieving compliance provides continuing monitoring and

supervision measures to measure the progress of lack thereof in legislation implementation at the

institutional level, identify and address problems of possible risks and take corrective actions in a timely

manner [102]. The rigor of standards can be measured by the amount of evidence that must be presented

to the supervisory authority and the available oversight measures implemented by the authority. The

availability of oversight measures by a supervisory authority can improve the confidence of patients using

these CT facilities.

The outcomes of compliance domain also appear to be important in the design of legislations, as the

highest overall average scoring theme by a slight margin of 0.1 on the 5-point Likert Scale. However,

both the strong and weak jurisdictions paid specific attention to this domain. Strict outcomes of

compliance declared in the legislation act as a pre-cautionary measure for CT facilities to prioritize

patient safety by ensuring compliance with the legal standards. Regulations with strict consequences

provide arguably the best incentive to initiate the creation of patient safety cultures, but overly expansive

and unrealistic standards can hamper flexibility and innovation [152]. Furthermore, it may diminish a co-

operative relationship and cause tension between institutions and the supervisory authority. A balance of

support from the authority and severe sanctions is, therefore, recommended to encourage the creation of a

safety cultures. Compliance standards and the associated consequences of non-compliance were shown to

be key domains that impact legislative quality, which is expected since radiation protection legislations

are generally drafted to ensure patient safety is considered and prioritized at each institution.

Supplemental Document Quality

The analysis of supplemental document quality revealed that the two highest average scoring domains are

clarity of scope and purpose and instructive quality of writing. Much attention is paid to ensuring clarity

of scope and purpose by each jurisdiction because this domain defines the level of comprehension from

targeted users have when reviewing the document. A strong tone for the entire document is established if

this domain is performed well. Secondly, it is no surprise that ample attention has also been paid to the

instructive quality of writing because supplemental documents are designed to provide detailed

procedures to help facilities achieve compliance. The level of detail in these procedures affect the

actionability of the recommended action plans, and influences the implementation of the legal standards

within a facility.

Page 132: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

111

The lowest average score in the supplemental document quality evaluation is 1.71 for India. India’s

extremely poor performance in the adaptability domain is prominent since only two 0s were awarded in

Part 3 of the RACT 2 evaluations. Adaptability is reflected in the provision of options for different

situations and alternative action plans for varying institutional workflows. This is important because it

provides realistic expectations and achievable guidance to ensure compliance with legal standards. The

high-scoring supplemental documents (i.e. Australia and IAEA) contrasts starkly with the low-scoring

documents (i.e. India and Ireland) in the integration of inter-professional perspectives domain, which

suggests that this domain is important in defining the supplemental document quality. Consideration for

the needs of each stakeholder group can increase credibility of the document by showing

comprehensiveness. Furthermore, implementation is expected to be smoother if every stakeholder is

included.

From the key domains analysis for supplemental documents, strong performance in the instructive quality

of writing, adaptability and integration of inter-professional perspectives domains are expected to

positively affect the implementation of recommended practices and legal standards.

6.3.2 Need for Regulations

One of the pressing questions in this study was to determine if involvement of legally authoritative bodies

are required to optimize doses. Japan was selected for inclusion of this study due to its unique lack of

regulations for CT facilities. Despite being one of two countries that have accelerated health spending

since 2009 and having the highest number of CT scanners per capita [70], Japan has opted to not focus on

radiation protection of medical exposures for patients. The poor prioritization of Japan’s healthcare

system is evident in the country’s systematically higher proposed DRLs compared to other jurisdictions

with official or proposed DRLs, which suggests that Japan has an overall higher dose distribution since

the DRLs were defined as the 75th percentile value of the distribution for each exam type. The results of

the dose levels comparison offers preliminary evidence that regulatory approaches are required to make

certain that CT facilities are aware of the risks associated with high radiation doses. CT facilities must

first be aware of the risks before action plans can be designed to manage CT radiation dose. Further

comparison studies, with standardized definitions for exam types and data collection and analysis

methodologies, are required to strengthen the finding that jurisdictional regulatory approaches are

mandatory in CT dose management.

Page 133: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

112

6.3.3 Current Status of Ontario

The relative status of Ontario’s radiation protection program for medical applications was another

question that this study embarked to answer. The Euratom member states, which modeled their

legislations in accordance with Council Directive 97/43/Euratom, exhibited systematically lower dose

levels than the other jurisdictions in the study. Japan, on the other hand, did not have regulations targeted

for ionizing radiation exposures from medical applications and it emerged with higher dose distributions.

The message is clear. It is evident that there is a need to establish specific regulations for CT dose

management if doses are to be optimized in an attempt to improve patient radiation safety.

Ontario’s legislation is lacking in comprehensiveness, as shown in the low overall percentage fulfillment

of 21.12%. While Ontario provides sufficient information for the licensing and accreditation and results

of non-compliance themes, this is inadequate to encourage prioritization of dose optimization at the

institutional level. Kenya, who also had systematically higher proposed DRLs as a result of high dose

distributions, also had high percentage fulfillments in the licensing and accreditation and results of non-

compliance themes. If Ontario is to ensure application of the ALARA principle across CT facilities, it

needs to formulate the radiation protection legislation to mimic the strong jurisdictions’ legislations. This

involves the inclusion of information for more dose-optimization related sub-themes, such as a legal

clause for clinical justification, ALARA-related standards and specific training programs and continuing

education standards for CT stakeholders.

The legislation quality of Ontario as a whole warranted an average score of 2 in Part 2 of the RACT 2

evaluations. The below average scoring domains for Ontario were clarity of legislative scope and the rigor

of expectations. The legislative scope should detail the application of the legislation and explain the need

that the legislation addresses. Clear, well-written legislative scope is important in setting the tone and

ensuring that targeted users have a similar comprehension of the document. The rigor of expectations is

an influential factor in legislation quality because highly rigorous standards result in higher quality

legislations that have better success with implementation, which translates into increased awareness for

dose optimization. Currently, the licensing requirements for the HARP act are technically focused and

mainly associated with the functionality of the CT equipment. While technical requirements are

important, the Euratom member states have shown that oversight from the supervisory authority for dose-

optimization related standards have been beneficial in ensuring that dose distributions are comparatively

lower than their jurisdictional counterparts without dose-optimization related standards.

Page 134: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

113

6.3.4 Limitations of Evaluation

There are some potential limitations that should be considered when reviewing the analysis of the

relationships between the RACT 2 evaluations and general dose trends. Firstly, the highest scoring

jurisdiction in the comprehensiveness assessment and legislative quality assessment, Texas, did not have

any published dose data so Texas was excluded from the relationship analysis. This hindered the

extraction of key themes and domains because the high-scoring aspects of the Texan legislation could not

be validated as having an impact on dose levels. Furthermore, the exclusion of Texas from the

relationships analysis limited the opportunity to validate RACT 2 and its application in comparatively

evaluating jurisdictional radiation protection documents for medical exposures. Supplemental documents

were also selected based on the stated relevance from jurisdictional representatives, which suggests that

additional supplemental documents may be available to enhance the RACT 2 analysis further. A

relationship analysis between Texas dose levels and the RACT 2 scores and an expanded criteria for the

inclusion of supplemental documents will likely enhance the evaluations.

The evaluations were also limited by the lack of inter-rater reliability since only one reviewer was

available for the RACT 2 evaluations due to the limited financial and human resources for the study.

Inter-rater reliability strengthens the evaluations by ensuring consistent scoring in the independent

evaluations and that the interpretations of the rating scale are not drastically different. It is, therefore,

recommended that future assessments using RACT 2 be performed by a minimum of 2 reviewers to

assure consistent interpretation of the instrument. High inter-rater reliability can validate the application

of RACT 2 for radiation protection document evaluation.

Inherent limitations of RACT 2 also emerged through the analysis. The overall approaches of the UK and

Australia could not be compared due to the categorization of document types for the evaluation. A

method to reconcile the results of each document type’s evaluations is required to provide a more accurate

overview of the overall jurisdictional regulatory approach. The evaluation was also limited by the use of

the 5-point Likert Scale in Parts 2 and 3. While the rating scales for each criteria provided clear and

unambiguous guidance, the Likert-Scale use resulted in inconclusive results for the quality analyses.

Significant difference between the scores were not shown, and only the jurisdictions at both ends of the

extreme (i.e. lowest and highest scores) for each evaluation were evident. The critical differences in

jurisdiction with similar regulatory frameworks could not be accounted for. Further refinements to RACT

2 that account for these limitations are recommended.

Page 135: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

114

6.4 Summary of the Jurisdictional Evaluations

The jurisdictional radiation protection publications in Table 5 were evaluated using RACT 2, and the dose

data from each jurisdiction were analyzed for trends and patterns. Relationships between general dose

levels and the evaluation results from RACT 2 were established to offer preliminary insight into the

regulatory approaches that are most successful in CT dose management. The similar approaches by the

Euratom member states were shown to result in systematically lower dose distributions in relation to their

counterparts who also have comparable dose data. Japan and Kenya had comparatively high proposed

DRLs, which offered preliminary evidence that dose optimization-related content in the regulations are

mandatory to the prioritization of dose optimization at the institutional level. In particular, clinical

justification of medical exposures and ALARA-related standards should be made explicit in the

legislation to strengthen CT dose management. Legislative quality and supplemental document quality

assessments revealed that the clarity of scope and purpose are important in setting the tone. Furthermore,

legislative quality is dependent upon the rigor of expectations and the outcomes of non-compliance, while

the instructive quality of writing is influential in the quality of supplemental documents. There are several

inherent limitations to the dose levels comparison and the relationship analyses that should be considered.

Future work is needed to refine RACT 2 and to offer more accurate correlations between the dose levels

within a jurisdiction and the regulatory approach undertaken.

Page 136: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

115

7 Strategy Development for Radiation Protection of CT in

Ontario

The final specific objective was to develop a strategic framework for Ontario’s regulatory approach that is

both achievable and comprehensive. Qualitative interviews with jurisdictional representatives,

radiologists and medical physicists provided insight into the possible dose optimization approaches that

could enhance Ontario’s radiation protection for medical exposures program. A model for Ontario’s

regulatory structure was also designed. The recurring highlights and key elements from the jurisdictional

analyses using RACT 2 were incorporated into the recommendations for changes to Ontario’s radiation

protection publications. The recommended regulatory approach to dose optimization in Ontario was

selected after the evaluation of factors that should be considered in the design of new regulatory structure.

7.1 Expert Interviews with Jurisdictional Representatives and CT

Stakeholders

Qualitative interviews were conducted with jurisdictional representatives to learn more about their

experiences with implementation of new policies. Radiologists and medical physicists were interviewed

to better understand their needs, priorities and concerns in new dose optimization standards. Family

practitioners were identified as stakeholders because they are actively involved in the referral process for

diagnostic CT exams, so interviews with family practitioners were also planned.

7.1.1 Family Practitioners and the Referral Process

The workflow of diagnostic CT exams mostly starts in the office of family practitioners. The referral

processes for diagnostic exams have garnered interest in patient radiation protection research as CT

utilization has increased. Dose management for CT involves applying the right dose, accounting for the

specific patient attenuation and the specific diagnostic task [44]. The American College of Radiology has

developed evidence-based guidelines to aid family practitioners in selecting the appropriate imaging test

according to the clinical indications [44]. The focus on appropriateness in CT diagnostics in literature

provided the basis for the intended semi-structured interviews with family practitioners. Approval was

obtained from the University of Toronto’s Research Ethics Board as Protocol #30369.

7.1.1.1 Interview Questions Generation

The semi-structured interviews were designed to elicit more information regarding:

1. The awareness of the clinical applications for possible diagnostic imaging modalities

2. The decision-making process for medical imaging diagnostics referrals

3. Perceived accessibility to guideline materials

Page 137: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

116

4. Potential solutions that may be useful to improve the current referral process

A fundamental qualitative descriptive approach, as described by Sandelowski [81], was undertaken to

formulate open-ended interview questions (Appendix J).

7.1.1.2 Study Population and Recruitment Strategy

In order to be included in the study, participants must be practicing family practitioners, interact with

patients regularly and have experience in referring patients for medical diagnoses. The participants must

be able to read, write and understand English and be willing to participate. Study participants were to be

recruited from the pool of faculty and staff affiliated with the Department of Family and Community

Medicine at the University of Toronto, such as family practitioners from the following hospitals,

Markham Stouffville, Mount Sinai, North York General and Trillium Heath Partners.

The semi-structured interviews with family practitioners were designed to employ a maximum variation

sampling strategy, which involves the purposeful selection of participants with diverse characteristics and

aims to capture the central themes that cut across a great deal of variation [153]. A local co-ordinator, Dr.

David Tanenbaum of Mount Sinai Hospital, was contacted to identify potential participants. Potential

participants were to be informed of the study via e-mail. Interested individuals would be provided with

more information and a consent form.

7.1.1.3 Recruitment Results and Discussion

When the local co-ordinator was contacted via e-mail, it was revealed that there was an ongoing

Diagnostic Appropriateness Project (i.e. DI-App) with University Health Network’s Joint Department of

Medical Imaging Office of Strategy Management Team. The project’s estimated completion date is

November 2015 and was well underway. Semi-structured interviews were, therefore, not conducted with

family practitioners because the parallel DI-App project had an analogous purpose. DI-App aimed to

align evidence-based imaging guidelines with the needs of family practitioners and to conduct a

feasibility analysis to identify the most effective methods for dissemination, education and adoption of

guidelines into clinical workflow [154]. A final report for DI-App is scheduled to be submitted to

Ontario’s Ministry of Health and Long-term Care in November 2015. Hopefully, the improved evidence-

based referral tool can be integrated into the current clinical referral workflow.

7.1.2 Expert Interview with CT Stakeholders

Successful uptake of new dose regulatory policies was hypothesized to require the co-operation of

resident radiologists. Medical physicists were also interviewed because of their prevalence in the

radiological practices in the other jurisdictions, including Switzerland, Germany and Australia. Semi-

Page 138: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

117

structured interviews were selected as the data collection method because they are useful in providing

insight into the experience and attitude of the interviewee [155]. Furthermore, the interviews are expected

to elicit issues or concerns of each stakeholder regarding changes to the radiation protection for medical

applications regulatory structure. Semi-structured interviews with radiologists and medical physicists

were conducted under the approval of University Health Network’s Research Ethics Board for Protocol

14-7902.

7.1.2.1 Interview Questions Generation

Open-ended questions were generate through a fundamental qualitative descriptive approach, as described

by Sandelowski [81]. Sample questions are detailed in Appendix K. The questions focused on the

following topics:

1. Awareness of cancer risk and CT radiation dose correlation

2. Needs and priorities in CT imaging

3. Perceived availability and quality of radiation dose-saving tools

4. Potential solutions that may be useful in ensuring adherence to the ALARA principle

7.1.2.2 Recruitment Strategy

In order to be included in the study, potential participants must be working healthcare professionals and

active members of an institutional radiology team. They should have updated knowledge of CT scanning

parameters, platforms and available dose-saving technologies. The potential participants must be able to

read, write and understanding English and be willing to participate. The participants did not receive any

reimbursements of compensation as it is expected that the formulation of dose management regulations in

Ontario will improve patient safety, which is ample incentive for healthcare professionals to participate in

this study.

The semi-structured interviews with CT stakeholders employed a maximum variation sampling strategy

to select participants with diverse characteristics. Potential participants were identified through two

methods. Firstly, local champions for dose optimization in Toronto were identified through the

recommendation of Dr. Larry White, Radiologist-in-Chief of the University Health Network/Mount Sinai

Hospital/ Women’s College Hospital Joint Department of Medical Imaging and the recommendation of

Ms. Catherine Wang, Executive Director of the Joint Department of Medical Imaging. Secondly,

jurisdictional representatives that were interviewed (Table 6) provided recommendations of radiologists

or medical physicists that have proven interest in furthering dose optimization efforts.

An e-mail explaining the purpose of the study, with an attached consent form, was sent to each potential

interviewee. If the radiologist or medical physicist was interested, an interview date and time was set at

Page 139: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

118

the interviewee’s convenience. Participants were recruited continuously until time constraints did not

allow for additional interviews.

7.1.2.3 Study Population

Two medical physicists and four radiologists participated in the semi-structured interviews. Efforts were

made to diversify the jurisdictions where each interviewee worked. The semi-structured interviews with

radiologists garnered more information than expected, despite only having four participants, because each

of the radiologists practised in more than one of the selected jurisdictions. Contrasting experiences of

working under different radiation protection regulatory structures provided unique insight into the

benefits and drawbacks of varying dose optimization approaches. The perspectives of medical physicists

were abundant because many of the jurisdictional representatives listed in Table 6 are medical physicists

by background. The common goal to further dose optimization yet different career paths of the medical

physicists provided interesting insight into the perceived role of medical physicists in dose optimization

strategies. Table 22 summarizes the role of each interviewee and their practice experiences.

Table 22: A summary of the CT stakeholders that participated in the semi-structured interviews

Participant Role Institution Type Practice experience (Current jurisdiction, past

jurisdiction)

PR-1 Radiologist Academic Ontario, Germany

PR-2 Radiologist Academic Ontario, UK

PR-3 Radiologist Academic Ontario, UK

PR-4 Radiologist Academic Switzerland, Ontario

MP-1 Medical physicist Mixed Ontario

MP-2 Medical physicist Community British Columbia

7.1.2.4 Setting and Procedure

Three of the interviews with participants were conducted in person, while four of the interviews were

conducted over the phone. Each interviewee should have read the consent form prior to the interview

date. The purpose and methods of the study were explained before the start of the interview. Any

questions the interviewee had were answers. Five of the six participants provided verbal consent before

the start of the interview, whereas one participant completed the written consent form. Once consent was

received, each interview was audibly recorded using two methods: handheld audio recorder and a laptop

computer. Typewritten notes were also recorded on the laptop computer. Near the end of each interview,

consent was obtained to send any additional questions via electronic means if any missing information

was subsequently deemed important.

Page 140: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

119

7.1.2.5 Data Analysis

Each audio recording was transcribed for data analysis purposes. The interview information was mainly

decided into two parts. Part 1 of the interview discussed the current status of dose management within the

jurisdiction where the interviewee worked. Part 2 focused on the discussion of considerations for potential

dose optimization strategies. The qualitative data from both parts were analyzed for recurring themes

using the described qualitative content analysis procedure from Sandelowski [81]. Important factors that

emerged were analyzed for meaning in the context of the discussion [81]. The transcripts were reviewed

line by line, and the recurring themes that emerged over the course of the analysis were assigned using

Microsoft Office. As the coding framework was developed, the transcripts were reviewed again for any

new themes that may have emerged. The coded themes were analyzed, relationships were identified and

patterns were described.

7.2 Analysis of Possible CT Dose Management Strategies

Jurisdictional regulatory approaches, as described in the analyzed radiation protection publications, were

evaluated. Additional information regarding each approach was extracted from the semi-structured

interviews. Part 2 of the interviews with jurisdictional representatives (Table 6) provided insight into the

experience of implementing and monitoring the progress of the approaches, whereas the perspectives of

institutional stakeholders garnered from the interviews with radiologists and medical physicists (Table 22)

offered unique insight into the uptake of the regulatory approaches at the institutional level. A

combination of these contrasting perspectives provided sufficient information for analysis of the potential

benefits and drawbacks of each approach.

7.2.1 Diagnostic Reference Levels

DRLs were first introduced internationally by the International Commission of Radiological Commission

(ICRP) in 1996 “as a form of investigation level to identify usually high levels, which calls for local

review if consistently exceeded [156].” They are designed to help avoid radiation dose that does not

contribute to the clinical purpose of a medical imaging task in diagnostic radiology and nuclear medicine

by allowing comparisons between the DRL and the mean or other appropriate value observed in practice

for a suitable reference patient group or phantoms [156].

Although they were first officially recommended by the ICRP in 1996, analogous concepts existed in

other jurisdictions. For example, the Conference of Radiation Control Program Directors of the U.S.

developed patient exposure guides, which are non-regulatory guidance values tied to specific technique

factors (e.g. patient thickness, film speed) [156]. Moreover, the representative from Public Health

Page 141: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

120

England explained that DRLs “were sort of invented here (in England).” In fact, England’s first CT dose

survey was conducted in 1989 by the National Radiation Protection Board (NRPB) and the representative

from the UK described the resulting data as “a wide distribution with some (doses) that were very, very

high.” The purpose of the dose survey, according to the interviewee from the UK was to “identify (a) sort

of normal data value (and to provide feedback to) hospitals, (that) say ‘look, you are massively above the

highest level’. Rather than to present something like the mean value, which would have skewed the data,

they came up with something which we call the third quartile.”

The best practice of setting the DRL as the 75th percentile of the dose distribution is widely accepted and

implied by the IAEA as the organization explains that DRLs are “helpful in identifying potentially usual

practice (the highest 25% of typical doses) [100].” However, legislations that mandate the establishment

of DRLs, such as the Council Directive 97/43/Euratom that forms the backbone of many European

countries’ legislations, simply define DRLs as “dose levels in medical radiodiagnostic practices, or in the

case of radiopharmaceuticals, levels of activity, for typical examinations for groups of standard-sized

patients or standard phantoms for broadly defined types of equipment. These levels are expected not to be

exceeded for standard procedures when good and normal practice regarding diagnostic and technical

performance is applied. [68]”

7.2.1.1 Establishment of Official DRLs

Many of the jurisdictional representatives were eager to provide advice on how to establish official DRLs.

Traditionally, dose distributions were collected via dose surveys by either an appointed research group or

the supervisory body themselves. Some surveys are mandatory, and data from all CT facilities included in

the distributions:

Representative from Switzerland: “We are publishing them (DRLs), but we are not doing the

surveys ourselves; we have the contracted universities doing that […] it is very time consuming

for all sites.”

Representative from Germany: “The so-called medical authorities that I mentioned, they collect

all the exposure data. As I mentioned, they ask regularly for each x-ray device every 3 years.

They ask for exposure data (which) means they ask them ‘please send me all the exposure—all

the images—for this device (type) between May 1st and May 10th.”

Other jurisdictions have voluntary surveys. The drawback of voluntary surveys is the lower response rate,

which results in smaller datasets in the establishment of dose distributions.

Representative from the UK: “It is in regulations that they measure them for their local set-up,

but it is not in the regulations for them to supply data to us. It’s only in the regulations that they

compare to their local doses to whatever the national doses are available. […] We only had 30%

of hospitals sending us data for our latest CT survey, whereas it was 80% for our first survey.”

Page 142: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

121

Representative from Australia: “We have been doing the CT surveys since 2011. […] We are

hoping to see a big increase in uptake of people doing our DRL survey that we provide. We have

done a long survey that people can do to send data in. Umm, it’s not the only survey that they can

do, but our survey—they’re free—and we have only got about a 30% uptake of all the filling in

the CT space.”

Due to the extensive requirements for financial resources and time-consuming nature of traditional dose

surveys, some of the jurisdictions have begun to explore the application of technology to collect dose data

from CT facilities. These technological systems are expected to collect doses automatically, which will

relieve the burden for financial resources and substantially reduce the amount of work required to

organize the data. The ease of the data collection and analysis is anticipated to encourage more frequent

reviews and updates to official DRLs.

Representative from Switzerland: “Now in the future, with all of these dose management software

tools coming up, those where maybe you have to enact them on the PACS System, which are

really collecting the dose data. We are looking forward to have them more regularly updated.”

Representative from Ireland: “Our health services recently purchased a national PACS system

which is being rolled out across hospitals. So, now dose surveys, especially in the areas of CT,

would get a lot easier because you don’t need manual data collection. […] Well, the hope is that

all the responsibilities (i.e. data management and updates of DRLs) will be delegated to one

person on a fulltime basis.”

7.2.1.2 Institutional DRLs

The IAEA explains that “national DRLs are not optimum doses […] national DRLs are intended to

promote awareness, dose audit and comparison as the basis for improving patient radiation protection,

with an implied maintenance of diagnostic quality.” A comparison between the facility-specific dose

levels and the national DRLs is, therefore, required to understand the relative status of the CT facility’s

dose optimization efforts. Many jurisdictions recognize the importance of dose level comparisons, and so,

have mandated the requirement to establish institutional DRLs. The local DRLs in relation to the national

DRLs provide a means for some jurisdictions to measure compliance.

Representative from Australia: “The hospitals produce what’s called facility DRLs […] we

provide a report back to the individual hospitals comparing their practice reference levels with

the national reference levels. And basically, align on a graph of where they fit. [...] we have sort

of with the 75th percentile line, we say, ‘well okay, your practice is good, you are below that.’ If

it’s above, then you need to instigate some optimization process to bring it back.”

Representative from the UK: “If you go into a radiology department, they will talk about the

DRLs because they have to have them and they have to have local ones. The local ones don’t

have to be the same as the national ones. But um, when they have them, they have to make

reference to the national ones.”

One jurisdiction had realized that the infrequency of updates and generalization of exams has resulted in

the official DRLs being irrelevant to the practices of some academic centres that perform more complex

Page 143: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

122

CT scans. Switzerland has, therefore, encouraged the establishment of stricter and more relevant local

DRLs that can be used as comparative levels in place of adherence to the official DRLs.

Representative from Switzerland: “There are big hospitals like the university hospitals actually

working with locally defined DRLs, which are a lot below the national ones. The whole idea is to

optimize what is possible. […] national DRLs are for mainstream, so if you have specialties, the

national DRLs doesn’t help you very much, so you define your own DRLs in discussion with the

Federal Office”

Institutional DRLs provide a means to measure compliance, while offering a flexible approach to

legislated DRL standards. They are, therefore, recommended increase adaptability of legislation by taking

into account the varying levels of technical expertise, age of equipment and level of complexity in CT

exams performed in different CT facilities.

7.2.1.3 Advisory, NOT Limits

The potential misuse of DRLs was also a popular topic of discussion in the semi-structured interviews

with the jurisdictional representatives and radiologists. There is a common misconception among targeted

users unfamiliar with the concept that DRLs are upper limits for specific exam types. However, the

numerical value for the DRL is simply the 75th percentile of the typical dose levels within a jurisdiction or

facility. By definition, 25% of the doses are always going to exceed the established DRLs, which suggests

that DRLs should not not be applied as strict legal limits.

Representative from IAEA/ICRP: “There are no dose limits, but there are reference levels. They

are not limits. Limits are regulatory, they are mandatory, they have a legal place. Reference

levels do not have a legal place. So, they can be exceeded and without any problem.”

There is consensus from the jurisdictions with official DRLs that the reference levels can be exceeded

when required by the specific patient indications or situation. DRLs are established with data from a

standard patient group (i.e. specific weight and height range) or standardized phantoms, so thicker

patients are inevitably going to require higher radiation doses to obtain a diagnostically

Representative from Germany: “I think it’s one of the biggest problems. The relation between the

DRLs and the reference man, reference women. […] A lot of people are not the reference man

and are heavier.”

Representative from the UK: “It’s (the use of DRLs) more about identifying if you are an outlier

[…] if you are above it, you do try and get down below it. But if there is a good reason why you

are above, then—like you do complicated procedures or something—then that’s fine.”

This misconception can result in resistance from the radiologists and other targeted users of DRLs, so it is

essential to ensure that there is understanding among the intended users that DRLs are not meant to be

controlling or legal limits. They are simply advisory levels.

Page 144: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

123

Representative from Australia: “That was one of the issues that the radiologists felt that we were

trying to set a limit, rather than a level. So they initially were quite reluctant to go down the path

of this work. […] The word ‘DRL’ and the concept of DRL became more and more accepted. I

would say, in most cases people at least now have heard of DRLs and know what it means, and

know it’s not a limit.”

7.2.1.4 Low doses are just as dangerous

While the focus of DRLs by targeted users and jurisdictions have been on unusually high doses above the

75th percentile mark, there is concern that the drive for lower doses will result in excessively low doses.

Dose optimization is based upon the ALARA principle, which recommends the use of the lowest possible

dose for sufficient image quality to make accurate diagnoses. Furthermore, insufficient quality of images

may lead to repeat scans and the cumulative dose from these scans will lead to greater radiation exposure

for patients compared to one scan that used sufficient dose for a diagnosis.

Representative from the UK: “You don’t want to reduce it to nothing. You want to reduce it only

to the extent that you still get a diagnostic image quality. […] the medical physicists and the

radiographers (in the UK) are waking up to, ‘oh, we don’t want to go too low.’”

Radiologists and medical physicists also fear the implications of the blindly pushing for lower doses,

without considering the need for a balance of dose and image quality.

MP-1: “And then I also set a lower diagnostic reference level at the 10th percentile and

institutions that are significantly below that, they are probably using too little dose and flag them

for follow up.”

RP-1: “I am worried to be part of the message that focuses on dose reduction instead of the

information you get from what dose and leave the damage and dose to the society as a different

point.”

7.2.1.5 Alternatives to DRLs

Due to the limitations of DRLs, organizations and independent research groups have been investigating

alternative methods to provide more effective guidance for routine exam types. One of the most

recognized limitations to DRLs is its inapplicability to non-standard sized patients. Another concern is the

extensive resources required to establish official DRLs, which makes this regulatory approach difficult to

implement in jurisdictions with lower health spending and insufficient resources. Furthermore, the

difference in the capability of the CT scanner (i.e. number of slices performed by the MDCT) results in

radiation dose variance for the same exam types. Alternative methods that can address these limitations

may be more effective than the current standard approach of DRLs.

Bottom-Up Approach

A selection of standardized protocols is provided for specific exam types within a jurisdiction. It is called

bottom-up because it uses existing patient scans to develop a large database of possible protocols. The

Page 145: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

124

standardized protocols are categorized based on weight, clinical indication, and image quality.

Furthermore, guidance is provided for adjustments based on scanner type to achieve uniformity in the

dose and image quality for routine techniques. Some interviewees were supporters of this approach.

RP-2: “And you know where the technique is different, be it slices, which reconstruction, be it kV,

mA, you are going to get a different radiation dose, so there is a lot of work to be done on the

protocol piece. […] if there is published data to say […] what’s the best protocol for a routine

chest (reading)? We want to make sure the things we look at a regular chest CT are well picked

up, but what would be the slice thickness and reconstruction (module)? And then secondly, what

would be the level of image noise? […] you can actually then have some uniformity there, and

then you automatically adjust for the type of scanner.”

Representative from IAEA/ICRP: “So, there is something which does not require infrastructure at

the national level […] something which any clinic can do, any hospital can do, and they will

select the images which are acceptable and then find the doses and find the mean or median

value and say, ‘oh, my accepted reference dose is this much.”

Rehani conceptualized the acceptable quality dose (AQD), which furthers the two ideas described by the

interviewees by sub-dividing the standardized protocols into weight categories [157]. Information

regarding the protocols for specific clinical indication, patient weight and a rating for image quality is

collected over a specified time period [157]. The image quality rating is given by radiologists who are

provided with a list of features that should be identifiable in the image [157]. Over time, a database of

“acceptable image quality” images for routine exam types are developed. This approach can be taken at a

local level. However, one of the radiologists interview explained that uniform protocols across a

jurisdiction would, perhaps, be more beneficial than an institutional-based database, which is possible for

jurisdictions with image repository servers.

RP-2: “The ultimate priority would be to set this range of probably CTDIvol and effective dose for

various standard procedures. The way could implement that, as I say, is having agreed uniform

protocols across hospitals. […] that kind of information sharing, image sharing, would be useful.

Now with this PACS system, where we are all sharing stuff. […] it’s according to LHIN (local

health integration network), but they are in a group so that CT and other studies all get sent to a

server repository.”

Size-Specific Dose Estimates (SSDE)

The other proposed alternative is SSDE, which accounts for patient size, in the development of reference

levels. Traditional DRLs are inapplicable to thicker people, so the guidance from DRLs is limited.

Germany is one of the jurisdictions that have taken an interest in SSDE.

Representative from Germany: “We have a lot of thicker people over here, and for those people,

the diagnostic reference levels cannot easily be considered. So, that’s a problem. A future task for

us will be certainly to publish diagnostic reference levels for different weights, or the so-called

SSDEs.”

The need for size-specific dose estimates was echoed by a radiologist, who said:

Page 146: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

125

RP-3:” An area for future development in adult practice is the adaptation of technical

parameters according to patient size. This principle is now widely applied to pediatric CT, but

logically, should be extended to adult practice.”

SSDEs attempt to incorporate patient size into the calculation of patient dose by developing conversion

factors that can be applied to the displayed CTDIvol to estimate patient dose [158]. Currently, DRLs are

often developed by collecting information from the display console of CT scanners, which provides the

scanner output in CTDIvol and is not representative of the patient dose. Furthermore, the scanner output is

calibrated to the standard phantoms and so, using the displayed CTDIvol or DLP as patient dose could lead

to the underestimation of dose levels by a factor of 2-3 [158]. The American Association of Physicists in

Medicine details several studies that undertook different data collection and analysis methodologies, and

proposed final conversion factors based on the combined results of the studies [158].

7.2.2 Important Actors in Radiation Protection of Medical Exposures

Three of the major players in radiation protection of medical exposures are medical physicists,

radiologists and technologists. Their roles and duties, as perceived by the interviewees, are discussed.

Despite the division of duties and responsibilities among the CT stakeholders within a radiology team,

there is a need to involve all perspectives in any dose optimization project.

7.2.2.1 Medical Physicists

The role of medical physicists within a radiology team at a facility is, perhaps, the most contrasting

between interviewees. Depending on the training of the interviewee, their perceptions of the medical

physicists and their potential contribution to radiation protection in CT dose management varied.

Jurisdictional representatives who have training in medical physics spoke highly of medical physicists on

the radiology team, but their perspectives are biased. The expressed attitudes are also self-reported

perceptions. For example, Switzerland has mandated medical physicists to be available at every CT

facility. When asked about the response of the CT facilities, the representative from Switzerland who has

a medical physics background was positive in the response.

Representative from Switzerland: “A lot of smaller institutions didn’t have a medical physicists.

[…] They didn’t have the money and they didn’t see the purpose. […]The medical physicists are

skilled. They (the CT facilities) are getting used to it. They are used to working with them. […]

Many hospitals that were angry at the beginning will now never get rid of their physicists

anymore because they see how much improvement it is to have them around.”

Other jurisdictional representatives explained that medical physicists are the most qualified personnel to

drive dose optimization in the facilities. Their education and background also make them ideal candidates

to take corrective actions in situations of unusually high doses.

Page 147: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

126

Representative from IAEA/ICRP: “If there are medical physicists who can be trained, who can be

accustomed, who can be oriented, then they can carry the message forward because this is their

bread and butter—radiation dose management.”

Representative from Australia: “I think one of the things that this (DRLs) is highlight is the need

to have more and more medical physicists out in the clinical world. […] they are pretty up to

speed with DRLs and probably pretty well up to speed with what needs to happen to optimize

from a technical side. […] they are exceeding the national DRLs, and then, we give them the

recommendation as to what they need to do. SO, as part of the recommendation, we just say they

need to seek support from a medical physicist.”

Medical physicists who are practising at the institutional level are adamant about the need for medical

physicists to be represented on a radiology team. The common perception is that radiologists are focused

on the clinical aspects of their role (i.e. reading images) and so, medical physicists become the designated

co-ordinator for dose optimization problems. Furthermore, technical problems with CT equipment are

also thought to be best addressed by medical physicists who are knowledgeable in physics.

MP-1: “A medical physicists is integral in this process. In my experience, a lot of the radiologists

are busy reading images. They get paid to read images. And unless there is something worked

into the payment scheme so they can have time and be willing to dose optimization, they really

don’t bother. […] the best person for this optimization is really a medical physicist.”

MP-2: “I could only tell from my own experience here (at the institution) is that it speaks to the

advantage of having medical physicists that know what they are doing and working with people.

Even though I am not there all the time, but if they have a problem, they will come to me and I

will help them out.”

The perspectives of radiologists regarding the potential contributions of medical physicists to dose

management efforts were contrasting. One radiologist has accepted medical physicists as a member of the

radiology team, and therefore, play a role in dose optimization projects.

RP-3: “Overall, the process of designing, introducing and maintaining protocols aimed at dose

reduction is a complex effort requiring input from many sources—including radiologists, CT

technologist leads, application specialists from the vendors, and medical physicist.”

However, two of the radiologists, who are actively involved in institutional dose optimization programs,

are underwhelmed by their experiences with medical physicists. The general consensus between these two

interviewed radiologists is that the medical physicists do not add knowledge to the dose optimization

programs. The radiologists claim the role and responsibilities of the medical physicists can be performed

by the radiologists themselves.

RP-1: “We do have medical physicists (at the institution), but in that committee (dose

optimization committee), I usually fulfill the role for dose reduction. We have a medical physicist

here who, technically speaking, should do part of my job. […] I don’t mind medical physicists. I

just don’t know how much this person would have to do because once you have a clear

understanding of what we are trying to achieve, the role of a medical physicist is limited. […] but

Page 148: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

127

let’s assume it’s a private practice or a smaller community hospital where there is no physics

knowledge around, then I think a physicist should be at least consulting once in a while.”

RP-4: “I think if they are very well-knowledgeable, if they understand really the need of the

radiologists, then I think they can be quite helpful. But I think some of the work can be done by

the radiologist. I would say medical physicists, they are okay. […] some people think maybe they

are a little too important.”

In Ontario, the more pressing issue from the perspectives of medical physicists is the HARP Act and

Regulations’ exclusion of medical physicists from acting as the radiation safety officer in radiological

facilities. Current practising medical physicists at the institutional level state this limitation as the reason

that Ontario facilities do not have very many medical physicists who are actively helping in the dose

optimization efforts. Furthermore, they are concerned about future dose optimization efforts.

MP-1: “Something that the Canadian Organization of Medical Physicists have been trying to

work with the government (is) to make changes to HARP. One big problem is that medical

physicists aren’t allowed to be radiation safety officers according to HARP Act, which is kind of

comical because they are the most qualified and knowledgeable people to do that role.”

MP-2: “The situation of not having medical physicists written into the HARP Act and the

regulations is that, first of all, the quality of the x-ray images will suffer because you have no

expertise in the department when they come up with a problem to diagnose fully what happened.

And then, the hospital when they are in a financial crunch, they would just cut physicists because

they are not required by law.

The interviews with the medical physicists, radiologists and jurisdictional representatives revealed that

diverse opinions regarding the role of medical physicists at the institutional level. It can, however, be

concluded that medical physicists are more relevant in smaller, non-academic institutions where there is

generally less physics knowledge amongst the radiological staff. It is undeniable that radiologists from

academic centres who also work as researchers tend to have more physics knowledge, which diminishes

the need for a diagnostic medical physicist. While medical physicists should not be mandatory if their

contributions are thought to be limited by the existing radiological staff within a facility, medical

physicists are technically knowledgeable in radiological concepts and should be able to act as radiation

safety officers for Ontario facilities.

7.2.2.2 Radiologists

Dose optimization efforts often affect radiologists in the most significant manner since lower doses

typically result in lower image quality and noisier images. However, there is increasing awareness of the

risks associated with high radiation exposure to patients, which has resulted in a shift in the attitude of

radiologists. Radiologists are not increasingly aware of the need for a balance of image quality and

Page 149: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

128

radiation dose. In the interviews with the four radiologists, each of them stressed the need to simply use

sufficient dose to answer the clinical question. Two of their responses are documented:

RP-1: “So you are trying to optimize dose to the quality that we think is necessary to answer the

question. If the clinical question requires minimal dose, in CT, let’s say that there is a dose that is

a fraction of an x-ray dose, we can utilize that ultra-low dose CT. if the clinical question, and this

is my medical knowledge, requires higher image quality, I may have to invest more dose, which

brings me back to the point, I need to know the clinical question.”

RP-2: “I want to make sure that the protocol that we prescribe is correct for the clinical

indication that we were given. That’s the first thing. The second thing I want to make sure is the

image quality was up to the task.”

The interviewed radiologists all have a keen interest in dose optimization, so they also ensure that other

factors, such as patient age and attenuation, are taken into consideration during their own exams.

RP-3: “We have ‘standard protocols’ which are used for most studies – which have been tailored

for patient size (pediatric institution) to balance dose and image quality, but we also have some

additional protocols designed for particular clinical indications.”

RP-4: “You have to have different protocols for different clinical questions. It means that certain

clinical indications require much less image quality than other questions. Umm, so you have to

balance and inform…what we do is we want to find out what’s the question and we also think

about the age of the patient. There’s certain protocols which we use in younger patients, like less

than 40 years.”

Unfortunately, some of the interviewees have had negative experiences with radiologists who are resistant

to the idea of dose optimization due to the change in image quality. Radiologists are often reluctant to use

newer CT dose-saving technologies, such as iterative reconstructed images, because there is an

adjustment period as the image texture is different from images constructed using back-projection.

Representative from the UK: “I would say the radiologists have been the biggest complainers

about reducing dose because their main element is image quality.”

MP-1: “They (the radiologists) are used to looking at a filter-back projection image and that has

a certain texture to it. In some of these iterative reconstruction of the image, the image looks

more plastic-y as a texture. They are just not used to it, right? They have to train themselves to

accommodate this new look and feel.”

RP-4: “I have the feeling that the technologists as well as the radiologists, if they do not put a lot

of time into it, to understand everything, they are maybe overwhelmed with all these technologies.

And that results in the effect that they don’t use it most effectively.”

Each of the interviewed radiologists is practising in an academic centre and has a keen interest in driving

dose optimization, which may influence his or her opinion about the needs and priorities in CT scanning.

However, the interviewed radiologists describe an ideal patient safety culture that every institution and

jurisdiction should strive for.

Page 150: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

129

7.2.2.3 Radiation Technologists

There was less focus on the role and duties of radiation technologists, but the interviewees who did

comment on radiation technologists described varying levels of involvement in the dose optimization

projects at the institutional level. However, radiation technologists who are responsible for the operation

of CT scanners are integral in the radiation protection efforts in medical applications. Training and

education standards have been mandated for radiation technologists in many jurisdiction’s regulations or

guidance documents, including Ontario’s HARP Act and the IAEA Basic Safety Standards. The

positioning of the patient is crucial in obtaining images of diagnostic quality. Furthermore, the experience

of radiation technologists also help to determine when alternative protocols for a patient is required. The

importance of their duties is highlighted through inclusion of technologists in dose optimization projects

at both the institutional and jurisdictional levels.

RP-1: “It’s (dose optimization project) not alone focused on dose reduction. It’s also protocoling,

timing, contrast, and all. Technologists are involved in our biweekly dose committee.

Absolutely.”

RP-3:”Creating robust protocols for patients of all ages and sizes, for various different

clinical indications is not a simple process. It is time consuming and involves a

considerable effort from technologists and leading radiologists.”

Representative of the UK: “So, in 2004, our professional body now called IPEM—Institute of

Physics and Engineering in Medicine—published a report with another working party, called

report No. 88 called Guidance on DRLs. […] And that was a working party now with everybody,

so it was IPEM—the physics people, NRPB—the people here, British Institute of Radiology—

which is a joint professional (body), so that’s radiologists, physicists and radiographers in it, the

Royal College of Radiologists, so it had a representative from the radiologists, and then the

College of Radiographers so it had representative from the radiographers.”

Although technologists are actively involved in dose optimization projects, they have a very well-defined

role. The well-defined role of each member of the radiology team helps to establish accountability at the

institution. The role definition also helps to maintain standardization of clinical workflows, which has

been shown to increase patient safety [147].

RP-4: “No, they (the technologists) are not allowed to change (the parameters) without getting

the okay from the physician. So, we have a very standardized protocol and I think that’s very

good because I know other institutions, they don’t have standardized protocols. They have

protocols by, for example, going by the radiologist so different radiologists have different

protocols, which makes a big mess and also confuses the technicians.”

7.2.2.4 Co-operation of the Radiology Team

The most commonly expressed sentiment amongst the interviewees is the need for co-operation between

CT stakeholders within a facility. Each member of the radiology team holds a unique perspective that

should be addressed in the design of dose optimization projects and/or regulations.

Page 151: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

130

Representative from Switzerland: “The most common problem in my experience is different

groups (radiologists, physicists, technologists) are not working together. Then we are faced with

a major problem. Problems like accidents happen in our country.”

Representative from Germany: “A very important thing is certainly to involve the people and to

make it clear, to co-operate with them, to communicate with them, to all the users why radiation

protection is so important.”

Representative from Australia: “I think one thing you need to do is to make sure all the various

players, all the various groups are informed and on your side.”

7.2.3 Clinical Justification

Clinical justification is a very important concept in CT diagnostics. As briefly discussed in 7.1.1.3, the CT

imaging workflow begins with the referrals from family practitioners and so, appropriate referrals

according to clinical indication can reduce unnecessary patient exposures. Increasing awareness for

clinically justified referrals was discussed, as the major referral guidelines that are used by the selected

jurisdictions were identified.

Representative from Ireland: “We just recently adopted national referral guidelines. We have

adopted iRefer, a guideline from the Royal College of Radiologists in the UK. Yeah, so up until

last year, Ireland didn’t have any of their own criteria for justification or referral guidelines, so

because the UK versions were quite so good, and they mainly agree to adopt those as our own

national guidelines.”

Representative from Switzerland: "What we do actually is in the moment, we don’t have the

future planning (now it’s finished), but in the moment, each institution has to define what

guideline they say are strictly used. The French, British, American or even Australian one, but

these four are the main ones. But we don’t say you have to use this one, but we say you have to

use one. You cannot just do nothing.”

Furthermore, the best practices to approval of referred exams by radiologists. Clinically unjustified

exams should ideally be turned into learning opportunities for the referring physicians. Admittedly, some

referring physicians are resistant to the explanations provided by the radiologists, but the majority of

referring physicians are interested in recommending patients for the correct diagnostic exam.

RP-4: “The referring physician wants to have a CT scan, then they submit either online or on the

written form, they submit an audit sheet. And then, the radiologist is protocoling the study and

before or while we are protocoling the study, we always read the clinical indication and we also

look at the prior history of what the patient has had, what’s the history, how many scans they had

and we decide first, is there an indication for a medical study, and the second thing is, ‘is CT the

best medical…is it the best diagnostic test for the patient?’”

RP-1: “I think most of the time here, I would say, clinical referrals are very reasonable. And if

you call them up and you explain to them, “you know what, I have a better idea, can you use it?”

there are some primary users, some stubborn idiots, out there but the vast majority is very

cooperative, very understanding, and if you tell them, ‘leave that with me, and I give you the best

result,’ they actually say yes.”

Page 152: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

131

Although the best practice would be to inform the referring physician of the inappropriate scan, one of the

radiologists provided a more realistic description of the possible perspective of radiologists in Ontario. In

Ontario’s fees-for service model healthcare system, radiologists are paid in relation to the number of

procedures performed. Any unrelated work, including the best practice of communicating with referring

physicians about clinically unjustified scans, results in loss of income. Furthermore, the interviewed

radiologist re-iterates the possibility of resistance from the referring physician.

RP-3: “Currently there is no incentive to a radiologist spending 40 minutes tracking down a

referring physician, discussing the history, cancelling the test or providing alternative imaging

that does not involve radiation, organizing this logistically, and ideally talking with the patient. It

is not practical in a busy radiology practice and involves loss of income and risks to professional

relationships.”

From the thematic analysis of the qualitative data, it is undeniable that the optimistic perspective for best

practices in managing clinical justification concerns is through the active use of clinical referral

guidelines and communication with the referring physicians. However, the drawbacks to this workflow in

Ontario are the potential loss of income and risks to professional relationships. If diagnostic

appropriateness is to be improved, greater incentive for radiologists to contact referring physicians and a

jurisdiction-wide approach with engagement from both the referring physicians and the CT stakeholders,

such as the development of an easy to use computerized referral tool, are required.

7.2.4 Compliance Monitoring

Dose optimization approaches within jurisdictions require compliance monitoring to measure the clinical

uptake of legal standards, and to identify problems that may have arisen. Accreditation, inspections and

clinical audits are inter-changeable terms used in the context of compliance monitoring by different

jurisdictions. Each of these compliance monitoring procedures involve review of technical standards for

CT scanners and clinical workflows. The differing aspects of compliance monitoring between different

jurisdictions are the frequency of review, method of review (i.e. on-site or remote), and the content of the

review, which are dependent upon the available resources within the jurisdiction.

7.2.4.1 Frequency of Review

The frequency of compliance monitoring varies between jurisdictions. Many of the jurisdiction have

specified accreditation cycles for each modality type, which are transparently stated in the legal standards

or supplemental documents. For example, the Texan legislation indicates the inspection frequency for CT

facilities to be every 2 years [159]. However, Switzerland takes a notably different approach to

compliance monitoring schedules.

Page 153: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

132

Representative from Switzerland: “Schedule? They are schedule free. […] So, we focus each year

on a part. For example, there is a campaign right now looking at all mammography. When we

finish this, we publish a national report about mammography situation. We do this for CT, radio-

oncology. Besides these campaigns, we look at all new CTs and replacement of CTs. But it’s not

so regularly like every year. No.”

The non-scheduled approach is, perhaps, a more realistic representation of the CT radiology department

and the associated clinical workflows. Before a scheduled inspection, the CT facility is likely to make

adjustments and present what the inspectors are looking for. One of the medical physicists described the

problems associated with scheduled inspections with an analogy:

MP-2: “I think we should move away from a model where you send x-ray inspectors that are like

policemen. In a way, it is just like speeding right? You can speed however way you want unless

you are caught by police. Everyone knows that the chances that you get caught by the police is

few and far between even though you may be speeding all day long, right? Unless a policeman is

there, you can get away with murder.”

7.2.4.2 Method of Review

Compliance monitoring can be performed using two methods: on-site or remote.

On-site

On-site inspections of radiological facilities are performed by qualified inspectors within each

jurisdiction. These inspections can be performed by the supervisory committee or by an appointed

organization. Each inspector is provided with specific checklists of the requirements to obtain

accreditation renewal. Some methods of inspection are described:

Representative from the UK: “You have got the CQC, which is the Care Quality Commission.

And they are responsible for inspections in England. […] CQC covers all types of aspects of

quality in healthcare. […] So, they will go to the radiology department and they will generally

spend a day there, they will ask for their clinical procedures because IR(ME)R talks a lot about

having procedures and good documentation. Part of IRMER was the requirement to note down

the doses that were relevant for each patient. So, either the actual dose or all the different

parameters that enable you to calculate the dose. So, in CT, you could in theory put down the

tube current, the kV and all the offered underlying information, or you could just put the

computed tomography dose index, which isn’t actually a patient dose.”

Representative from BC: “We go into a facility once every 4 years at a minimum and it’s an

announced visit so they know we are coming. We come in and we do an assessment, which

usually takes 1-2 days. We assess all of our standards. […] we have requirements, which I am

sure you have seen, in term of developing diagnostic reference levels for the facilities and

optimization dose as a result for that. Obviously, they have to record dose for CT and keep it as

an Appendix for each patient that comes in.”

Representative from Switzerland: “We are looking at processes that are in place and not just

measuring doses, but looking at the whole safety culture. […] what is safety culture evaluation?

Well, you see, we can ask them if they can show us how they deal with incidents, if they have

internal directives, who is in charge for that, is this person known by the staff, is there a regular

update of safety information and so on. […] It focuses on processes and not just sitting in front of

the terminal and looking at the pictures.”

Page 154: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

133

Remote Monitoring

Remote monitoring requires the submission of required documentation to the supervisory committee.

Alternatively, remote monitoring can occur in the mandatory documentation of processes. Although the

records are not submitted at a specified frequency, the supervisory can request these documents randomly.

The possibility of random checks encourages continuous compliance with the legal standards. Germany is

currently rigorous in its remote monitoring:

Representative from Germany: “They, the employees of the authorities, they regularly—regularly

means around every three years---they regularly ask the users of the different x-ray devices to

send them a sample of exposure data, images, but also the results of the constancy or acceptance

test of each device.”

Interviewees from Ontario are in support of remote monitoring standards. Remote monitoring measures,

in the form of document submission or random checks, are both less resource intensive. Furthermore, it is

more representative of the daily workflows in the radiological facility.

RP-1: “I am worried when government start to audit and come in because we pay so much. This

auditor is paid, and he/she probably has a secretary, and probably has an office, and probably

has multiple auditors. […]So, you can blow up the administration. The other possibility is you

just submit it to the government. You just submit a document. […]Hospitals submit once a year

the document that shows (compliance). And if you lie, then there has to be consequences. But I

think by just having the process alone, you probably achieve 90% of your goal (of dose

management regulations).”

MP-2: “The facilities would take all types of tests that include the dose to the patient, the image

quality etc. And then, they will file a report to the organization and then, the organization will

spend time evaluating those reports and see whether you pass or you better be certain that

problems are fixed. […] accreditation of x-ray facilities would be a much better one, rather than

this kind of traffic cop kind of scenario where you will be okay to do whatever you want until an

x-ray inspector comes.”

Combination of Methods

Another possible approach is a continuous assessment during the accreditation cycle. This approach

combines the on-site inspections with self-audits and other related activities that are required to be

documented. Assessment of the required documentations from the 4 year period occur during the on-site

visit, which encourages facilities to continuously comply with the standards. Some of the jurisdictions,

including BC and Germany, have taken this approach because it allows for less frequent on-site

inspections. The mixed combination approach of BC requires on-site inspections once every 4 years

[160], whereas Texas’ accreditation renewal system only requires an on-site inspection every 2 years

[159]. The difference between BC’s DAP accreditation program and Texas’ inspections program is that

BC’s program involves continuous assessment activities during a 4 year cycle, which includes quality

Page 155: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

134

control testing, self-audits and proficiency testing of staff when an on-site inspection is not scheduled

[160]. Due to the costs required for on-site inspections as described by RP-1 previously, a combination of

compliance monitoring methods may be suitable for jurisdictions with less healthcare spending.

7.2.4.3 Content of Review

Every jurisdiction has a different set of requirements for CT facilities that must be fulfilled to pass

compliance monitoring. However, the interviewees were in agreement that there is a need to assess

clinical workflows and operational procedures if dose optimization is to be achieved consistently across

facilities. A commonly recommended process for conducting clinical audits it the establishment of a peer

review program. The general idea is to have radiologists from different facilities review the same image

to assure consistency in diagnosis. Furthermore, peer review requirements allow facilities to observe the

varying techniques and protocols for similar indications, which provides mutual learning opportunities for

the radiology staff. Two of the recommendations for peer review processes are described:

MP-1: “What you might find interesting is that British Columbia as part of our diagnostic

accreditation program has started a peer-review process. […] (What) I’m hoping is going to

happen is that in the peer review process, they don’t only comment on (the diagnosis). I don’t

even know if they see the diagnosis of the other radiologists, they might not. But they can make

other comments (that) say, ‘you know, this image is not diagnostic.’ So, I think that’s going to

help level the playing field.”

RP-4: “If you don’t read CT from another institution that may be running doses lower than you,

how would you ever know that you could go lower? Because nobody wants to miss anything, and

nobody wants to be the first to go really low. So, that kind of information sharing —image

sharing—would be useful.”

Representative from Switzerland: “The whole patient cycle from the patient coming in, and

indication, and is it justified to do this process so all these things should be looked at in the future

by a peer review system. It is very complicated, but it’s the only way we have to go forward.

Europe and other countries are trying to do systems like these. […] The peer review system will

be done by radiologists and biomedical physicists and technologists. Actually, you are getting

peer reviewed by colleagues in other cities.”

Peer review processes across a jurisdiction are ideal, but two radiologists expressed support for the

requirement of annual protocol reviews within a facility. However, the justification by each radiologist for

facility-based protocol reviews differed. One radiologists explained that local protocol and dose reviews

can reduce dose gradually by adjusting protocol parameters at the peer review discussions. The other

radiologist’s concern was simply to ensure that the standardized protocols are being utilized accordingly

by the technologists.

RP-1: “I think I would love to see a requirement of every institution to have a documented,

auditable process in which CT protocol and doses are critically discussed and reviewed. […]

Let’s say a formalized document that each department that runs a CT has to you know, hold and

Page 156: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

135

does an annual roundtable discussion in which protocols will be reviewed, and there should be

some sort of feedback on dose.”

RP-3: “Institutional and CT machine specific protocols for each type of CT examination are an

essential part of radiation protection. This is challenging for departments which may have many

different CT scanners in use but important in radiation protection, especially where a large

number of technologists may rotate through CT or perform scans on call at nighttime, when

regular staff are not around. Audits of adherence to protocols should be performed.”

RP-1 provided a possible approach to use a data-driven approach to adjusting protocols that can increase

acceptance from radiologists.

RP-1: “I would leave that open because you don’t want to endorse any company. There is

different things one can do. On a dose monitoring software system or there could be a sample or

a sub-sample on a random basis. […] Or you could argue that maybe 1% of the studies should be

documented. So, (these methods allow you to) look at trends.”

7.2.4.4 Required Resources

Both financial and human resources are required to perform compliance monitoring within the

jurisdictions. All of the interviewees were unsure about the financial resources required to conduct

compliance monitoring. However, the representative did acknowledge cost as the biggest barrier for the

DAP program.

Representative from BC: “Well, the biggest barrier is cost. […] Because we need to bill for our

services, and with the financial climate right now in healthcare, there’s not a lot of extra money

laying around for these kinds of programs so the feedback we tend to get from our clients is the

costs associated with our program and what are we getting for the cost. And obviously, it’s a

tough time right now to squeeze more money out of people.”

The interviewees also agreed that radiation protection in medical applications is a specialized field, which

limits the participation in compliance monitoring to qualified individuals who have a working knowledge

of medical physics and ionizing radiation equipment. Two of the jurisdictions explained the human

resources that are required to maintain their respective inspection programs:

Representative from the UK: “There is some people here (at Public Health England) who

supports Scotland or Wales in their inspections. […] In Scotland and Wales, they don’t have

medical specialists in medical physics or radiography background staff to do the radiology

IR(ME)R inspections. […] We (At Public Health England) have a contract with Scotland and

Wales and Northern Ireland to supply somebody to help them through the process. But as I said,

in England in the CQC, because it’s run by a physicist—a medical physicist—and they have got

another physicist and a radiographer on their team, so they can do the IR(ME)R inspections

without having outside help.”

Representative from Texas: “The inspectors tend to be within state, and so, we have lost count. I

think we have about 26 inspectors for x-ray alone in the State, in addition to our mammography

and our radioactive materials inspectors.”

Page 157: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

136

7.2.5 Role of Technology in Dose Optimization

Ideally, replacement of CT scanners are useful in ensuring the availability of the latest dose-saving

technologies and software upgrades, which helps with the application of new techniques and dose-saving

protocols. Some of the advantages of newer technologies are explained:

RP-1: “I am expressing my opinion. 8 years is the absolute maximum. After 8 years, you have a

fundamental change in technology. […] There is a five to ten year time delay between technology

arriving and until it’s being implemented in practice.”

RP-2: “Now, if you compare them to a scanner we can get new right now, the new scanners do

have iterative reconstruction (IR) which the older scanners do not have. Our standard protocols

are already a lot lower than other people’s. In some cases, it may be lower than other people

using IR. Having said that, we could actually lower the radiation dose even further if we could do

this but the software does not go on the old models so you would have to replace the CT.”

Representative from Portugal: “Sometimes, there are simple software upgrades that they can do

it, and of course, you need to pay. But after a few years, software upgrades cannot be applied to

your scanners. It is easier to get you to buy a new one if you can no longer upgrade.

The limitation of older CT scanners inspired discussion regarding the replacement cycle of CT scanners

in each jurisdiction. The frequency of replacement ranged from 7 years to 15 years. The contrast in

replacement frequency was attributed to the available resources, and the institution type (i.e. public vs.

private).

Representative from Germany: “I think in Germany, the CT scanners will be replaced 7 years,

around 7-8 years. […] We have still hospitals that work with ones that are past detector’s life.

These machines are still there. They are still available, but there are only a few of these scanners.

[…] For most university hospitals, I have the feeling they replace their scanners every 7-8 years.

Representative from Portugal: “In the last years, we changed less because of the crisis. I don’t

have that data because we do not have studies about that. But before the crisis, we changed a lot

of technologies especially in private institutions, the most known private clinics changed every

few years, and they are more involved with the manufacturers. They have more fast responses

from the manufacturers. Public institutions take more time, take about 10 years, more or less.”

The benefits of frequent replacement of CT technology are evident, but jurisdictions cannot legally

request functional CT scanners that meet the technical requirements to be replaced. However, some of the

jurisdictions have developed procedures to convince facilities to upgrade their scanners. Switzerland

explains its approach:

Representative from Switzerland: “What we are looking at is the most ways we can make

recommendations. Because the radiologists or the technologists are very keen to change their old

machines to a new one, but they have to get the money from the hospital. Sometimes when it is a

really old machine, and we think that it is really outdated, we just make recommendations to the

hospital. We talk to the director and say, it is now urgent that you change this machine. That

helps.”

Page 158: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

137

7.2.6 Continuing Professional Development

All of the jurisdictions interviewed described training programs and continuing professional development

opportunities for CT stakeholder. Some jurisdictions offer larger scale development programs, while other

programs are customized to the needs of individual facilities. However, the end goal is common to all

these programs, which is to encourage knowledge sharing amongst radiological staff.

7.2.6.1 Large Conferences or Education Summits

The challenges faced by CT stakeholders, such as radiologists and technologists, vary depending on the

environment and work culture of the institution. For example, it has been hypothesized by one radiologist

that community centres face unique challenges different than those found in academic centres.

Furthermore, the representative from Switzerland explained that compliance struggles are more prevalent

in rural facilities.

RP-1: “But it shouldn’t be arrogant in the sense that I blame them (i.e. community institutions)

for a dose problem. It’s not at all. It’s just the awareness and possibly also access to latest

technology may be different than academic centres. Because we see so much, and we have access

to better equipment. […] Equipment also means training […] controlled documentation,

controlled service, access to sales representatives or applications specialist from the companies

who set up the right protocols. Those things may be different in the periphery. […] I am not

blaming anyone in the community hospital because I must tell you they face different challenges.”

Representative from Switzerland: “Most problems are very small. Radiological institutes that are

not in the cities and are in the countryside may need more help.”

Jurisdiction-wide educational conferences are, therefore, often held by professional colleges to ensure up-

to-date knowledge of its members. A radiologist described one such conference:

RP-2: “I mean there are a lot of conference. University of Toronto does (and) I think they have

for many years organized a huge conference where 300-400 community radiologists come. […]

they attend lecturers and discussions on every part of the body. Basically, it is for imaging,

including CT, and now also includes radiation dose in the chest, especially something like

radiation dose.”

More importantly, however, may be inter-professional conference or educational summits because dose

optimization requires co-operation from all CT stakeholders. Many jurisdictions have recognized the

importance of having dialogue between all the important actors in dose management efforts, including

radiologists, medical physicists and technologists. The importance of co-operative professional

relationships is reflected in the multi-discipline conferences that occur. Two of these inter-professional

educational activities are described:

Representative from Switzerland: “We (as the authoritative body) meet with the radiologists

twice a year. I mean the radiologists and the president of the Suisse Society of Radiologists and

his colleagues from the committee. […] So, we can form a close collaboration between them.

Then, we also have not every year, but every two years, national radiation protection day where

Page 159: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

138

we talk with a particular audience of medical staff about patient safety and so on. So, we are

involved a little bit. This is very important.”

Representative from Australia: “Every 4 years, we have in Australia what’s called the Combined

Scientific Meeting of Radiologists, Radiographers and Medical Physicists. And in the many years

between that, they have their own little conferences. But every 4 years, so last year (in) October,

we had a combined meeting.”

7.2.6.2 Facility Specific Training

While large educational conferences are ideal for dialogue between the various CT stakeholders or

radiologists from different backgrounds, the lecture and seminar style of these conferences do not provide

the necessary training that can be applied and adapted to the unique workflow of each facility.

Customized training at the specific CT scanners was supported by the interviewees who explained the

importance of hands-on training.

Representative from Germany: “Education, training, is (a) very important aspect that should be

improved. In particular, the training at the machine.”

RP-4: “But at the time of installation, you always get the training but that is not enough at all—

this training at the beginning. That’s just a basic training you need. And then, you can also talk

with the representatives of the CT manufacturer on a different level after you use the

technologies.”

Besides training from manufacturers, academic research centres can also actively participate in

customized knowledge sharing with smaller, rural institutions. Teams of knowledgeable and experienced

researchers or radiologists should visit each CT facility when providing training because it allows for

better understanding of the facility’s unique workflows and challenges. Dose optimization projects and

protocols can be directly adapted to the needs each facility, in the presence of the knowledge sharing

team. Two of the successful initiatives that were undertaken are described:

RP-4: “I would prefer that well-trained or specialists from academic centres actually go out to

(the community centres). […] You have to be really at the CT scanner to get trained, to get

advice, how to do it. […] We did training of 10 hospitals like 4 years ago, we went to smaller

community hospitals from an academic centre with a team of 2 persons. There was a technician

and a radiologist, and we trained them. We advised them and we had really good results.”

Representative from IAEA/ICRP: “We train them (i.e. CT stakeholders in developing countries).

There’s a lot of mentoring required. […] (We had) to explain to them, to ask them to prepare the

data according to the framework we had, and then I bought them to some centres for the training

once they had done initial phase 1. […] It was not the standard training on radiation protection

and radiology. I used to bring them on specific training on patient dose assessment and patient

dose management.”

Page 160: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

139

7.2.7 Results of Non-Compliance

The approaches to oversight and ensuring compliance that have been undertaken by the jurisdictions in

this study contrast starkly. Due to the legally binding nature of the CT standards in the jurisdictions, the

first option for oversight is punitive sanctions, such as monetary fines and suspension of licenses. The

alternative approach is to simulate “soft law”, or non-legislative modes of policymaking, which is

increasingly common in healthcare policies [161]. The basis of “soft law” is the voluntary agreement

between the supervisory body and the targeted users to comply with best practices [161]. In CT radiation

protection, “soft law” translates into support and recommendations being provided to individual facilities

that are non-compliant. Many of the European jurisdictions have decided to use a combination approach,

where support is provided before legal actions are taken.

Representative from Germany: “If they find a drawback, they— the people from the medical

authorities—try to explain how to improve. They will teach how to improve the protocols, the

techniques. They try to explain how, for instance, the automatic dose modulations work and how

to use it. And the offices of the states are informed if the improvements cannot be identified after

some months. […] The office of the states can penalize the users.”

Representative from Switzerland: “Well, first of all, when we make an audit or inspection, we

introduce changes as a recommendation actually. We send it to them and discuss it with the

hospital and if they agree (and) if we have the signature of the radiation protection officer, that

normally is not a problem. […]But if we think that it is really important that they have to do it

even if they don’t want to in the beginning, then we have to write it directly in the license. So they

get a new license with these charges. And we suggest they don’t do this. Then, if they do not

follow through, we can withdraw the license. […]Another possibility is to fine them. We have this

possibility, but the possibility is low because if you fine someone, it must be so jurisdiction

clear.”

Representative from Ireland: “At the moment, the way legislation is enforced and this isn’t just in

Ireland but across Europe, it kind of seems that there shouldn’t be fines, and the stick approach

shouldn’t be used if possible. And that (it) is better to use an education approach and to point out

differences and to encourage people to optimize as opposed to fine them directly because some of

them may have good reasons.”

This contrasts starkly with the more rigid non-compliance consequences of North American jurisdictions,

which do not offer direct support for corrective actions. Non-compliant facilities are simply provided with

a timeline to take corrective action and a recommendation to seek help from qualified professionals.

There is no opportunity for the supervisory authority and the facility to develop customized solutions for

each facility.

Representative from BC: “If any of the standards are not in place or they are not meeting our

standards, we issue a report within two months’ time, and that report will have all their

deficiencies listed in it. And depending on the risk associated with those deficiencies, they have

timelines for implementation. So if it’s something we deem to be extremely high risk, they need to

Page 161: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

140

put it in place immediately, which is within a couple weeks. Some of the very low risk things, we

have timelines up to 12 months.”

Representative from Texas: “And then we have the PSQA (i.e. Policy/standards and quality

assurance), which is what we call our reviewers and they take our inspection reports, review

those for accuracy and any errors and then, they follow up with the registrants directly if there’s

any violations issued during an inspection. […] So, it’s terms and conditions they would have to

fix. We walk a fine line in that we are not allowed to provide any consultations.”

Interestingly, the interviewees are in agreement that acceptance from all CT stakeholders as the key

element for success in implementation of CT dose management regulations, despite the non-cooperative

approach undertaken by North American jurisdictions in the oversight of the CT facilities. Co-operative

relationships and dialogue between the supervisory authority and the CT stakeholders are important in the

clinical uptake of new CT standards. Furthermore, the representative from Switzerland explained the

psychological advantages to communicating with the stakeholders before the implementation of new

standards.

Representative from Texas: “I always like the fact that we tried to stop and ask ourselves what

does this rule change mean for the registrants—did it impact them, is it something they can

actually obtain and is it something that is going to truly benefit either the individual taking the x-

ray or the person giving the x-ray because that’s ultimately who we are supposed to be

responsible for. And try to make sure that we didn’t give them something that was so overly

burdensome that they can’t go back to doing their real job, which is truly patient care.”

Representative from Switzerland: “Before you make an ordinance or a regulation, try to get all

these people in a new stakeholder involvement process. Because if you make a law or an

ordinance before they are involved, they get upset. Then you need 2-5 years to calm them down.

But if you tell them, and they know that it is coming up, it is totally different psychologically even

if they don’t like it.”

Representative from the UK: “I think get the professional bodies involved because you are

looking at good will, but you are looking at professional standards as well. […] There’s a whole

legislative part but there’s also professional standards part. So, I do think that’s important.”

7.3 Ontario Model for CT Dose Management Regulations

The key considerations in the design of dose management regulations were elicited from the thematic

analysis of the qualitative interviews. The concerns of practising radiologists and medical physicists in

Ontario were prioritized because they will be most affected by changes in Ontario’s CT standards. The

recommended framework for Ontario’s CT dose management regulations is divided into two sections.

Firstly, important minimum requirements were defined for inclusion in the regulations. Secondly,

additional approaches that are expected to strengthen dose optimization were described for possible

implementation into the regulatory structure.

Page 162: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

141

7.3.1 Considerations for Regulations

The recurring concerns from the interviews with radiologists and medical physicists were highlighted

through thematic analysis. The expressed opinions and described experiences that align with these

concerns from jurisdictional representatives were also considered.

7.3.1.1 Resources

Any dose optimization approach adopted by Ontario will require both financial and human resources.

Insight regarding the requirements to maintain an accreditation or on-site inspection program is provided

in Section 7.3.4.4. Furthermore, the representative from Switzerland described the financial burden for the

review and update of DRLs.

Representative from Switzerland: “It is difficult to say. With the Institute of Radiographique in

L’Essen, we have a contract for 5 years just a medical part, I would say about 100,000 Suisse

Francs. Just about 100, 000 dollars per year. Just 2-3 people paid there to work for us. It is a

very close collaboration with them. It is very important that they have a good understanding of

what we need. Because if we just give something to a University, they look at it from a scientific

point of view and this is maybe not what an authority needs.”

Radiologists from Ontario echoed their concerns regarding the financial resources for potential dose

management regulations.

RP-1: “The only roadblock I could see is, let’s assume you have a private practice and they have

none of which (of the required resources). They have no physicists, they have no protocol

manager, (and) they have nothing. It’s just for them to transition to that scenario may be a cost

factor. Maybe once you have to do it, you should have collaboration or an association with an

academic centre.”

RP-3: “The greatest concern is that introducing a regulatory process that does not currently exist

has significant manpower and financial implications. […] Funding for this needs to be available.

If it is not, and the reality turns out to be that there is no enforcement of new regulations, then the

effort will fail.”

The design of the CT dose management regulations shall, therefore, account for the financial resources

required to sustain the program. Feasibility studies are recommended before the implementation of any

dose optimization approach, such as accreditation, or DRLs, are implemented.

7.3.1.2 Acceptance from CT Stakeholders

Achieving acceptance from CT stakeholders is an essential element to successful implementation of CT

dose management regulations, as briefly described in Section 7.3.7. Practising radiologists in Ontario

were concerned that innovation will be suppressed and practice decisions will be controlled, with the

introduction of legislation in clinical CT practices. Moreover, the implication of regulations raises

questions regarding the governance of radiology professionals.

Page 163: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

142

RP-1: “I think, as soon as legislation comes into medicine, it can only go wrong. […] I think in

Germany, it (i.e. the CT standards) has gone too far. It’s very rigorous and it has actually

prevented a lot of research, and a lot of progress because it’s too rigorous.”

RP-2: “I would think the government are probably the wrong people to do it. It should be an

initiative coming out of the OAR.”

RP-3: “Who will lead the design of the regulations? Who will subsequently run the inspectorate

day to day? Where will it be based? Who will be the inspectors?”

The medical physicist practising in Ontario weighed in on the effect of regulations on radiologists.

MP-2: “Because you cannot mandate (dose optimization). Everyone has to remember that the

physician-patient relationship is static. That means you can’t change that. But the physician can

give as much dose as they are required in order to make the best possible diagnosis. You can’t

barge in with a regulation. You can only suggest.”

Each radiologist offered their perspective on how best to involve all CT stakeholders in the policymaking

process for potential new CT dose management regulations. In addition to the idea for remote monitoring,

RP-1 also recommended the implementation of DRLs.

RP-1: “Diagnostic reference levels is probably a reasonable thing to do. You don’t need to start

from scratch because I can argue with you the technology is the same. And I would ask, ‘why

would you suddenly need a different dose level than in Europe when you use the same

technology?’ They would only argue, ‘my patients are bigger. Yes, we know that but if you have

dose modulation, you shouldn’t be (different).’ So, you can’t have many excuses of why you

would deviate from it. I wouldn’t start from scratch.”

While RP-1 provided specific procedures for efficient compliance monitoring and establishment of DRLs,

the other two Ontario-based radiologists provided more generalized descriptions of the ideal process to

design CT dose management regulations.

RP-2: “I think the first thing that needs to happen is to engage the radiology community. And

also, the radiation dose experts—be it, biomedical engineering or physics or whatever. And the

idea would be to establish Ontario reference levels for procedures. If we could do that and

actually have the work come out of that working group, I think it would make a lot more impact

than an arms-length body trying to do something unilaterally. I don’t think anybody would be

against some guidelines and some thresholds, but I think people don’t have a lot of engagement if

they don’t feel that it is relevant to what they are doing. And that they haven’t been taken into

account.”

RP-3: “Care needs to be taken that any regulations are crafted to be sufficiently adaptable and

principle–based to cope with the inevitable advances in technology that are occurring, variability

in the equipment available at different centres, and some variability in imaging requirements (e.g.

very complex surgery in a tertiary care center may genuinely need a higher dose CT study than a

standard broad use study that might be performed in a local hospital). Too precise numerical

dose regulations would be inappropriate and result in much frustration. However, it should be

possible to craft regulations based on ensuring that the principles of radiation protection are

being actively pursued at each imaging institution.”

Page 164: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

143

Similar sentiment for involvement of CT stakeholders is expressed by the jurisdictional representative

who have had experience in implementing CT regulations. The design of Ontario’s CT regulations

should, therefore, be performed by a multi-discipline taskforce of CT stakeholders including members

from the potential supervisory authority, radiologists, medical physicists, radiation technologists and

medical engineer. Furthermore, the legislation should be written with flexibility to accommodate potential

changes in CT technology and associated clinical workflows.

7.3.1.3 Incentives

Success of CT regulation implementation is largely dependent on the engagement of the CT stakeholders,

which is substantially increased when there are rewards for good practice. Interest in dose optimization,

however, is more pre-dominant from CT facilities that have a commercial interest.

Representative from Switzerland: “A major change happened in the last 10-15 years when we

started with the DRL business. There were a lot of institutions being stubborn who didn’t

understand why they had to do it. Now, from all the discussions in the public and newspaper

about what’s happening, they discovered that you can propagate that doses are very low, (that

you have) new machines, and a very high culture of radiation safety. This changed a lot, in both

big hospitals and private hospitals.”

Representative from Portugal: “If you have my article, you can see that I only have a few private

institutions that responded to my survey. I have been told that the public ones were more worried,

and the private ones have some commercial interest and they do not give the information. […]In

the last 2 years, there were more private institutions that are getting more worried. I think they

are more worried because if you go to a private institution or clinic, and you say that your exam

is performed with lower dose, you could use it for your commercial interest. Maybe they are

trying to promote radiation for commercial interest, but this is not bad?”

Representative from Texas: “They all hang or it’s required that they hang their ACR certificates

in their suites for CT or whatever department they are in. I have seen some information that has

been pushed out in articles or on advertisements or on their internet sites that say we are

accredited with this or we have reached this goal or something like that. I think that they do take

that as a talking point or bragging point for their facility.”

One radiologist echoed the need for incentives in the Ontario CT regulations for high levels of

engagement from the CT facilities. However, the public healthcare system hinders the potential

opportunities to further the commercial interests of the facilities.

RP-3: “As we are a largely state-funded health system in Canada, is there a way the government

can actively encourage centres providing the best radiation dose management and safety? For

example, reward financially those hospitals in achieving the most to counteract the inevitable loss

of income that unfortunately tends to be associated with greater radiation protection efforts. A

combination of ‘stick and carrot’ is often most effective in driving change – both increased

regulation and reward for good practice in this case.”

Page 165: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

144

An incentives-based system is evidently useful in obtaining engagement from all radiological facilities in

Ontario. Under Ontario’s fee-for-service system, it may be beneficial to have public dose trends for

review by potential patients. This may encourage dose optimization by CT facilities as patients who

access the dose level comparisons are more likely to request diagnostic referrals to facilities with lower

dose distributions for similar scan types. Data collection and analysis methodology should be uniform and

the patient size inclusion for the dose distributions should be documented to maximize the comparability

of the data. A feasibility analysis of this recommended procedure should be performed. Furthermore,

alternative methods to implement incentives in a public healthcare system should be investigated.

7.3.1.4 Adaptability

Due to the different workflows and challenges between academic and community centres, the CT

regulations should be written with high adaptability. The results of unachievable standards were explained

by representatives from Portugal and Ireland, whose dose optimization efforts were significantly behind

other Euratom member states as explained in Section 4.4.2. Furthermore, one radiologist expressed

concern for the loose definition of “as low as reasonably achievable” doses. Guidance is required to adjust

the dose levels in accordance with available technical expertise and CT technology.

RP-2: “There has got to be some skin in the game. For example, there is a process you could

actually undertake, which is to say we want to achieve as low a dose as possible and that’s all in

the legislation and we all embrace that. But then, do you say as low a dose as possible for this

platform of CT? Because if you say, what’s the current standard, what’s the state of the art

machine and what can it do, that may be 30% lower than what’s already installed. When you get

that threshold, do you say this is only relevant for fourth generation CT and that’s it? The

thresholds for third generation, these ones for second generation.”

7.3.2 CT Radiation Protection Publications Design

Ontario’s design for CT dose management regulations should consist of two publication types. The first

required document type is legislative. The new CT standards can, therefore, be added into the existing

HARP Act or developed into a new legislation. The legislation should specify the new standards for

compliance of CT facilities, without providing in-depth information. The lack of details ensures that the

legislation can be interpreted as new technologies and clinical workflows evolve [98]. The second type of

document should be supplemental to the main legislation and provide the missing details and procedures

in the legislation. The HARP Regulations currently act as subsidiary legislation to provide additional

explanations of the HARP Act clauses. However, the alteration of the HARP Regulations to include the

details of the new CT standards are not recommended because the legislative powers of HARP

Regulations would require substantial time and efforts before changes actually into force. It is

recommended that an additional supplemental document, such as a safety guide, be formulated to expand

Page 166: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

145

on the CT standards in the legislation. Each publication type should be written in accordance with the key

domains identified in Section 6.3.1.2 to ensure high effectiveness and implementability.

7.3.2.1 Minimum Theme Requirements

The minimum requirements that must be included in strong CT dose management regulations for Ontario

were formulated in accordance with the results from the comparative analysis of radiation protection

publications in Chapter 6. The minimum theme requirements, as summarized in Table 23, can be divided

into two categories: general requirements and dose-optimization related requirements. The standards

should be briefly recorded in the legislation, while detailed procedures should be provided in the

supplemental document to help intended users achieve compliance.

Table 23: A summary of the minimum requirements that should be included in Ontario's CT dose management regulations. The

themes and sub-themes that were identified as mandatory in radiation protection for medical exposures publications in the RACT

2 evaluations are discussed.

Category Theme Description/ Comments

General

requirements

General Provisions

1. The current HARP Act and Regulations resulted in a low score of 2

in the clarity of legislative scope domain.

2. The general provisions should detail the situations in which the

legislation applies and the goal for the legislation

3. The supplemental document should also contain general

provisions that explain the goal, targeted problem, targeted user,

practice setting and the rationale for development

4. General provisions form the basis of comprehension of the entire

document for the user, so all the sub-themes for this theme in

RACT 2 should be fulfilled

Responsible

Authorities

1. The authority that drafted the CT standards should be specified.

The taskforce that develops these standards should contain inter-

professional perspectives of various CT stakeholders.

2. A supervisory authority should be appointed to ensure

compliance with the standards

3. If applicable, external consultations should be utilized to increase

transparency

4. Details of this theme should be easily accessible in the legislation

to maximize transparency and accountability

Licensing

requirements

1. The application, modification, transfer, suspension or revoking of

licenses should be detailed

2. Clear criteria to obtain a license

3. Licensing in this sense refers to the permission to acquire a CT

scanner, which is analogous to the current HARP Standards

Technical 1. All the steps in a CT scanner’s life cycle should require detailed

Page 167: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

146

General

Requirements

Requirements quality control tests (i.e. new installations, maintenance, and

decommissioning)

2. Procedures to repair malfunctioning equipment should be

detailed

3. Recordkeeping requirements should also be included for

potential remote monitoring by the supervisory authority

Facility

Requirements

1. Shielding design requirements in HARP Regulations are currently

inapplicable to CT facilities1

2. Facility design requirements, such as designated areas, should be

explained

Emergency

situations and event

reporting

1. Internal incident reporting and investigation systems (i.e. for

unintentional radiation exposures)

2. Emergency situation plans should be prepared at the institutional

level

3. Accountability to the supervisory authority when radiation

incidents occur

Patient records

1. Doses should be documented

2. Images should be stored on a data repository that is accessible to

different facilities. This minimizes the unnecessary scans as

patient history can be reviewed

Results of non-

compliance

1. In the German Radiation Protection Ordinance, the support role

of the local medical authority is explained. A similar supporting

role and explanation should be defined by the supervisory

authority.

2. Sanctions should be explained in relation to the non-compliance

actions. The legal actions should be kept as available as a last

resort in non-compliance situations.

Dose

optimization-

related Themes

Operational

Requirements

1. Clinical justification for medical radiation exposure in order to

eliminate unnecessary CT exams, which includes specifications

for referral processes

2. ALARA-related standards (e.g. mandatory patient safety

measures are taken to ensure as low a dose as possible to

patients and staff)

3. Special populations should be accounted for (i.e. paediatrics and

pregnant females)

4. Review of new CT procedures by qualified professionals either at

the institutional level or jurisdictional level

Personnel

requirements

1. Duties, responsibilities and qualifications of the following

stakeholders, at a minimum: administrative responsible person,

designated responsible user, radiation safety officer, qualified

Page 168: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

147

technical expert (i.e. medical physicist), radiologist, radiation

technologist, manufacturer

2. Medical physicists should be added to the list of qualified

professionals to fulfill the role of radiation safety officer

3. Mandatory training programs and continuing professional

development activities

7.3.2.2 Possible Regulatory Approaches

There are four possible regulatory approaches that were identified through the analysis of the radiation

publication documents using RACT 2 and the thematic analysis of the expert interviews with

jurisdictional representatives, radiologists, and medical physicists. Each of the approaches has been

evaluated for their advantages and disadvantages, and their recommended implementation protocols have

been summarized in Table 24. It is recommended that Ontario select a minimum of one regulatory

approach. However, the most implementable and manageable approach is, perhaps, the mandatory

establishment of institutional radiation protection committees, which would ensure that every institution

is taking initiative to manage doses while allowing for flexibility and adaptability to the level of financial

and human resources available to an institution. Furthermore, Ontario can add diagnostic imaging exams

as a Quality-Based Procedure (QBP), which links institution funding to outcomes of care [162]. As a

QBP, Ontario will periodically assess each institution to ensure that the effectiveness, efficiency and

appropriateness of the diagnostic imaging procedures are continually being improved [162]. The addition

of diagnostic imaging as a QBP will also provide added incentive for the formation of proactive

institutional radiation protection committees.

The installation of dose monitoring software that extract data from the PACS system at a CT facility will

increase the efficiency of achieving compliance with any of the recommended approaches. For example,

an interviewee explained that Ireland has recently opted to subsidize the installation of dose monitoring

software at every CT facility, so DRLs can be developed with large datasets that are automatically

transmitted to a central server, which minimizes the human resources that would traditionally be required

from using dose surveys to establish DRLs. Dose monitoring software can also be used internally to

achieve compliance with the other proposed approaches. The automatic reports generated by dose monitor

software can reduce the time that each facility commits to comply with remote monitoring, and the

generation of dose trends can provide a data driven approach to adjusting CT protocols. Additionally,

ECRI Institute explained that the automatic recording for dose data can be used to investigate the cause of

unusually high or low doses and track individual patient exposure [8].

Page 169: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

148

Table 24: A summary of the possible dose optimization regulatory approaches that are available for Ontario's CT dose management regulations. The table summarizes the

advantages, disadvantages and recommended implementation protocol for each of the approaches.

Approach Advantages Disadvantages Recommended implementation protocol

Diagnostic

Reference

Levels

-Can potentially provide a

means to an incentives-

based system for CT

imaging in Ontario if dose

level comparisons are made

public

-Labour and financial

resource intensive

-Requires uniform data

collection and analysis

methodology across CT

facilities for accurate dose

level comparisons

-Traditional approach does

not account for patient

attenuation

-Inappropriate dose levels

may lead to repeated scans

and greater patient

exposures

-Define standard routine exams that should have established DRLs

-Review literature for official DRLs in other countries

-Preliminary dose data for Canada from dose surveys conducted by Health

Canada can be reviewed for current nation-wide dose distributions

-An effective approach to collect data is the implementation of a dose

monitoring software that complements the existing PACS system that is

installed in every Ontario CT facility, which can automatically transmit data

required for dose surveys, which would substantially decrease the amount

of time required.

-Periodic comparison of local DRLs against official DRLs can help to minimize

inappropriate reference doses for specific diagnostic exam types

-Optional: Require the establishment of institutional DRLs for comparison

purposes

-Optional: Consider the use of SSDEs instead of the CTDIvol and DLP for the

official DRL values

Compliance

Monitoring

-Less labour and financial

intensive than DRLs if

remote monitoring is

implemented

-Accountability to the

supervisory authority

ensures dose optimization

efforts at every facility

-Scheduled on-site

inspections do not

represent daily workflow

-A combination approach of on-site and remote monitoring

-Remote monitoring can be applied as random checks to reduce strain on

the supervisory authority

-Dose monitoring software can generate reports that meet the

requirements for remote monitoring while reducing the time commitment

of CT facilities to fulfill the standards of compliance monitoring

-Infrequent (~3-4 years) on-site inspections can increase dialogue with

individual facilities, and the problems within facilities that cannot be

detected through remote monitoring can be discussed

Peer Review -The use of existing image

repository servers makes

Option 1: Ontario-wide peer review

Use the image repository servers to share images and mandate the review

Page 170: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

149

this approach inexpensive

-Present learning

opportunities for the

radiology community as

knowledge sharing can

occur in cross-facility peer

reviews

-Accountability to the

supervisory authority

ensures dose optimization

efforts at every facility

of a pre-determined number of images during a specified timeframe by

every radiologist. The clinical diagnoses should be compared to ensure

consistency, but the comments should not be limited to the diagnoses.

Comments such as insufficient image quality, excessive dose, or clinical

inappropriateness should be encouraged. The radiologists that is responsible

for the image should be provided with a summary of the comments.

Option 2: Facility-wide peer review

Mandate the requirement for annual roundtables with all the radiologists.

The scanning protocols should be discussed and parameters adjusted during

the roundtables to ensure. Any problems with clinical workflows should also

be discussed. Committee should consist of all CT stakeholders, including a

professional who is knowledgeable in medical physics. Again, a mandated

dose monitoring software for every facility will increase the efficiency of this

process, as described by RP-1 in Section 7.2.4.3

Radiation

Safety

Committee

-Accountability to the

supervisory authority

ensures dose optimization

efforts at every facility

-Requires more patient

radiation protection

aspects to be addressed

compared to the peer

review approach

-May be labour intensive Similar to Option 2: Facility-wide peer review, but radiation safety

committees require the review and updates of more comprehensive quality

assurance (QA) plans.

-Committee should consist of all CT stakeholders, including a professional

who is knowledgeable in medical physics

-Target goals and indicators should be set in the QA plan

-Internal audits of the CT facility should be performed by the Radiation

Safety Committee to ensure good practice

-Results of the committee meeting and internal audits should be

documented and available for random checks by the supervisory committee

-Option should be provided for facilities to work together, so it is less

burdensome on smaller facilities

Page 171: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

150

7.5 Summary of CT Radiation Protection Model for Ontario

An achievable and comprehensive model for CT radiation protection regulations in Ontario was designed.

The model consisted of two parts: the minimum requirements and the possible regulatory approaches. The

minimum requirements, which is defined as the mandatory information that must be included in Ontario’s

new CT standards, were established from the key themes in the RACT 2 evaluations. There are two sub-

categories for minimum requirements of the CT dose management regulations in Ontario: general

requirements (i.e. general provisions, licensing, technical requirements, facility requirements, patient

records, emergency reporting, and results of non-compliance) and dose-optimization-related requirements

(i.e. operational requirements and personnel requirements).

Thematic analyses of the qualitative interview transcripts were performed to elicit recurring concepts that

provide insight into the possible dose optimization regulatory approaches, barriers and facilitators to

implementation of CT dose management regulations, and the priorities and concerns of CT stakeholders.

The possible dose optimization regulatory approaches, which were included in the second part of

Ontario’s CT radiation protection model, are DRLs, compliance monitoring, peer review and radiation

safety committee. It is recommended that a minimum of one dose optimization regulatory approach be

included in the CT dose management regulations. A detailed feasibility analysis is recommended to

accurately determine the costs and benefits as well as to evaluate the implications for sustainability of

each possible dose optimization regulatory approach. However, the following key steps should be taken to

initiate dose management efforts in Ontario.

Add medical physicists as qualified radiation safety officers for Ontario CT facilities

Detail continuing professional development standards that must be undertaken by every CT

stakeholder that wishes to be employed in Ontario

Form a multidisciplinary taskforce to discuss the design of optimal dose management regulations

in Ontario. This study did not contain the perspective of patients, who will be affected firsthand

by the regulations, but future discussions regarding regulations should include patients as a

stakeholder group.

The most implementable dose optimization approach is expected to be the mandate for

institutional radiation protection committees, which allows for the institutional approaches to be

adjusted according to financial and human resource availability while ensuring that doses are

gradually optimized over time.

Investigate the most efficient method to achieve compliance with the mandated approach at the

institutional level, such as the use of dose monitoring software

.

Page 172: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

151

8 Conclusion

The findings of this study are expected to contribute to the design of CT dose management regulations in

Ontario. Furthermore, the implications of this work on future research are discussed.

8.1 Summary of Findings

The use of ionizing radiation, which translates to increased cancer risks, in CT is a dangerous

complication in otherwise useful and powerful diagnostic tool. As reported by UNSCEAR, CT

contributes to about 35% of the collective dose for patients despite only accounting for 5% of clinical

procedures. In Canada, the number of operational CT scanners increased from 169 in 2004 to 510 in

2012. There is a clear need to prioritize CT dose management. The HARP Act is the official regulation in

Ontario that pertains to the operation of ionizing radiation in medical applications. However, the HARP

Act focuses on the technical aspects of CT equipment operation and does not provide sufficient

information on dose optimization measures that should be undertaken to minimize unnecessary radiation

exposures to patients. This study aimed to provide an achievable and comprehensive model for changes to

the CT radiation protection model in Ontario.

A widespread sample of jurisdictional models that regulate CT radiation protection that varies along

continuums of regulation strength, geography, healthcare system type and economic development was

selected for comparative analysis. The radiation protection publications of each jurisdiction were

reviewed, and qualitative interviews were conducted with jurisdictional representatives to gain a better

understanding of the regulatory structure and approach for CT dose management. International

organizations, such as the IAEA or Euratom, with keen interests in radiation protection were observed to

have an influence on the regulatory approaches in the independent countries and/or states. Despite the

best interest of the Euratom, the rigorous standards in Council Directive 97/43/Euratom were unrealistic

for member states with lower levels of financial and human resource including Portugal and Ireland.

However, the effectiveness of the approach was witnessed by other jurisdictions like Australia who opted

to adopt similar CT standards. The European approaches that were countrywide regulations were revealed

to be more centralized, and therefore, easier to implement and monitor in comparison to the disjointed

regulatory structure in the North American states. Texas, California and British Columbia, in particular,

has established CT specific regulations to manage patient doses although the approaches were observed to

be less demanding in its expectations than the European counterparts. Although developing jurisdictions

like Kenya has a low number of CT scanners within its country, it still designed minimal licensing

regulations to oversee CT facilities. Every jurisdiction, whether it has few resources or abundant

Page 173: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

152

resources, was observed to have made an effort to ensure radiation protection of patients from ionizing

radiation in medical applications. Ontario, likewise, is expected to benefit from adoption of CT dose

management standards that has been customized to the financial and human resource availability of the

province.

RACT 2, an assessment instrument that provided an effective and easy to use method of systematically

comparing and evaluating the quality of each jurisdictional regulatory approach as described in radiation

protection documents, was developed. A pilot study on six jurisdictions was performed using the first

iteration of the instrument, RACT 1, to identify the limitations and to streamline the design. RACT 1’s

division of themes and domains were ambiguous and resulted in low inter-rater reliability ratings. The use

of Likert Scales was found to decrease the inter-rater reliability because ordinal measurements require a

level of judgement. Reviewers agreed that subsequent iterations should maximize the use of quantitative

assessments. Furthermore, RACT 1 combined the different document types for analysis, which eliminated

critical attributes that are influential in the development and usage of legislation or supplemental

documents.

The second iteration, RACT 2, corrected for the limitations found from the pilot study of RACT 1. RACT

2 was designed with three parts: comprehensiveness checklist, legislation quality assessment and

supplemental quality assessment. There was a saturation of themes and sub-themes in the thematic

analysis applied to generate the comprehensiveness checklist, and so, they are expected to be applicable

to any jurisdictional CT radiation protection publication. Two literature searches were performed to find

the key domains in legislation quality and supplemental document quality, respectively. The legislation

quality assessment had six domains: clarity and presentation of legislative scope, transparency,

accountability, rigor of compliance requirements, outcomes or non-compliance and fairness, while the

supplemental document quality assessment had seven domain: clarity of scope and purpose, evidence

support, instructive quality of writing, adaptability, integration of inter-professional perspectives, rigor of

expectations and rigor of updates. RACT 2 was designed to be used by a minimum of two independent

reviewers during comparative evaluations of jurisdictional CT radiation protection models. Inter-rater

reliability, as determined by Weighted Cohen’s Kappa, for the legislation and supplemental document

quality assessments should be at least 0.75 to show a satisfactory level of agreement between reviewers.

Comparative evaluations of the 13 selected jurisdictions were performed using RACT 2 were performed,

and a high level comparison of the dose data from each jurisdiction was conducted. The general

provisions theme was found to be important for both legislation and supplemental documents because it

Page 174: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

153

sets the tone for the reader and ensures similar levels of comprehension amongst intended users.

Consistent dose optimization sub-themes were identified as clinical justification for medical exposures

and ALARA-related standards, which suggests that regulations aimed at CT dose management should

include at least one of the encompassed key items from these sub-themes. The highest average scoring

domain for both the legislation and supplemental quality assessment was the clarity and presentation of

the scope in both legislation and supplemental, which suggests jurisdictions paid the most attention to

ensure high performance in this critical attribute. After the clarity of scope and purpose, the key domains

that affect legislation quality were identified as rigor of compliance and outcomes of compliance. Both

domains focused on oversight measures by the supervisory authority that are designed to improve the

confidence of patients using CT facilities. Contrastingly, the other key domain that affect supplemental

document quality was determined to be the instructive quality of writing, which align with the purpose of

the documents to provide additional details that help users achieve compliance with legal standards.

Furthermore, the highest scoring legislation and supplemental document in both comprehensiveness and

quality were the Texan Radiation Control Act and IAEA’s Basic Safety Standards, respectively. Texas’s

Radiation Control Act is supplemented by six subsidiary administrative codes that also have legal

authority, and so, this set-up appeared to provide sufficient information for high implementability of the

standards.

The approximate dose level comparisons were divided into two sections: official DRLs and peer-

reviewed dose data. A broad comparison of jurisdictions with proposed or established DRLs revealed that

Germany, Ireland, Australia, Switzerland, the UK and Portugal all have comparable DRL values that

together were systematically lower than other jurisdictional proposed or existing DRLs. These six

countries were defined as “strong” jurisdictions for the study. Comparatively, the countries that had

systematically higher proposed DRLs were Japan and Kenya, and therefore, classified as “weak”

jurisdictions. A general relationship analysis between the evaluations from RACT 2 and the dose level

comparisons revealed that jurisdictions with more rigorous compliance standards (i.e. the strong

jurisdictions) had systematically lower DRL values, which were uniformly defined by the countries as the

75th percentile value of the dose data distribution. Japan, contrastingly, does not have any regulations

pertaining to the operation of CT scanners, and Kenya only has minimal licensing requirements for the

CT facilities within the country. Ontario’s preliminary dose data from three institutions were

inappropriate for inclusion in the comparison of proposed and official DRLs but the high mean CTDIvol

and DLP values recorded for head and abdo-pelvis exams provided a glimpse of the less successful

regulatory approach in Ontario. Jurisdictional regulatory approaches modelled after the strong

Page 175: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

154

jurisdictions’ frameworks is expected to provide more awareness of dose optimization at the institutional

level, which results in lower jurisdiction-wide dose distributions.

The comparative analysis of the radiation protection publications using RACT 2, the relationship analysis

of the regulatory structure and the approximate dose level comparisons and qualitative interviews with

jurisdictional representatives, radiologists and medical physicists were considered in the development of a

strategic framework for an achievable and comprehensive CT dose management regulations in Ontario.

The model consisted of two sections: minimum requirements and possible dose-optimization regulatory

approaches. The minimum requirements contained the general themes of general provisions, technical

requirements, facility requirements, emergency situations and event reporting, patient records and results

of non-compliance, as well as specific dose-optimization related themes of operational and personnel

requirements. Specifically, the operational requirements should contain standards for clinical justification

for medical exposure and referral processes, ALARA-related standards, special considerations for

paediatric and pregnant patients, and review of new CT procedures by qualified professionals.

The possible specific dose optimization-related regulatory approaches were implementation of DRLs,

compliance monitoring, peer review requirements and radiation safety committees. It is recommended

that a minimum of one dose-optimization specific approach be adopted into the CT radiation protection

regulations in Ontario. The most implementable approach for Ontario is the mandated establishment of

institutional radiation protection committees, which offers both flexibility and adaptability. The addition

of diagnostic imaging processes as a QPB may provide added incentive for institutions to initiate dose

management approaches. Furthermore, dose monitoring software have been recommended as a useful tool

for CT facilities to achieve compliance with any of the recommended dose optimization approaches in a

more efficient manner because of its ability to automatically generate reports and dose trends in addition

to automatically transmitting data to a central server to establish jurisdiction-wide DRLs. The amount of

financial and human resources required for sustainability, the possibility of incentives and the adaptability

of the approach should be considered for smoother clinical uptake, as these were the greatest concerns

from Ontario radiologists and medical physicists. Furthermore, the design process for the regulations

should involve all CT stakeholders as acceptance and engagement amongst the targeted users has been

shown to increase implementability of new CT dose management regulations.

8.2 Anticipated Significance

The significance of this work is threefold in its application to the theoretical and applied knowledge of the

radiation protection field. Firstly, the development of RACT 2 provides an effective and easy to use

Page 176: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

155

method to systematically evaluate and compare jurisdictional radiation protection publications for CT

radiation protection. Although iterations and refinements are required as explained in the limitations of

Section 5.3.3, the specialized instrument is a step forward in the appraisal of the intended jurisdictional

regulatory approaches for CT dose management. Furthermore, parts 2 and 3 can be used independently

for the evaluation of legislation and supplemental documents, such as clinical guidelines, quality. These

quality assessment tools can be used as part of the overall quality mandate aimed to improve

policymaking in healthcare.

The second contribution of this work is the large-scale review of jurisdictional CT dose management

regulations, which provides a comprehensive and easily accessible tool for the appraisal and comparison

of jurisdictional approaches. The analysis of relationships between jurisdictional dose management

approaches and general dose trends offered preliminary insight into the minimum requirements that are

required in the oversight of CT to optimize dose at the institutional level. The implementation of these

requirements into existing CT radiation protection regulations for countries with high dose distributions is

expected to raise awareness of CT stakeholders, which can potentially result in the systematic adjustments

of scanning protocols to lower radiation exposure of patients. This will ultimately improve patient safety.

Finally, the thematic analysis results of the semi-structured interviews with jurisdictional representatives,

radiologists and medical physicists can offer guidance to the regulatory authorities who are interested in

designing dose management regulations within their respective jurisdictions. The experiences and lessons

learned from jurisdictions who have embarked on similar exercises to regulate CT radiation protection

provide invaluable insight into the steps that should be taken to ensure smooth uptake of new standards at

the institutional level. Changes in CT radiation protection standards will inevitably affect clinical practice

and workflows, which is likely to experience criticism from institutional CT stakeholders. The concerns

and perspectives of Ontario CT stakeholders that were elicited through the interviews offer specific

considerations for the design of Ontario’s rendition of CT dose management regulations, which can

potentially minimize resistance and improve implementability. The adoption of the recommendations

from the CT radiation protection model in Ontario can optimize CT patient safety by minimizing

incidences of cancer attributed to unnecessary radiation exposure from diagnostic CT examinations.

8.3 Future Work

There are several opportunities for further research due to the limitations of this study. As discussed in

Section 6.3.4, further research should refine RACT 2 to include a method of analysis for the overall

regulatory structure of each jurisdiction. This will involve the development of a means to combine the

Page 177: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

156

results of the legislation and supplemental document evaluations. Secondly, future work can compare and

investigate alternative methods, whether qualitative or quantitative, to account for the critical differences

in similar regulatory frameworks because significant difference between the jurisdictions’ domain scores

cannot be shown with the current use of the 5-point Likert Scale in RACT 2.

Future research is also required to accurately validate the RACT instrument. The required work to

validate RACT 2 is two-fold. Firstly, accurate dose level comparisons need to be performed. As described

in Section 6.2.3, this would involve employment of uniform data collection and analysis methodologies.

For example, consistent correction factors should be applied for each scanner type. Furthermore, the

definition of the compared exam types need to be well-defined, which can be achieved by providing

participants with specific clinical indications encompassed by each exam type and the analysis of

acquisition parameters by protocol. Secondly, the results of the dose comparisons will need to be

correlated with the domain and theme scores of each jurisdiction to validate the RACT instrument. This

would confirm the key domains and themes that are influential in the prioritization of dose optimization

within a jurisdiction.

Page 178: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

157

9 References

[1] P. H. Fung Kon Jin, A. R. van Geene, K. F. Linnau, G. J. Jurkovich, K. J. Ponsen, and J. C.

Goslings, "Time factors associated with CT scan usage in trauma patients," Eur J Radiol, vol. 72,

pp. 134-8, Oct 2009.

[2] N. Stoodley and P. Shoba. (2011, CT Scan: Friend or Foe? Clinical Risk 17(4), 134-136.

[3] "Medical Imaging in Canada 2012," M. Imaging, Ed., ed: Canadian Institute for Health

Information 2012.

[4] D. J. Brenner, "Should we be concerned about the rapid increase in CT usage?," Rev Environ

Health, vol. 25, pp. 63-8, 2010 Jan-Mar 2010.

[5] M. S. Parker. (2010, Patient Radiation Dose Reduction Strategies for CT Imaging. Contemporary

Diagnostic Radiology 33(7), 1-5.

[6] M. B. Williams, E. A. Krupinski, K. J. Strauss, W. K. Breeden, M. S. Rzeszotarski, K. Applegate,

et al., "Digital radiography image quality: image acquisition," J Am Coll Radiol, vol. 4, pp. 371-

88, Jun 2007.

[7] M. K. Karla, M. M. Maher, T. L. Toth, L. M. Hamberg, M. A. Blake, J.-A. Shepard, et al.,

"Strategies for CT Radiation Dose Optimization," Radiology, vol. 230, pp. 619-628, 2004.

[8] "Optimizing CT dose," Health Devices, vol. 41, pp. 238-49, Aug 2012.

[9] "CT Radiation Dose," Health Devices, pp. 109-125 2010.

[10] J. D. Mathews, A. V. Forsythe, Z. Brady, M. W. Butler, S. K. Goergen, G. B. Byrnes, et al.,

"Cancer risk in 680,000 people exposed to computed tomography scans in childhood or

adolescence: data linkage study of 11 million Australians," BMJ, vol. 346, p. f2360, 2013.

[11] "Canadian Cancer Statistics 2013," Canadian Cancer Society, Toronto, ON2013.

[12] S. J. Foley, M. F. McEntee, and L. A. Rainford, "Establishment of CT diagnostic reference levels

in Ireland," Br J Radiol, vol. 85, pp. 1390-7, Oct 2012.

[13] "Hospitals- Management and Use of Diagnostic Imaging Equipment," Office of the Auditor

General, Ontario2006.

Page 179: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

158

[14] A. K. Hara, C. V. Wellnitz, R. G. Paden, W. Pavlicek, and D. V. Sahani, "Reducing body CT

radiation dose: beyond just changing the numbers," AJR Am J Roentgenol, vol. 201, pp. 33-40,

Jul 2013.

[15] M. M. Rehani, "Challenges in radiation protection of patients for the 21st century," American

Journal of Roentgenology, vol. 200, pp. 762-764, 2013.

[16] S. Ulzheimer and T. Flohr, "Multislice CT: current technology and future developments," in

Multislice CT, ed: Springer, 2009, pp. 3-23.

[17] L. W. Goldman, "Principles of CT and CT technology," Journal of nuclear medicine technology,

vol. 35, pp. 115-128, 2007.

[18] G. Wang, Y. Liu, Y. Ye, S. Zhao, J. Hsieh, and S. Ge, "Top-level design and preliminary physical

analysis for the first electron-beam micro-CT scanner," Journal of X-Ray Science and

Technology, vol. 12, pp. 251-260, 2004.

[19] T. G. Flohr, C. H. McCollough, H. Bruder, M. Petersilka, K. Gruber, C. Süβ, et al., "First

performance evaluation of a dual-source CT (DSCT) system," European radiology, vol. 16, pp.

256-268, 2006.

[20] T. Henzler, C. Fink, S. O. Schoenberg, and U. J. Schoepf, "Dual-energy CT: radiation dose

aspects," American Journal of Roentgenology, vol. 199, pp. S16-S25, 2012.

[21] M. K. Kalra, M. M. Maher, T. L. Toth, L. M. Hamberg, M. A. Blake, J. A. Shepard, et al.,

"Strategies for CT radiation dose optimization," Radiology, vol. 230, pp. 619-28, Mar 2004.

[22] P. Frame. (2009, August 6). Coolidge X-ray Tubes - General Information. Available:

https://www.orau.org/ptp/collection/xraytubescoolidge/coolidgeinformation.htm

[23] T. Flohr and B. Ohnesorge, "Multi-slice CT Technology," in Multislice CT, ed: Springer, 2009,

pp. 41-69.

[24] T. G. Flohr, S. Schaller, K. Stierstorfer, H. Bruder, B. M. Ohnesorge, and U. J. Schoepf, "Multi–

Detector Row CT Systems and Image-Reconstruction Techniques 1," Radiology, vol. 235, pp.

756-773, 2005.

[25] A. Kopp, K. Klingenbeck-Regn, M. Heuschmid, A. Kuttner, B. Ohnesorge, T. Flohr, et al.,

"Multislice computed tomography: basic principles and clinical applications,"

ELECTROMEDICA-ERLANGEN-, vol. 68, pp. 94-105, 2000.

Page 180: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

159

[26] S. W. Smith, "Special Imaging Techniques-Computed Tomography," in The Scientist and

Engineer's Guide to Digital Signal Processing, ed San Diego: California Technical Publishing,

1997.

[27] T. Peters, "CT image reconstruction," SLIDES REVL, pp. 05697-05745, 2002.

[28] X. Pan, E. Y. Sidky, and M. Vannier, "Why do commercial CT scanners still employ traditional,

filtered back-projection for image reconstruction?," Inverse problems, vol. 25, p. 123009, 2009.

[29] Health Risks from Exposure to Low Levels of Ionizing Radiation BEIR VII Phase 2. Washington,

DC: The National Academies Press, 2006.

[30] R. S. S. Viana, E. A. da Fonseca Lima, H. de Oliveira Florentino, P. R. de Fonseca, and T. P. D.

Homem, "Heterogeneity correction in the construction of optimized planning in radiotherapy

using linear programming," Pesquisa Operacional, vol. 31, 2011.

[31] J. R. K. Savage and J. D. Tucker, "Nomenclature systems for FISH-painted chromosome

aberrations," Mutation Research/ Reviews in Genetic Toxicology, vol. 366, pp. 153-161, 1996.

[32] S. A. Amundson, F. Xia, K. Wolfson, and H. L. Liber, "Different cytotoxic and mutagenic

responses induced by X-rays in two human lymphoblastoid cell lines derived from a single

donor," Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, vol. 286,

pp. 233-241, 1993.

[33] M. J. Difilippantonio, S. Petersen, H. T. Chen, R. Johnson, M. Jasin, R. Kanaar, et al., "Evidence

for Replicative Repair of DNA Double-Strand Breaks Leading to Oncogenic Translocation and

Gene Amplification," Journal of Experimental Medicine, vol. 196, pp. 469-480, 2002.

[34] C. H. McCollough, S. Leng, L. Yu, D. D. Cody, J. M. Boone, and M. F. McNitt-Gray, "CT dose

index and patient dose: they are not the same thing," Radiology, vol. 259, pp. 311-316, 2011.

[35] J. A. Bauhs, T. J. Vrieze, A. N. Primak, M. R. Bruesewitz, and C. H. McCollough, "CT

Dosimetry: Comparison of Measurement Techniques and Devices 1," Radiographics, vol. 28, pp.

245-253, 2008.

[36] C. H. McCollough, A. N. Primak, N. Braun, J. Kofler, L. Yu, and J. Christner, "Strategies for

Reducing Radiation Dose in CT," Radiology Clinics of North America, vol. 47, pp. 27-40, 2009.

[37] W. Huda and F. A. Mettler, "Volume CT Dose Index and Dose-Length Product Displayed during

CT: What Good Are They? 1," Radiology, vol. 258, pp. 236-242, 2011.

Page 181: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

160

[38] W. Huda, K. M. Ogden, and M. R. Khorasani, "Converting Dose-Length Product to Effective

Dose at CT 1," Radiology, vol. 248, pp. 995-1003, 2008.

[39] M. McNitt-Gray and F. DABR, "Assessing radiation dose: how to do it right," in AAPM 2011

Summit on CT dose available via http://www.aapm.org/meetings/2011CTS/documents/McNitt-

GrayAssessingRadiationdoseFINAL. pdf# search=’McNittGray+ M. Assessing+ radiation+

dose% 3A+ how+ to+ do+ it+ right’. Accessed, 2013.

[40] P. D. Deak, Y. Smal, and W. A. Kalender, "Multisection CT Protocols: Sex- and Age-specific

Conversion Factors Used to Determine Effective Dose from Dose-Length Product," Radiology,

vol. 257, pp. 158-166, 2010.

[41] C. A. Coursey and D. P. Frush, "CT and Radiation: What radiologists should know," Applied

Radiology, vol. 37, pp. 22-29, 2008.

[42] K. C. Lai and D. P. Frush, "Managing the Radiation dose from pediatric CT," Applied Radiology,

vol. 35, pp. A13-A20, 2006.

[43] (2010, April) CT Radiation Dose. Health Devices. 110-125.

[44] C. H. McCollough, A. N. Primak, N. Braun, J. Kofler, L. Yu, and J. Christner, "Strategies for

reducing radiation dose in CT," Radiol Clin North Am, vol. 47, pp. 27-40, Jan 2009.

[45] J. E. Wilting, A. Zwartkruis, M. S. van Leeuwen, J. Timmer, A. G. Kamphuis, and M. Feldberg,

"A rational approach to dose reduction in CT: individualized scan protocols," Eur Radiol, vol. 11,

pp. 2627-32, 2001.

[46] G. M. Israel, S. Herlihy, A. N. Rubinowitz, D. Cornfeld, and J. Brink, "Does a combination of

dose modulation with fast gantry rotation time limit CT image quality?," AJR Am J Roentgenol,

vol. 191, pp. 140-4, Jul 2008.

[47] M. A. Morgan and U. Bashir. (2015). Pitch | Radiology Reference Article | Radiopaedia.org.

Available: http://radiopaedia.org/articles/pitch

[48] L. Yu, X. Liu, S. Leng, J. M. Kofler, J. C. Ramirez-Giraldo, M. Qu, et al., "Radiation dose

reduction in computed tomography: techniques and future perspective," Imaging in medicine, vol.

1, pp. 65-84, 2009.

[49] Y. Nakayama, K. Awai, Y. Funama, M. Hatemura, M. Imuta, T. Nakaura, et al., "Abdominal CT

with low tube voltage: preliminary observations about radiation dose, contrast enhancement,

image quality, and noise 1," Radiology, vol. 237, pp. 945-951, 2005.

Page 182: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

161

[50] D. Marin, R. C. Nelson, E. Samei, E. K. Paulson, L. M. Ho, D. T. Boll, et al., "Hypervascular

Liver Tumors: Low Tube Voltage, High Tube Current Multidetector CT during Late Hepatic

Arterial Phase for Detection—Initial Clinical Experience 1," Radiology, vol. 251, pp. 771-779,

2009.

[51] "Computed Tomography Radiation Safety," Center for Global eHealth Innovation, University

Health Network, Toronto, Ontario2006.

[52] "Clinical Practice Parameters and Facility Standards: Computed Tomography 2nd Edition," The

College of Physicians & Surgeons of Ontario, Toronto, Ontario2009.

[53] M. K. Kalra, M. M. Maher, T. L. Toth, B. Schmidt, B. L. Westerman, H. T. Morgan, et al.,

"Techniques and Applications of Automatic Tube Current Modulation for CT 1," Radiology, vol.

233, pp. 649-657, 2004.

[54] M. C. Rehani, M. Kalra, C. McCollough, H. D. Nagel, L. Collins, and W. Kalender, "Managing

patient dose in multi-detector computed tomogrpahy (MDCT)," I. C. o. R. Protection, Ed., ed,

2006.

[55] T. Y. Lee and R. K. Chhem, "Impact of new technologies on dose reduction in CT," Eur J Radiol,

vol. 76, pp. 28-35, Oct 2010.

[56] J. Hausleiter, T. S. Meyer, E. Martuscelli, P. Spagnolo, H. Yamamoto, P. Carrascosa, et al.,

"Image quality and radiation exposure with prospectively ECG-triggered axial scanning for

coronary CT angiography: the multicenter, multivendor, randomized PROTECTION-III study,"

JACC: Cardiovascular Imaging, vol. 5, pp. 484-493, 2012.

[57] W. P. Shuman, K. R. Branch, J. M. May, L. M. Mitsumori, D. W. Lockhart, T. J. Dubinsky, et

al., "Prospective versus Retrospective ECG Gating for 64-Detector CT of the Coronary Arteries:

Comparison of Image Quality and Patient Radiation Dose 1," Radiology, vol. 248, pp. 431-437,

2008.

[58] S. Itoh, S. Koyama, M. Ikeda, M. Ozaki, A. Sawaki, S. Iwano, et al., "Further reduction of

radiation dose in helical CT for lung cancer screening using small tube current and a newly

designed filter," J Thorac Imaging, vol. 16, pp. 81-8, Apr 2001.

[59] T. Beaconsfield, R. Nicholson, A. Thornton, and A. Al-Kutoubi, "Would thyroid and breast

shielding be beneficial in CT of the head?," Eur Radiol, vol. 8, pp. 664-7, 1998.

[60] N. Hidajat, R. J. Schröder, T. Vogl, H. Schedel, and R. Felix, "[The efficacy of lead shielding in

patient dosage reduction in computed tomography]," Rofo, vol. 165, pp. 462-5, Nov 1996.

Page 183: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

162

[61] D. Bawden and L. Robinso, "The dark side of information: overload, anxiety, and other

paradoxes and pathologies," Journal of Information Science, vol. 35, pp. 180-191, 2009.

[62] C. H. McCollough, J. Wang, R. G. Gould, and C. G. Orton "The use of bismuth breast shields for

CT should be discouraged," Medical Physics, vol. 39, p. 2321, 2012.

[63] K. J. Strauss, M. J. Goske, S. C. Kaste, D. Bulas, D. P. Frush, P. Butler, et al., "Image gently: Ten

steps you can take to optimize image quality and lower CT dose for pediatric patients," AJR Am J

Roentgenol, vol. 194, pp. 868-73, Apr 2010.

[64] S. H. Woolf, R. Grol, A. Hutchinson, M. Eccles, and J. Grimshaw, "Potential benefits,

limitations, and harms of clinical guidelines," British Medical Journal, vol. 318, pp. 527-530,

1999.

[65] M. Dobbins, D. Ciliska, R. Cockerill, J. Barnsley, and A. DiCenso, "A Framework for the

Dissemination and Utilization of Research for Health-Care Policy and Practice," The Online

Journal of Knowledge Synthesis for Nursing vol. 9, p. Document 7, 2002.

[66] M. M. Rehani, "What Makes and Keeps Radiation Risks Associated With CT a Hot Topic?,"

American Journal of Roentgenology, 2015.

[67] "European Commission - PRESS RELEASES - Press release - Radiation: The Commission takes

France, Germany, Ireland, The Netherlands, Portugal and the United Kingdom to Court for non-

transposition of EU laws," ed. Brussels: European Commission Press Release Database, 2002, p.

IP/02/412.

[68] "Council Directive 97/43/Euratom on health protection of individuals against the dangers of

ionizing radiation in relation to medical exposure," vol. L 180, ed. European Atomic Energy

Community: Official Journal of the European Union, 1997, pp. 0022-0027.

[69] "Chapter 4.2: Medical Technologies (Supply and Use)," in Health at a Glance 2009: OECD

Indicators, ed Paris: OECD Publishing, 2009, pp. 92-93.

[70] "Chapter 4.2: Medical Technologies," in Health at a Glance 2013: OECD Indicators, ed Paris:

OECD Publishing, 2013, pp. 86-87.

[71] World Health Organization, "Baseline country survey on medical devices 2010," 2011.

[72] (2015, Aug 10). Legislation. Available: http://ec.europa.eu/legislation/index_en.htm

Page 184: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

163

[73] Bora Laskin Law Library. (2015). Step 2: Primary Sources of Law: Canadian Legislation | Bora

Laskin Law Library. Available: http://library.law.utoronto.ca/step-2-primary-sources-law-

canadian-legislation

[74] L. C. Engel, A. M. Lee, H. Seifarth, M. S. Sidhu, T. J. Brady, U. Hoffmann, et al., "Weekly dose

reports: the effects of a continuous quality improvement initiative on coronary computed

tomography angiography radiation doses at a tertiary medical center," Acad Radiol, vol. 20, pp.

1015-23, Aug 2013.

[75] J. S. AlSuwaidi, L. G. AlBalooshi, H. M. AlAwadhi, A. Rahanjam, M. A. ElHallag, J. S. Ibrahim,

et al., "Continuous monitoring of CT dose indexes at Dubai Hospital," American Journal of

Roentgenology, vol. 201, pp. 858-864, 2013.

[76] Safety Procedures for the Installation, Use and Control of X-ray Equipment in Large Medical

Radiological Facilities, H. Canada, 2008.

[77] "Computed Tomography (CT) Safety Initiave," Ministry of Health and Long-Term Care,

Toronto, Ontario2011.

[78] "Healing Arts Radiation Protection Act R.R.O 1990, Regulation 542 X-ray Safety Code,"

Ministry of Health and Long-Term Care, Toronto, Ontario2011.

[79] The World Bank Group. (2015, AUG 14). Country and Lending Groups | Data. Available:

http://data.worldbank.org/about/country-and-lending-groups#East_Asia_and_Pacific

[80] K. S. Khan, R. Kunz, J. Kleijnen, and G. Antes, "Five steps to conducting a systematic review," J

R Soc Med, vol. 96, pp. 118-21, Mar 2003.

[81] M. Sandelowski, "Focus on research methods-whatever happened to qualitative description?,"

Research in nursing and health, vol. 23, pp. 334-340, 2000.

[82] C. Pope, S. Ziebland, and N. Mays, "Qualitative research in health care: Analysing qualitative

data," BMJ: British Medical Journal, vol. 320, p. 114, 2000.

[83] R. A. Howard and J. E. Matheson, "Influence diagrams," Decision Analysis, vol. 2, pp. 127-143,

2005.

[84] P. Mathijsen, "Problems Connected with the Creation of EURATOM," Law and Contemporary

Problems, pp. 438-453, 1961.

[85] E. Commission. (2015, Aug 16). Euratom - Horizon 2020 - European Commission. Available:

http://ec.europa.eu/programmes/horizon2020/en/h2020-section/euratom

Page 185: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

164

[86] Association of State and Territorial Health Officials, "State Public Health Agency Classification:

Understanding the Relationship Between State and Local Public Health," Arlington, VA: 2012.

[87] "The Radiation Protection Act," Legislative Assembly of Manitoba, 4th ed, 2015.

[88] R. Mohd-Nor, "Medical Imaging Trends and Implementation: Issues and Challenges in

Developing Countries," Journal of Health Informatics in Developing Countries, vol. 5, pp. 89-98,

2011.

[89] Okon Medical Physics Foundation. (2015, Aug 16). PAC0RI, Kenya 2015 - and the launch of

AFROSAFE :: OkonMedPhys. Available: http://www.okonmed.com/blog/2015/02/20/awareness-

on-medical-physics%E2%80%99-role/

[90] International Society of Radiology Commission on Radiological Quality and Safety. Safety.

(2015, Newsletter. (July 2015).

[91] Organization for Economic Co-operation and Development Nuclear Energy Agency, "Regulatory

and Instiutional Framework for Nuclear Activities-Japan," 2010.

[92] (2015, Aug 16). Medical Exposure Research Project | Center and Research core | National

Institute of Radiological Science. Available: http://www.nirs.go.jp/ENG/core/merp/merp.shtml

[93] World Health Organization, "Radiological protection for medical exposure to ionizing radiation.

Safety guide," 2004.

[94] E. H. Bradley, L. A. Curry, and K. J. Devers, "Qualitative data analysis for health services

research: developing taxonomy, themes, and theory," Health Serv Res, vol. 42, pp. 1758-72, Aug

2007.

[95] "Clinical Practice guidelines We Can Trust," The National Academies Press, Washington, D.C.,

Guidelines2011.

[96] R. N. Shiffman, J. Dixon, C. Brandt, A. Essaihi, A. Hsiao, G. Michel, et al., "The GuideLine

Implementability Appraisal (GLIA): development of an instrument to identify obstacles to

guideline implementation," BMC Med Inform Decis Mak, vol. 5, p. 23, 2005.

[97] M. C. Brouwers, M. E. Kho, G. P. Browman, J. S. Burgers, F. Cluzeau, G. Feder, et al., "AGREE

II: advancing guideline development, reporting and evaluation in health care," CMAJ, vol. 182,

pp. E839-42, Dec 2010.

[98] G. R. Hall, "Statutory interpretation in the Supreme Court of Canada: the triumph of a common

law methodology," Advocates' Quarterly, vol. 21, pp. 38-65, 1998.

Page 186: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

165

[99] S. Jamieson, "Likert scales: how to ab(use) them," Medical Education, vol. 38, pp. 1217-1218,

2004.

[100] International Atomic Energy Agency. (2015, Aug 18). Diagnostic Reference Levels (DRLs) in

CT. Available:

https://rpop.iaea.org/RPOP/RPoP/Content/InformationFor/HealthProfessionals/1_Radiology/Com

putedTomography/diagnostic-reference-levels.htm#DRLCT-FAQ02

[101] C. Coglianese, "Measuring Regulatory Performance Evaluating the Impact of Regulation and

Regulatory Policy," 2012.

[102] V. Aitken, "An exposition of legislative quality and its relevance for effective development," ed:

Loyola University Chicago, 2013, pp. 1-43.

[103] G. A. Bowen, "Naturalistic inquiry and the saturation concept: a research note," Qualitative

research, vol. 8, pp. 137-152, 2008.

[104] C. Radaelli and O. Fritsch, "Evaluating Regulatory Management Tools and Programmes," ed:

Organisation for Economic Co-operation and Development, 2012.

[105] D. Parker and C. Kirkpatrick, "The Economic Impact of Regulatory Policy: A Literature Review

of Quantitative Evidence," ed: Organization for Economic Co-operation and Development, 2012,

pp. 1-47.

[106] "Guide to Making Federal Acts and Regulations," D. o. J. Canada, Ed., 2 ed: Government of

Canada Privy Council Office, 2001.

[107] M. Johnston, "Good Governance: Rule of Law, Transparency, and Accountability," ed. New

York: United Nations Public Administration Network.

[108] "A Framework for Analyzing Public Policies: Practical Guide," N. C. C. f. H. P. Policy, Ed., ed.

Quebec: Instiut national de sante publique Quebec, 2012.

[109] (2015, March 5). About Systematic Evidence Reviews and Clinical Practice Guidelines - NHLBI,

NIH. Available: http://www.ncbi.nlm.nih.gov/pubmed/

[110] (2014). More About Knowledge Translation at CIHR - CIHR. Available: http://www.cihr-

irsc.gc.ca/e/39033.html

[111] S. E. Straus, J. Tetroe, and I. Graham, "Defining knowledge translation," Canadian Medical

Association Journal, vol. 181, pp. 165-168, 2009.

Page 187: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

166

[112] R. Landry, N. Amara, A. Pablos-Mendes, R. Shademani, and I. Gold, "The knowledge-value

chain: A conceptual framework for knowledge translation in health," Bull World Health Organ,

vol. 84, pp. 597-602, Aug 2006.

[113] M. J. Metzler and G. A. Metz, "Analyzing the barriers and supports of knowledge translation

using the PEO model," Canadian Journal of Occupational Therapy, vol. 77, pp. 151-158, 2010.

[114] C. Muntaner, H. Chung, K. Murphy, and E. Ng, "Barriers to knowledge production, knowledge

translation, and urban health policy change: ideological, economic, and political considerations,"

Journal of Urban Health, vol. 89, pp. 915-924, 2012.

[115] J. M. Grimshaw, M. P. Eccles, J. N. Lavis, S. J. Hill, and J. E. Squires, "Knowledge translation of

research findings," Implement Sci, vol. 7, p. 50, 2012.

[116] U. Siering, M. Eikermann, E. Hausner, W. Hoffmann-Eßer, and E. A. Neugebauer, "Appraisal

tools for clinical practice guidelines: A systematic review," 2013.

[117] T. M. Shaneyfelt, M. F. Mayo-Smith, and J. Rothwangl, "Are guidelines following guidelines?:

The methodological quality of clinical practice guidelines in the peer-reviewed medical

literature," Jama, vol. 281, pp. 1900-1905, 1999.

[118] R. Grol, J. Dalhuijsen, S. Thomas, G. Rutten, and H. Mokkink, "Attributes of clinical guidelines

that influence use of guidelines in general practice: observational study," Bmj, vol. 317, pp. 858-

861, 1998.

[119] M. Kastner, O. Bhattacharyya, L. Hayden, J. Makarski, E. Estey, L. Durocher, et al., "Guideline

uptake is influenced by six implementability domains for creating and communicating guidelines:

a realist review," Journal of clinical epidemiology, vol. 68, pp. 498-509, 2015.

[120] H. Balshem, M. Helfand, H. J. Schünemann, A. D. Oxman, R. Kunz, J. Brozek, et al., "GRADE

guidelines: 3. Rating the quality of evidence," Journal of clinical epidemiology, vol. 64, pp. 401-

406, 2011.

[121] M. K. Burns, "How to establish interrater reliability," Nursing, vol. 44, pp. 56-58, 2014.

[122] G. Norman, "Likert scales, levels of measurement and the “laws” of statistics," Advances in

Health Sciences Education, vol. 15, pp. 625-632, 2010.

[123] N. Wongpakaran, T. Wongpakaran, D. Wedding, and K. L. Gwet, "A comparison of Cohen’s

Kappa and Gwet’s AC1 when calculating inter-rater reliability coefficients: a study conducted

with personality disorder samples," Biomed Central Medical Research Methodology, vol. 13,

2013.

Page 188: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

167

[124] "Health Professions Act," ed. British Columbia, 1996.

[125] Australian Radiation Protection and Nuclear Safety Agency. (2015, Aug 22). ARPANSA -

Introducing the National Diagnostic Reference Level Service (DRLS) [services]. Available:

http://www.arpansa.gov.au/services/ndrl/index.cfm

[126] K. Jessen, W. Panzer, P. Shrimpton, G. Bongartzm, J. Geleijns, S. Golding, et al., "EUR 16262:

European guidelines on quality criteria for computed tomography," Luxembourg: Office for

Official Publications of the European Communities, 2000.

[127] R. Bly, H. Jarvinen, A. Jahnen, H. Olerud, J. Vassileva, and S. Viogiatzi, "DDM2 Project Report

on European Population Dose Estimation," T. E. Commission, Ed., ed: European Commission,

2010.

[128] A. Wallace, A. Hayton, P. Thomas, and T. Beveridge, "The 2011–2013 National Diagnostic

Reference Level Service Report."

[129] B. für Strahlenschutz, "Bekanntmachung der aktualisierten diagnostischen Referenzwerte für

diagnostische und interventionelle Röntgenuntersuchungen," Salzgitter, Bfs, 2010.

[130] R. Treier, A. Aroua, F. Verdun, E. Samara, A. Stuessi, and P. R. Trueb, "Patient doses in CT

examinations in Switzerland: implementation of national diagnostic reference levels," Radiation

protection dosimetry, vol. 142, pp. 244-254, 2010.

[131] "Diagnostic Reference Levels Position Paper," ed. Ireland: The Medical Council, 2004, pp. 1-14.

[132] P. C. Shrimpton, M. C. Hillier, S. Meeson, and S. J. Golding, "Doses from Computed

Tomography (CT) Examinations in the UK- 2011 Review," C. a. E. H. Centre for Radiation, Ed.,

ed. London, England: Public Health England, 2014.

[133] M. Galanski, H. Nagel, and G. Stamm, "CT-Expositionspraxis in der Bundesrepublik

Deutschland," in RoFo-Fortschritte auf dem Gebiete der Rontgenstrahlen und der Neuen

Bildgebenden Verfahren, 2001, p. Rl.

[134] B. für Strahlenschutz, "Bekanntmachung der diagnostischen Referenzwerte für radiologische und

nuklearmedizinische Untersuchungen," Bundesanzeiger, vol. 143, pp. 17503-17504, 2003.

[135] J. E. Aldrich, A.-M. Bilawich, and J. R. Mayo, "Radiation doses to patients receiving computed

tomography examinations in British Columbia," Canadian Association of Radiologists Journal,

vol. 57, p. 79, 2006.

Page 189: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

168

[136] V. Tsapaki, J. E. Aldrich, R. Sharma, M. A. Staniszewska, A. Krisanachinda, M. Rehani, et al.,

"Dose Reduction in CT while Maintaining Diagnostic Confidence: Diagnostic Reference Levels

at Routine Head, Chest, and Abdominal CT—IAEA-coordinated Research Project 1," Radiology,

vol. 240, pp. 828-834, 2006.

[137] T. Easty and L. White, "Ontario Health Technology Assessment Committee (OHTAC) Computed

Tomography Dose Variability in Ontario," unpublished|.

[138] R. Smith-Bindman, J. Lipson, R. Marcus, K.-P. Kim, M. Mahesh, R. Gould, et al., "Radiation

dose associated with common computed tomography examinations and the associated lifetime

attributable risk of cancer," Archives of internal medicine, vol. 169, pp. 2078-2086, 2009.

[139] Y. Fukushima, Y. Tsushima, H. Takei, A. Taketomi-Takahashi, H. Otake, and K. Endo,

"Diagnostic reference level of computed tomography (CT) in Japan," Radiation protection

dosimetry, vol. 151, pp. 51-57, 2012.

[140] Japan Network of Research and Information on Medical Exposure, "Diagnostic Reference Levels

Based on Latest Surveys in Japan-Japan DRLs in 2015," ed. Japan: National institute of

Radiological Sciences, 2015.

[141] R. S. Livingstone and P. M. Dinakaran, "Radiation safety concerns and diagnostic reference

levels for computed tomography scanners in Tamil Nadu," Journal of medical

physics/Association of Medical Physicists of India, vol. 36, p. 40, 2011.

[142] A. Saravanakumar, K. Vaideki, K. Govindarajan, and S. Jayakumar, "Establishment of diagnostic

reference levels in computed tomography for select procedures in Pudhuchery, India," Journal of

medical physics/Association of Medical Physicists of India, vol. 39, p. 50, 2014.

[143] G. K. Korir, J. S. Wambani, I. K. Korir, M. A. Tries, and P. K. Boen, "NATIONAL

DIAGNOSTIC REFERENCE LEVEL INITIATIVE FOR COMPUTED TOMOGRAPHY

EXAMINATIONS IN KENYA," Radiation protection dosimetry, p. ncv020, 2015.

[144] J. Santos, S. Foley, G. Paulo, M. F. McEntee, and L. Rainford, "The establishment of computed

tomography diagnostic reference levels in Portugal," Radiation protection dosimetry, p. nct226,

2013.

[145] P. Teles, M. C. de Sousa, G. Paulo, J. Santos, A. Pascoal, G. Cardoso, et al., "Relatório sobre os

resultados do projecto Dose Datamed 2 Portugal," IST/ITN, 2012.

[146] N. P. Ghonge, "Computed tomography in the 21st century: current status & future prospects," J

Int Med Sci Acad (JIMSA), vol. 26, pp. 35-42, 2013.

Page 190: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

169

[147] A. Leotsakos, H. Zheng, R. Croteau, J. M. Loeb, H. Sherman, C. Hoffman, et al.,

"Standardization in patient safety: the WHO High 5s project," International journal for quality in

health care, vol. 26, pp. 109-116, 2014.

[148] E. S. Amis, P. F. Butler, K. E. Applegate, S. B. Birnbaum, L. F. Brateman, J. M. Hevezi, et al.,

"American College of Radiology white paper on radiation dose in medicine," Journal of the

american college of radiology, vol. 4, pp. 272-284, 2007.

[149] C. H. Cascos. (2015, Aug 28). Welcome to the Texas Administrative Code. Available:

http://www.sos.texas.gov/tac/index.shtml

[150] P. Kaye, "When do Ontario Acts and Regulations Come into Force?," Ontario2011.

[151] Ministry of Health and Long Term Care. (2007, Aug 27). Healing Arts Radiation Protection

(HARP) Commission Report - Ministry Reports - Publications - Public Information - MOHLTC.

Available: http://www.health.gov.on.ca/en/common/ministry/publications/reports/harp/harp.aspx

[152] R. M. Wachter, "The end of the beginning: patient safety five years after “To Err Is Human.”,"

Health Affairs, vol. 23, pp. 534-545, 2004.

[153] M. Q. Patton, "Two decades of developments in qualitative inquiry a personal, experiential

perspective," Qualitative Social Work, vol. 1, pp. 261-283, 2002.

[154] The Joint Department of Medical Imaging, "DI Appropriateness (DI-APP) Project Overview,"

unpublished|.

[155] C. Pope, P. van Royen, and R. Baker, "Qualitative Methods in Research on Healthcare Quality,"

Quality & Safety in Health Care, vol. 11, pp. 148-152, 2002.

[156] Committee 3 of the International Commission on Radiological Protection Protection. (Aug 26).

Diagnostic Reference Levels n Medical Imaging: Review and Additional Advice. Available:

http://www.icrp.org/docs/DRL_for_web.pdf

[157] M. Rehani, "Limitations of diagnostic reference level (DRL) and introduction of acceptable

quality dose (AQD)," The British journal of radiology, vol. 88, p. 20140344, 2014.

[158] J. M. Boone, K. J. Strauss, D. D. Cody, C. H. McCollough, M. F. McNitt-Gray, and T. L. Toth,

"Size-Specific Dose Estimates (SSDE) in Pediatric and Adult Body CT Examinations,"

Maryland2011.

[159] "Texas Radiation Control Act," in General Provisions and Standards for Protection Against

Machine-Produced Radiation vol. 289.231, ed. Texas, 2011, pp. 231-1 to 231-38.

Page 191: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

170

[160] "Accreditation Standards 2010: Diagnostic Imaging-Computed Tomography," Diagnostic

Accreditation Program of British Columbia, Vancouver2010.

[161] M. Fredriksson, P. Blomqvist, and U. Winblad, "Conflict and compliance in Swedish health care

governance: soft law in the ‘shadow of hierarchy’," Scandinavian Political Studies, vol. 35, pp.

48-70, 2012.

[162] Ministry of Health and Long Term Care, (2014, Apr.) "Quality-Based Procedures Indicators: An

Implementation Guidance Document," Government of Ontario, Available:

http://health.gov.on.ca/en/pro/programs/ecfa/docs/qbp_indicator_guidance_en.pdf

[163] "Bonn call-for-action: joint position statement by IAEA and WHO [Internet]. Geneva: World

Health Organization; 2013 [cited 2015 May 31]," ed.

[164] "Radiation Protection (Standards) Regulations, 1986," in L.N. 54/1986, ed. Kenya, 2012, pp. R2-

14 to R2-18.

Page 192: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

171

Appendix A: Sample Questions for Jurisdictional

Representatives

Sample questions to learn about the organization’s interest in CT radiation dose reduction

What sparked your jurisdiction’s interest in regulating CT radiation dose at each

healthcare institution?

o When did your organization first take notice of the radiation dose problem?

o What was the most alarming evidence that led your organization to start

formulation regulations?

Sample questions to understand the regulatory structure of the jurisdiction

How many organizations are involved in the regulation of radiation dose in your

jurisdiction? Describe the regulatory structure responsible for CT radiation dose

optimization.

o Which organizations are government funded? Which organizations are under

government control?

What is the connection between the different organizations that exist within the model?

o How often do they communicate with each other?

o Which organizations are directly influenced by one another?

o Describe the regulatory model within this jurisdiction.

Which organizations have legal authority in the regulation of radiation dose at the

institutional level?

o What is considered compliance by these organizations?

o What enforcement actions can these organizations take against non-compliance?

o How often do they check for compliance?

Sample questions to understand the decision-making process for jurisdictional approach

Why did you choose this approach?

o What was the evidence that supported your approach?

Sample questions to understand the effectiveness and response from the institutional

stakeholders

(If applicable) How has the regulations affected dose optimization in this jurisdiction?

o What has the measureable outcomes shown, in terms of dose optimization?

Page 193: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

172

What was the initial response of stakeholders at the institutions?

o Were you met with resistance?

o Were institutional stakeholders enthusiastic about these new regulations?

o Which parts of the model did the institutions agree with? Which parts met the

most resistance?

What is the attitude of stakeholders now?

o Are most institutions in compliance with your dose reduction model?

o Are institutions now taking their own initiative to optimize dose?

o Have you seen a positive response and uptake by institutions?

Sample Questions to identify gaps and potential solutions

What do you think is required for all institutions to comply with the “as low as reasonably

achievable” (ALARA) approach for all patient CT scans?

How can the current radiation protection system for CT be improved?

o For example, should there be a more rigorous compliance standard? Should

monitoring be performed by a committee or task force within the government? Is

more education required to understand the vastness of the issue?

What do you think is the biggest barrier to making the required improvements to the

system?

Page 194: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

173

Appendix B: Influence Diagrams of Each Jurisdiction’s CT Radiation Protection

Regulatory Structure

Australia Institutions

Australian Radiation Protection and Nuclear Safety Act 1998

To protect the health and safety of people, and to protect the environment, from the harmful effects

of radiationLast updated: March 14, 2012

Code of Practice for Radiation Protection in the Medical Applications of Ionizing

Radiation

Safety Guide for Radiation Protection

Diganostic and Interventional Radiology

State/ Territory Regulatory System (Interpretation of the ARPANSA Code)

Diagnostic Reference Levels

Radiation Health Committee

Radiation Health and Safety Council (Policy review council)

Australian Radiation Protection and Nuclear Safety Agency

Figure B- 1: The regulatory structure for radiation protection in medical applications for Australia. Similar to Canada, the licensing requirements are set by individual states.

Page 195: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

174

British Columbia Institutions

College of Physicians and Surgeons of British Columbia:

Diagnostic Accreditation Program (for accreditation)

Last updated: 2010

Health Canada Safety Code 35: Safety Procedures for the Installation, Use and Control of X-ray Equipment in Large Medical

Radiological Facilities

Last updated: 2008

Health Professions Act: Bylaws of the College of Physicians and

Surgeons Section B

Figure B- 2: A schematic to describe CT regulations in British Columbia. BC takes a unique approach that gives the College of Physicians and Surgeons of British Columbia legal

authority to accredit CT facilities

Page 196: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

175

California Institutions

Radiation Control Law Health and Safety Code, Division 104:

Environmental Health, Part 9: Radiation, Chapter 8

Last updated: September 2012

Joint Commission:Diagnostic Imaging Standards

Last updated: July 1, 2015

Intersocietal Accreditation Commission:Standards and Guidelines for CT

Accreditation

Last updated: August 3, 2015

American College of Radiology:CT Accreditation Program

Last updated: July 27, 2015

State Department of Health Services (For licensing, and adverse events

reporting)

Last updated: July 1, 2015

Figure B- 3: The regulatory structure for CT radiation protection in California. The dashed lines suggest that accreditation by only one of the three listed programs is required.

Page 197: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

176

Germany Institutions

Radiation Protection OrdinanceOn the protection against damage and injuries

caused by ionizing radiation Last updated: December 2014

Federal Ministry for Environment and Nuclear Safety

(Responsible for lawmaking)

Federal Office for Radiation Protection

(Scientific consultants of the Ministry, establishes DRLs, reviews scientific

research)

German Commission on Radiological Protection

(consists of different working groups that consult with the Ministry)

German State Offices(Has to approve and

interpret new regulations)

Local Medical Authorities (Inspects for compliance)

Council Directive 97/43/EURATOM On health protection of individuals

against the dangers of ionizing radiation in relation to medical exposure

Published: June 30, 1997

Effective: May 13, 2000

Council Directive 2013/59/EURATOM Laying down basic safety standards for protection against the dangers arising

from exposure to ionizing radiation (Repealing Directive 97/43/EURATOM)

Published: December 5, 2013

Effective: February 6, 2018

Figure B- 4: The regulatory structure for CT radiation protection in Germany. The local medical authorities are appointed to oversee the compliance of CT facilities. However,

they are accountable to the state offices that are trusted with the implementation of the federal regulations.

Page 198: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

177

India Institutions

Atomic Energy (Radiation Protection) RulesGazette of India, Part II, Section 3,

Sub-section (i)

Published: August 25, 2004

Atomic Energy Regulatory Board Computed Tomography Licensing

Figure B- 5: India's regulatory structure for CT operation is very simple, and only involves the licensing of CT facilities. The licensing process is free to reduce chances of

corruption.

Page 199: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

178

Ireland Institutions

Medical Council Diagnostic Reference Levels

Position Paper Published: September 3, 2004

Medical Council (For audits, and DRL

updates)- Unsuccessful

Ireland Institutions

European Communities (Medical Ionizing Radiation Protection)

RegulationsS.I. 478/2002

Published: October 15, 2002

European Communities (Medical Ionizing Radiation Protection)

RegulationsS.I. 478/2002

Published: October 15, 2002

National Radiation Safety Committee

(For DRL monitoring and updates)Established: November 2007

Medical Exposures Radiation Unit

(For audits, legislation compliance etc.)

Health Services Executive

Council Directive 97/43/EURATOM On health protection of individuals

against the dangers of ionizing radiation in relation to medical exposure

Published: June 30, 1997

Effective: May 13, 2000

Council Directive 97/43/EURATOM On health protection of individuals

against the dangers of ionizing radiation in relation to medical exposure

Published: June 30, 1997

Effective: May 13, 2000

Council Directive 2013/59/EURATOM Laying down basic safety standards for protection against the dangers arising

from exposure to ionizing radiation (Repealing Directive 97/43/EURATOM)

Published: December 5, 2013

Effective: February 6, 2018

Council Directive 2013/59/EURATOM Laying down basic safety standards for protection against the dangers arising

from exposure to ionizing radiation (Repealing Directive 97/43/EURATOM)

Published: December 5, 2013

Effective: February 6, 2018

(a) (b)

Figure B- 6: The intended regulatory structure for CT radiation protection in Ireland. The limited available financial and human resources resulted in the inability of the Medical

Council to oversee compliance with S.I. 478/2002. (b) The current regulatory structure in Ireland as the responsibilities to ensure compliance with the CT standards are entrusted

to a branch of the Health Services Executive.

Page 200: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

179

Japan Institutions

Japan Network of Research and Information on Medial Exposure (For DRL monitoring and updates)

First DRLs Published: June, 2015

National Institute of Radiological Sciences

Medical Exposure Research Project

Figure B- 7: Japan interestingly does not have any regulations designed to oversee operation of CT. However, the Japan Network of Research and Information on Medical

Exposure and other associated organizations have realized the increasing risks associated with high doses in CT exams. This has led to the proposal of DRLs.

Page 201: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

180

Kenya Institutions

Radiation Protection (Standards) Regulations

[L.N. 54/1986] Effective: 1986

Radiation Protection (Safety) Regulations

[L.N. 160/2010] Effective: 2010

National Council for Law Radiation Protection Act

[L.N. 171/1984]Effective: November 1, 1984

Radiation Protection Board Safety Assessments of the

Radiation Facilities & QC for X-ray Machines

AFROSAFE (For DRLs establishment)

Figure B- 8: Kenya's regulatory structure is simplistic. However, facilities do require licensing to operate CT scanners and there are periodic safety assessments of the CT

scanners. The assessment are focused on the technical functionality of the CT scanners. More interestingly is, perhaps, the Afrosafe initiative that was established to fulfill World

Health Organization’s Bonn-Call for Action.

Page 202: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

181

Ontario Institutions

Healing Arts Radiation Protection Act (HARP Act)

R.S.O. 1990, c. H.2

Last updated: May 12, 2011

Healing Arts Radiation Protection Regulations

(HARP Regulations)R.R.O. 1990, Reg. 543

Last updated: May 12, 2011

Ministry of Health and Long Term CareX-ray Inspection Service (for registration

and inspections)

Last updated: August 3, 2015

Figure B- 9: Ontario's regulatory structure is only applicable to the technical standards for CT scanners. The HARP Act and Regulations pertain to the technical functionality of

operational CT scanners in Ontario.

Page 203: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

182

Portugal Private Institutions

Portugal Public Institutions

Portugal Decree Law No. 180/2002For health protection of individuals against the

dangers of ionizing radiation in medical exposure

National Technological Institute (Responsible for activities of

radiation protection)Ministry of Health

National Commission of Protection against Radiation

(unsure of purpose)

Directorate-General Health

Regional Health Administrations(Works with national organizations

to license, and audit)

Portugal Decree Law No. 492/1999 (Amended as Decree Law 240/2000)

Approves the legal licensing and supervision regime for private health facilities with diagnostic and/or therapeutic ionizing radiation sources, ultrasound,

or magnetic fields

National Technical Commission (sets licensing rules)

Technical Verification Commission (Works with Regional Health

Administrations to survey and inspect)

Regional Health Administrations

Council Directive 97/43/EURATOM On health protection of individuals

against the dangers of ionizing radiation in relation to medical exposure

Published: June 30, 1997

Effective: May 13, 2000

Council Directive 2013/59/EURATOM Laying down basic safety standards for protection against the dangers arising

from exposure to ionizing radiation (Repealing Directive 97/43/EURATOM)

Published: December 5, 2013

Effective: February 6, 2018

Figure B- 10: Portugal interestingly has more rigorous standards for private institutions. Public institutions are simply expected to obtain a license at installation and it is

assumed compliance with the standards is continuous. Private institutions, however, are subjected to additional inspections and are regulated by an additional regulation.

Page 204: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

183

Switzerland Institutions

The Federal Assembly of the Swiss Confederation

Radiological Protection Act Section 814.50

Last updated: January 1, 2007

The Swiss Federal CouncilRadiological Protection Ordinance

Section 814.501Last updated: January 1, 2014

Federal Office of Public Health(For licensing, inspections, and DRLs

monitoring and updates)

Council Directive 97/43/EURATOM On health protection of individuals

against the dangers of ionizing radiation in relation to medical exposure

Published: June 30, 1997

Effective: May 13, 2000

Council Directive 2013/59/EURATOM Laying down basic safety standards for protection against the dangers arising

from exposure to ionizing radiation (Repealing Directive 97/43/EURATOM)

Published: December 5, 2013

Effective: February 6, 2018

Figure B- 11: Switzerland has a very centralized regulatory structure for CT radiation protection. The Federal Office of Public Health is responsible for oversight of CT facilities

and establishment of DRLs.

Page 205: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

184

Texas Institutions

Texas Radiation Control ActHealth and Safety Code, Title 5: Sanitation and

Environmental Quality, Subtitle D: Nuclear and Radioactive Materials, Chapter 401: Radioactive Materials and Other

Sources of Radiation Effective: September 1, 1991

Texas Department of State Health Services

Radiation Control Program

Inspections Branch

Texas Administrative Code Section 289

Licensing GroupPolicy/Standards & Quality Assurance

(Rulemaking)

Figure B- 12: The Texan regulatory structure for CT radiation protection involves three sub-branches. The inspections branch oversees compliance of the CT facilities, the

licensing group grants the initial licenses and adjusts the licensing based on inspection results, and the policy/standards and quality assurance groups reviews the notes from

inspections and follows up with the registrants and is responsible for rulemaking.

Page 206: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

185

England Institutions

Scotland Institutions

Wales Institutions

Health and SafetyIonizing Radiations Regulations 1999

1999 No. 3232Effective: January 1, 2000

Health and Safety Ionizing Radiation (Medical Exposure)

Regulations 20002000 No. 1059

Effective: May 13, 2000

Department of Health Public Health England

(Consultants to the governmental organization)

National Radiation Protection Board (DRL updates, and other scientific

research)

Care Quality Commission (Compliance checks,

licensing, etc.)

Scottish General Inspectors with help from

NRPB (Compliance checks,

licensing, etc.)

Welsh General Inspectors with help from

NRPB (Compliance checks,

licensing, etc.)

Medical Products Healthcare Regulatory Agency

(Checks compliance with technical aspects)

Council Directive 97/43/EURATOM On health protection of individuals

against the dangers of ionizing radiation in relation to medical exposure

Published: June 30, 1997

Effective: May 13, 2000

Council Directive 2013/59/EURATOM Laying down basic safety standards for protection against the dangers arising

from exposure to ionizing radiation (Repealing Directive 97/43/EURATOM)

Published: December 5, 2013

Effective: February 6, 2018

Figure B- 13: The United Kingdom regulatory structure is applicable to institutions from England, Scotland and Wales. The regulations are centralized in these three regions, but

the inspection authorities vary

.

Page 207: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

186

Appendix C: Bonn Call-for-Action

The following is a copy of the original statement from the World Health Organization and IAEA that

explains the Bonn Call-for-Action, and can be found here:

http://www.who.int/ionizing_radiation/medical_exposure/Bonn_call_action.pdf [163]

Afrosafe modelled their organization to fulfill the requirements of the Bonn Call-for-Action.

Introduction

The International Atomic Energy Agency (IAEA) held the “International Conference on Radiation

Protection in Medicine: Setting the Scene for the Next Decade” in Bonn, Germany, in December 2012,

with the specific purpose of identifying and addressing issues arising in radiation protection in medicine.

The conference was co-sponsored by the World Health Organization (WHO), hosted by the Government

of Germany through the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety,

and attended by 536 participants and observers from 77 countries and 16 organizations. An important

outcome of the conference was the identification of responsibilities and a proposal for priorities for

stakeholders regarding radiation protection in medicine for the next decade. This specific outcome is the

Bonn Call-for-Action.

There is no doubt that the application of ionizing radiation and radioactive materials in diagnostic,

interventional and therapeutic procedures in medicine is beneficial for hundreds of millions of people

each year. However, employing radiation in medicine has to involve a careful balance between the

benefits of enhancing human health and welfare, and the risks related to the radiation exposure of people.

There is a need for a holistic approach which includes partnership of national governments, civil society,

international agencies, researchers, educators, institutions and professional associations aiming at

identifying, advocating and implementing solutions to address existing and emerging challenges; and

leadership, harmonization and co-ordination of activities and procedures at an international level.

The aims of the Bonn Call-for-Action are to a) strengthen the radiation protection of patients and health

workers overall; b) attain the highest benefit with the least possible risk to all patients by the safe and

appropriate use of ionizing radiation in medicine; c) aid the full integration of radiation protection into

health care systems; d) help improve the benefit/risk-dialogue with patients and the public; and e)

enhance the safety and quality of radiological procedures in medicine.

The Bonn Call-for-Action highlights ten main actions, and related sub-actions, that were identified as

being essential for the strengthening of radiation protection in medicine over the next decade. The actions

are not listed in order of importance. Action by all stakeholders is encouraged.

Action 1: Enhance the implementation of the principle of justification

a) Introduce and apply the 3A’s (awareness, appropriateness and audit), which are seen as tools

that are likely to facilitate and enhance justification in practice;

b) Develop harmonized evidence-based criteria to strengthen the appropriateness of clinical

imaging, including diagnostic nuclear medicine and non-ionizing radiation procedures, and

involve all stakeholders in this development;

Page 208: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

187

c) Implement clinical imaging referral guidelines globally, keeping local and regional variations

in mind, and ensure regular updating, sustainability and availability of these guidelines;

d) Strengthen the application of clinical audit in relation to justification, ensuring that justification

becomes an effective, transparent and accountable part of normal radiological practice;

e) Introduce information technology solutions, such as decision support tools in clinical imaging,

and ensure that these are available and freely accessible at the point-of-care;

f) Further develop criteria for justification of health screening programmes for asymptomatic

populations (e.g. mammography screening) and for medical imaging of asymptomatic individuals

who are not participating in approved health screening programmes (e.g. use of CT for individual

health surveillance).

Action 2: Enhance the implementation of the principle of optimization of protection and safety

a) Ensure establishment, use of, and regular update of diagnostic reference levels for radiological

procedures, including interventional procedures, in particular for children;

b) Strengthen the establishment of quality assurance programmes for medical exposures, as part

of the application of comprehensive quality management systems;

c) Implement harmonized criteria for release of patients after radionuclide therapy, and develop

further detailed guidance as necessary;

d) Develop and apply technological solutions for patient exposure records, harmonize the dose

data formats provided by imaging equipment, and increase utilization of electronic health records.

Action 3: Strengthen manufacturers’ role in contributing to the overall safety regime

a) Ensure improved safety of medical devices by enhancing the radiation protection features in

the design of both physical equipment and software and to make these available as default

features rather than optional extra features;

b) Support development of technical solutions for reduction of radiation exposure of patients,

while maintaining clinical outcome, as well as of health workers;

c) Enhance the provision of tools and support in order to give training for users that is specific to

the particular medical devices, taking into account radiation protection and safety aspects;

d) Reinforce the conformance to applicable standards of equipment with regard to performance,

safety and dose parameters;

e) Address the special needs of health care settings with limited infrastructure, such as

sustainability and performance of equipment, whether new or refurbished;

f) Strengthen cooperation and communication between manufacturers and other stakeholders,

such as health professionals and professional societies;

g) Support usage of platforms for interaction between manufacturers and health and radiation

regulatory authorities and their representative organizations.

Action 5: Shape and promote a strategic research agenda for radiation protection in medicine

a) Explore the re-balancing of radiation research budgets in recognition of the fact that an

overwhelming percentage of human exposure to man-made sources is medical;

Page 209: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

188

b) Strengthen investigations in low-dose health effects and radiological risks from external and

internal exposures, especially in children and pregnant women, with an aim to reduce

uncertainties in risk estimates at low doses;

c) Study the occurrence of and mechanisms for individual differences in radiosensitivity and

hyper-sensitivity to ionizing radiation, and their potential impact on the radiation protection

system and practices;

d) Explore the possibilities of identifying biological markers specific to ionizing radiation;

e) Advance research in specialized areas of radiation effects, such as characterization of

deterministic health effects, cardiovascular effects, and post-accident treatment of overexposed

individuals;

f) Promote research to improve methods for organ dose assessment, including patient dosimetry

when using unsealed radioactive sources, as well as external beam small-field dosimetry.

Action 6: Increase availability of improved global information on medical exposures and

occupational exposures in medicine

a) Improve collection of dose data and trends on medical exposures globally, and especially in

low- and middle-income countries, by fostering international co-operation;

b) Improve data collection on occupational exposures in medicine globally, also focussing on

corresponding radiation protection measures taken in practice;

c) Make the data available as a tool for quality management and for trend analysis, decision

making and resource allocation.

Action 7: Improve prevention of medical radiation incidents and accidents

a) Implement and support voluntary educational safety reporting systems for the purpose of

learning from the return of experience of safety related events in medical uses of radiation;

b) Harmonize taxonomy in relation to medical radiation incidents and accidents, as well as related

communication tools such as severity scales, and consider harmonization with safety taxonomy in

other medical areas;

c) Work towards inclusion of all modalities of medical usage of ionizing radiation in voluntary

safety reporting, with an emphasis on brachytherapy, interventional radiology, and therapeutic

nuclear medicine in addition to external beam radiotherapy;

d) Implement prospective risk analysis methods to enhance safety in clinical practice;

e) Ensure prioritization of independent verification of safety at critical steps, as an essential

component of safety measures in medical uses of radiation.

Action 8: Strengthen radiation safety culture in health care

a) Establish patient safety as a strategic priority in medical uses of ionizing radiation, and

recognize leadership as a critical element of strengthening radiation safety culture;

b) Foster closer co-operation between radiation regulatory authorities, health authorities and

professional societies;

Page 210: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

189

c) Foster closer co-operation on radiation protection between different disciplines of medical

radiation applications as well as between different areas of radiation protection overall, including

professional societies and patient associations;

d) Learn about best practices for instilling a safety culture from other areas, such as the nuclear

power industry and the aviation industry;

e) Support integration of radiation protection aspects in health technology assessment;

f) Work towards recognition of medical physics as an independent profession in health care, with

radiation protection responsibilities; g) Enhance information exchange among peers on radiation

protection and safety-related issues, utilizing advances in information technology.

Action 9: Foster an improved radiation benefit-risk-dialogue

a) Increase awareness about radiation benefits and risks among health professionals, patients and

the public;

b) Support improvement of risk communication skills of health care providers and radiation

protection professionals – involve both technical and communication experts, in collaboration

with patient associations, in a concerted action to develop clear messages tailored to specific

target groups;

c) Work towards an active informed decision making process for patients.

Action 10: Strengthen the implementation of safety requirements globally

a) Develop practical guidance to provide for the implementation of the International Basic Safety Standards in health care globally;

b) Further the establishment of sufficient legislative and administrative framework for the

protection of patients, workers and the public at national level, including enforcing requirements

for radiation protection education and training of health professionals, and performing on-site

inspections to identify deficits in the application of the requirements of this framework

Page 211: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

190

Appendix D: RACT 1

Domain 0 1 2 3 4

Executability

Details are provided

to allow intended

audience to perform

the recommended

actions in the

specified

circumstances

There are no

recommended

action plans for

specified hazardous

circumstance

(e.g. no

requirement of

DRLs, excessive

dose is not defined)

Action plan is

vague and

ambiguous; The

plan can be

interpreted in many

ways; The

legislative body

should provide

additional

guidelines to make

specifications easily

achievable

Clarification is

likely required

from the

legislative body to

follow

recommended

action plan

Recommended

actions can be

achieved with

little guidance

from the

authoritative

body

Recommended actions are unambiguous and

recommendation can easily be interpreted and

followed without guidance from the legislative

body

(e.g. DRLs are defined by jurisdiction and

management options for exceedance are detailed

OR local DRLs are required to be established

using specified method such as phantoms,

frequency of updates and reporting is specified )

Comprehensiveness

Management options

are provided for a

range of specified

conditions

Assumes only one

possible operation

condition

(e.g. DRLs are not

discussed)

Few operation

conditions are

discussed

Some operation

conditions are

discussed

Most operation

conditions are

discussed

Accounts for all possible conditions based on

current knowledge

(e.g. DRLs are developed for pediatric

populations and adult populations for all routine

scans)

Rigor

A combination of

evidence that must be

produced to achieve

compliance and the

harshness of

penalties for

violations

No burden of

evidence is required

by the authoritative

body;

(e.g. DRLs are not

required to be

established at a

local, state or

national level, dose

levels are not

monitored)

Burden of evidence

is minimal;

Violations have

weak penalties, if

any

Some evidence is

required;

Penalties are

moderate to

severe

Reasonably high

amounts of

evidence is

required, but

additional

evidence may be

acquired;

Penalties are

severe

Maximum amount of evidence is required to

ensure intent of regulation is achieved;

Violations will result in loss of operation

privileges

(e.g. DRLs are updated periodically in

accordance with the compilation of dose data

from all institution, constant exceedance of

DRLs will result in loss of CT operation, dose

data is collected annually for compilation,

DRLs are benchmarked against other

jurisdictions)

Figure D- 1: RACT 1 is simplistic in its design and contains only three domains that were thought to encompass all the important attributes of radiation protection document

quality

Page 212: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

191

(a)

Ontario BC California Texas Ireland Germany E C R E C R E C R E C R E C R E C R

Technical Requirements

Operation Requirements

Radiation Safety Committee/QA Implementation

Radiation Dose Reporting

Diagnostic Reference Levels

(b)

Technical Reqs Operation Reqs Radiation Safety Committee/QA Implementation

Radiation Dose Reporting

Diagnostic Reference Levels

E C R E C R E C R E C R E C R

Ontario 1 3 1 1 0 1

BC 3 4 3 3 4 4

California 2 4 3 3 4 4

Texas 2 4 3 3 2 2

Ireland 1 3 2 2 3 2

Germany 1 2 2 2 3 2

Figure D- 2: Sample rater worksheets for the reviewers to record the score of each domain and theme for every jurisdiction. E represents executability; C is comprehensiveness; R

is rigor

Page 213: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

192

Appendix E: RACT 2

Part 1: Comprehensiveness Assessment

A regulatory model for medical radiation exposure includes many different publications by various

responsible authorities to enforce and support dose optimization efforts. Legally binding legislation,

accreditation standards, and clinical guidelines are some of the most common types of documents that are

used to address radiation protection. These documents ideally work together to effectively and

comprehensively address the important elements of radiation protection. A comprehensive regulatory

model provides management options for a range of conditions, and can address both legal and clinical

situations that may arise in medical exposure radiation protection.

Theme Selection

Each jurisdictional model may use a different organizational structure, different methods, and different

terminologies to address the various elements. However, every model consistently addresses similar

circumstances, which are denoted as “themes” in this checklist, in its attempt to regulate and enforce

medical exposure radiation protection. The following key items therefore represent the recurring elements

that were included in each jurisdictional model. These elements were then developed, and grouped

together into overarching constructs to form important “sub-themes” within the general “themes” that are

important for medical exposure radiation protection.

How to Use

This comprehensiveness assessment is designed as a quantitative evaluation for each regulatory model,

and should be used as a binary checklist. Each document should have its own assessment checklist.

Regardless of the quality of the fulfillment of each item, the rater is simply asked to identify whether or

not the key item was included in the document being reviewed. The quality evaluation will come in the

subsequent parts in this framework.

Inter-rater Reliability

Due to the use of quantitative measures, the inter-rater reliability is expected to be 1.00 since the checklist

of items was designed to not be subject to interpretation. However, if there is discrepancy, the inter-rater

reliability should be calculated for each theme and the aggregated sum using percentage agreement,

which is simply the number of times the raters agree divided by the sum of items [121]. Inter-rater

reliability should be calculated for each theme, as well as for the aggregated sum. If the inter-rater

reliability is below 90%, a discussion should be held to propose clarifications on the areas of confusion

[121]. Final scores for each theme should be proposed through discussion and consensus once inter-rater

reliability is satisfactory to facilitate subsequent analysis. The total number of key items that have been

Page 214: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

193

fulfilled for each theme should be summed to provide an indication of the comprehensiveness of each

document. The percentage fulfillment should be calculated per theme, and overall:

% 𝐹𝑢𝑙𝑓𝑖𝑙𝑙𝑚𝑒𝑛𝑡 = 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑖𝑡𝑒𝑚𝑠 𝑓𝑢𝑙𝑓𝑖𝑙𝑙𝑒𝑑

𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑖𝑡𝑒𝑚𝑠 (F-1)

Comprehensiveness Checklist

General Provisions

Purpose of the document

Scope of the document (i.e. the range of circumstances, range of population types, range of

geographical coverage)

Explains structure of the document

Scope of “medical exposure”

Inclusion of relevant definitions (e.g. dose constraint, clinical audit, quality assurance, quality control

etc.)

The professional agencies and organizations that contributed to the document’s content

Date that document becomes effective

Responsible Authority

The Highest Responsible Authority

This is the authority who

authorized the document and its

content

Responsible authority is specified

Responsibilities and duties (e.g. impose requirements, review

related standards, update regulations)

Organizational structure

Procedure to delegate members

Delegation of responsibilities to sub-authorities to fulfill

requirements (e.g. accreditation organizations, inspection

agencies)

Authority and powers (e.g. permissible actions during

emergencies, legal power for sanctions)

Legal protection (i.e. protect individuals from personal liability)

Remuneration of any employee in any responsible authority's

council or sub-councils

Recordkeeping requirements (e.g. format of reports, timeframe

for keeping records)

Dissemination of information

Expected results (e.g. production of safety guidelines)

Advisory bodies/organizations or experts are consulted (i.e.

consultation with medical societies in the design of the

regulations)

Supervisory Authority

The departmental branch that is

delegated by the highest

responsible authority to monitor

compliance with the document

Supervisory authority is specified

Responsibilities and duties (e.g. performs clinical audits, reviews

radiation incident reports, recommend corrective actions)

Authority and powers

Recordkeeping requirements

Organizational structure

Procedure to delegate members (including consultants)

Remuneration of each member

Recordkeeping requirements for each institution (e.g. personnel

qualifications, inspection results)

Page 215: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

194

Other Sub-councils for Radiation

Health and Safety

Some responsible authorities

require the formation of sub-

councils that advise the responsible

authority on issues concerning

radiation health and safety

Name of the required sub-councils

Functions (i.e. purpose and scope)

Organizational structure

Delegation of members

Length of each member’s appointment

Authority and powers

Responsibilities and duties

Expected results (e.g. periodic meetings, consultation with

responsible authority)

Financial Matters The account/fund program is specified

Usage of the fees or revenues from the program

Division of monetary fines from institutions

Rules associated with the account/fund

Accessibility and Communication

of Information

Terms and conditions for the possibility of collaboration with

external organizations, other sub-councils or other governments

Accountability for operations of all participating organizational

bodies (e.g. quarterly reports, meetings with the responsible

authority)

Information is readily available to relevant stakeholders and the

general public regarding the regulation of radiation sources

Process for general public to request information for any facility

Secure process for participating organizational bodies to

communicate confidential information

Licensing and Accreditation

Basic Licensing Standards Responsible “licensing authority” is specified

Mandatory accreditation by listed authorities

Frequency of mandatory accreditation

Authority and powers granted to the “licensing authority

Types of activities that require licensing, registration and/or

accreditation

A schedule of fees is available to apply, modify or transfer a

license

Application Process Criteria for application (e.g. reliable applicant, financial security,

qualifications of applicant)

Risk assessment to be performed by applicant

Documents required for application (e.g. facility plan)

Time frame for acquiring a license before an installation

Registry to identify all qualified applicants are kept for a

specified period

Investigation of the applicant’s qualifications by the licensing

authority during the application process

Application documents are made available for public inspection

upon request

Frequency of licensing periods

Decision-making procedure of

licensing authority

Criteria to grant or deny a license

Process to explain the refusal or revoking of a license

Surveys of the facility are conducted by licensing authority

Conditions for the approval of a license

Appeal of licensing decisions Description of how to request an appeal

Page 216: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

195

Time frame for appealing a licensing decision

The appeal process (e.g. court hearings, witnesses, evidence

presented)

Modification, transfer, revoking or

suspension of a license

Situations that require the modification, revoking or suspension

of a license

Information that must be provided to request modification (e.g.

modified facility plan, reason for modification)

License violations are brought to the attention of the holder

before a final decision is made, except in cases where

occupational and public health or safety are compromised

Process to inhibit application by a license holder who has had a

revoked license

Process to transfer a license (e.g. procedure to transfer

confidential information if a license holder is retiring)

Miscellaneous

Other provisions that relate to

licensing

License format and information to be included (e.g. period of

validity, date of expiration, licensee name)

Required actions for a device that is no longer licensed (i.e.

decommissioning a device)

Description of the process to change fees

Technical Requirements

New installation

Criteria that should be considered by license holder before

undertaking a new radiological installation

Recommendations (by different reputable organizations) for

relevant reports and guidance documents that should be

consulted before selection of equipment

Records of receipt of radiation machines

Specifications for acceptable CT machines in facilities

Procedure for approval or acceptance testing

In addition to the license holder duties, there are requirements

for the persons who assemble or install the new machine (e.g.

records for the new installation, notification of licensing

authority)

Baseline measures of radiation output and other CT metrics

using a CT phantom (full acceptance testing)

Consultation of a qualified expert (e.g. radiation protection

officer, medical physicist)

Maintenance and Repairs Preventative maintenance program requirements

Radiation output and their CT metrics using phantoms is

measured as a part of maintenance programs

Results of the maintenance testing should be reviewed by a

qualified person periodically

The operation of the equipment is re-assessed following any

repair, maintenance or modification on radiation producing

equipment

The operation of the equipment is re-calibrated following any

repair, maintenance or modification on radiation producing

equipment

Recommendations for calibration procedure

When a fault with an equipment is found to compromise patient

safety, process description for reporting of fault internally

Page 217: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

196

When a fault with an equipment is found to compromise patient

safety, process description for reporting of fault to responsible

authority

Time frame to establish a plan of action for repair

Exposure rates outside the examination area from scattering or

leakage are kept as low as reasonably achievable

Quality Control Testing Recommended procedure for quality control testing

Frequency of each quality control test

Revision and investigation procedure for out of range or

unacceptable quality control values by license holder or

designated responsible personnel

Corrective actions are taken by license holder when quality

control tests are unsatisfactory

Description of unsatisfactory CT control tests

Calibration equipment Regular monitoring of equipment used to generate diagnostic

findings (e.g. calibration equipment)

Recordkeeping requirements An inventory list summarizing technical specifications of

equipment maintained and available for inspection by the

responsible authority

Information required on the records for any work that was

performed on the equipment

Period required to maintain records

Records for transfer or disposal of machine

Record of images acquired for quality control testing is kept for

inspection by agency

Consultation and Communication

Standards

Technical assessments are performed or supervised by a

qualified expert (e.g. medical physicist)

Consultation or communication procedure between the qualified

technical expert (e.g. medical physicist) and the clinical experts

(e.g. practitioner, medical director)

Communication requirement between the license holders of

different machines

Facility Requirements

Specified areas

(e.g. supervised area, controlled

area, uncontrolled area)

Definition of the area (e.g. maximum threshold for radiation

exposure in the area)

Criteria for admittance (e.g. workers only, patients undergoing

treatment)

Procedure for admittance of pregnant women

Instructions are provided before entering specified area for the

first time

Monitoring of areas (e.g. local air radiation exposure rates)

Workers must review instructions for admittance periodically

Records are kept to note who have received the instructions

Facility layout

Facility layout (continued)

Technical requirements for rooms containing irradiation

equipment (e.g. suitable patient monitoring equipment,

emergency switches, windows)

Shielding requirements

Shielding design must be performed under the consultation of a

qualified technical expert

Shielding plans are reviewed by a third party expert

Page 218: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

197

Standard format of warning notices

Placement of warning notices

Instructions for siting, and construction of the facilities with

irradiation equipment (e.g. examination areas, interpretation

areas)

Signs that show accountability, and the license of each facility is

visually available

Price list of imaging procedures available upon request

Operational Requirements

Inspection by supervisory authority

Expected inspection of the facility by the supervisory authority

Remote inspections may be performed by supervisory authority

Authority of inspector

Supervisory authority’s process to appoint inspectors

Pre-requisite qualifications for the inspector role

Training program content and continuing education

requirements for the inspector role

Supervisory authority has a gradual proficiency level system for

its inspectors that lists the area of responsibility for each

inspector

Responsibilities and duties of inspector

Instructions to inspect operational procedures that the inspector

must follow

Average inspection frequency for each irradiation machine type

Procedures for the inspector to report and notify the supervisory

authority and license holder of non-compliance

Procedure to obtain warrants in normal situation when non-

compliance is suspected and a more detailed search is required

The approval of the warrants are monitored and the supervisory

authority's procedure to issue a warrant is described

Rights and duties of the license holder during and after

inspections

Procedure for the license holder to follow in cases of non-

compliance

Accountability requirements for license holders who must take

corrective actions in cases of non-compliance

Internal clinical audits Requirement for internal audits by the license holder and/or

internal radiation protection committee1

Recordkeeping requirements for internal clinical audit results

Audits are performed by qualified experts

An internal safety committee is established with regular

meetings and regular documentation

Frequency of internal clinical audit

Clinical justification for medical

radiation exposure

Requirement to justify the radiation exposure

Justification is performed by a qualified radiologist

Potential benefits and detriments are compared

Alternative modalities are considered

Referral process Referrals should not be made by referring physician unless a net

benefit to the intended exposure is demonstrated

Recommendations to referral guidelines are available

Page 219: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

198

Requirement to have a standard format for written referrals

Recommendation on how to address incorrect referrals

“As low as reasonably achievable”

(ALARA) approach to radiation

exposure

Procedure is in place to ask patient whether they have previously

undergone medical applications; information is drawn from

previous scans whenever possible

Radiation exposure is minimized by taking into account the

equipment and circumstances of each individual case (i.e. dose

reduction techniques or devices like body part shield must be

used)

The optimization process includes the balancing of image

quality and the purpose of the image acquisition

Recommendations to review research evidence by relevant to

stakeholders that improve safety of healthcare systems and

people’s health standards

Preventative measures are taken to avoid exposures greater than

intended from equipment failure

Operating and safety procedures (e.g. control of scattered

radiation, film processing procedures) are available to the

persons working in the radiation area

A record shows that persons working in the area read the

operating and safety procedures at a specified frequency

Findings of inspection programmes and main findings are

available to public

Standard clinical protocols for

routine scans

Standard protocols for routine scans are available (i.e. written in

a binder, or digitized)

Clinical protocols are periodically reviewed and updated

internally at the institution by radiologists, medical director

and/or radiation protection committee

Clinical protocols are optimized with the consultation of the

qualified technical expert

Clinical protocols are periodically reviewed by the supervisory

authority

A clear criteria defining adult and paediatric scans

Specific procedure to follow for health screenings using CT

Delivery of ionizing radiation Procedure for conducting radiation exposure in emergency

clinical situations (e.g. trauma situations)

Procedure to ensure that the correct patient is irradiated

Procedure to obtain informed consent from the patient

Guidelines for the operator on the delivery of medical radiation

Scans with unusually high doses or high risks must be performed

under the responsibility of an authorized person with additional

training

Portable and mobile radiological equipment are only used in

extenuating circumstances (e.g. unsafe medically to transfer

patient to a stationary radiological installation)

Images are reviewed for diagnostic quality before patient leaves

the facility

Recordkeeping requirements to show the use of each radiation

machine (e.g. who the operator was during a specified time

period)

Page 220: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

199

Any tests and activity of health facilities must be shared with

insurance companies

Special populations

Special populations (continued)

Procedure to determine if a women of childbearing age may be

pregnant or breastfeeding

Procedure to scan a pregnant woman with minimal radiation

exposure when scanning cannot be avoided

Special attention for paediatric procedures

Systems to file complaints A complaint system is available for patients at the institution

The institutional complaint system cannot be distorted

Accountability requirements for institutional complaint systems

(e.g. reports sent to supervisory authority)

Procedure for workers to notify supervisory authority of unsafe

radiation situations

Assurance that workers will not be reprimanded for filing

complaints or notices to the supervisory authority

Procedure that the supervisory authority follows in cases of

complaints by patients or workers

Delegation of Medical Acts Procedure description for the delegation of medical acts by

persons other than physicians to ensure patient safety and quality

Recordkeeping requirements for delegated medical acts

Additional training requirements for non-physicians performing

delegated medical acts

“New” Procedures Procedure in place for experts to review and approve “new”

practices including medical radiation

Exemptions to the use of approved practices (e.g. in emergency

situations, new procedures may be used at the discretion of

medical practitioner)

Miscellaneous

Requirements for internal

regulations, emergency situations

and accountability for

communication standards

Requirement to prepare plans for emergency situations

Criteria to establish internal (i.e. institutional level) rules and

regulations

Content that should be included in the internal rules and

regulations--Including written procedures for operational

workflows

Electronic communication methods may be used to notify or

communicate with the supervisory authority

Personnel Requirements

This section describes the qualified professionals who are required to be present and/or consulting at

the institutional level.

Administrative Responsible Person

This is the person who is legally

liable for a given radiological

action (e.g. employer, license

holder, owner)

Responsibilities and duties

Qualifications of requirements

Designated responsible user

This is the clinical person

designated by the responsible

Purpose (i.e. definition of role)

Responsibilities and duties

Page 221: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

200

person who is in-charge of a

specific radiological installation

(e.g. responsible user, medical

director)

Qualification requirements

Procedure description for replacement of a designated

responsible user

Technical Director

This is the person who is

designated by the responsible

person to be in-charge of technical

aspects of the radiological

machine.

Purpose (i.e. definition of role)

Responsibilities and duties

Qualification requirements

Radiation Protection Supervisor Purpose (i.e. definition of role)

Responsibilities and duties

Qualification requirements

Radiation Protection Officer/

Radiation Safety Officer

Purpose (i.e. definition of role)

Responsibilities an duties

Qualification requirements

Authority and powers

Number of RPOs/RSOs required for operation

Qualified technical expert

(e.g. medical physicist)

Purpose (i.e. definition)

Responsibilities and duties

Qualification requirements

Persons responsible for the

radiation exposure

(e.g. medical practitioner)

Responsibilities and duties

Qualification requirements

Persons authorized to

prescribe/refer scans

Responsibilities and duties

Qualification requirements

Persons authorized to operate CT

scanner

Responsibilities and duties

Qualification requirements

Persons to assemble, install or

repair a CT scanner

Responsibilities and duties

Qualification requirements

Training programs and continuing

education

Training programs and/or continuing education are provided at

an institutional basis

Training programs and/or continuing education are provided or

required by supervisory authority

Content of radiation protection training programs

Alternative training programs are available for staff that do not

have the updated pre-requisite qualifications

Educational programs are formulated with input from

professional associations, and are evidence-based

Financial assistance may be provided for training and continuing

education courses in radiological protection by the responsible

agency

Frequency of qualification updates

Exemptions from the qualification requirements

Enforcement actions if professionals do not meet the

qualification requirements within a specified timeframe

Recordkeeping Requirements Requirements for recordkeeping of staff qualifications

Procedure description for the responsible authority to obtain the

Page 222: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

201

records when required

Accountability Accountability for different situations of each staff role

Clear cut lines of responsibility of each stakeholder involved in

medical exposure radiation protection

Institutional Radiation Protection Committee or Quality Assurance Committee

Committee set-up Criteria for establishing a committee (e.g. members)

Responsibilities and duties

Criteria to develop radiation protection or quality assurance plan

Content that should be included in the radiation protection or

quality assurance plan

Requirements to regularly review plan

Indicators and targets are set in the plan

Procedure to verify and/or validate key operational processes

Clinical risks are systematically identified and assessed

Requirements for a radiation expert (e.g. medical physicist) to

consult

Establishment of a feedback/commenting system for

professionals to discuss the optimization mechanisms

Establishment of a program to systematically replace equipment

before deterioration to an unacceptable level (e.g. increased

radiation output)

Patients’ rights are known to staff and available to patients

Procedure to disseminate performance of equipment, operational

procedures and other QA initiatives to staff and other interested

parties

Committee Meetings Required frequency of meetings

Documentation of each committee meeting and/or required

records as part of the radiation protection/quality assurance

program

Time frame to maintain quality assurance records and meeting

minutes

Accountability to

responsible/supervisory committee

External consultation requirements to add transparency

Criteria that are assessed in QA assessments by

responsible/supervisory authority

Physician peer-review program establishment

Sample examinations are to be submitted periodically to a

responsible/supervisory authority for image quality assessment

Competency of staff are assessed periodically

Requirements to submit activity reports (e.g. frequency of

submissions, content of reports)

Patient Records and Patient Medical Reports

Patient record requirements Information that needs to be recorded for each patient regarding

CT dose- Exposure records for patients

A record of all images taken should be maintained

Explanation of the limitations for recordkeeping requirements

for diagnostic CT dose recordkeeping

Process description for verification of recorded doses by a

qualified expert

Guidance from responsible/supervisory authority on what

Page 223: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

202

constitutes “greater than expected” doses

Standardized report format to ensure sufficient information is

available for diagnosis

Process description to explain recordkeeping requirements

Timeframe for patient recordkeeping

Procedure description for the transfer of medical records in the

event of a discontinuation of practice

Sharing of patient records Procedure for the sharing of images between healthcare

professionals

Procedure to communicate significant changes in the

interpretation of patient records

Emergency Situations and Event Reporting

Institutional requirements for

emergency radiation incident

situations

Procedure to establish a radiation incident reporting system

Procedure to conduct internal investigations

Objectives and criteria for internal investigations

Procedure to implement changes/recommendations following

investigation

Recordkeeping requirements of investigation details

Reporting requirements to the

supervisory authority

Conditions that require reporting of results to responsible

authority (e.g. repeated scans, scans over a specified dose limit

for a specific body part)

Criteria/Format of the incidents report to be submitted

Recordkeeping requirements

Exemptions from event reporting (e.g. increased doses form

ageing equipment)

Timely dissemination of information, including lessons learned

Notification requirements Time-frame to notify the supervisory authority

Responsibility to notify the patient that was subject to the event

Time-frame to notify the patient that was subject to the event

Responsibility to notify the referring physician

Time-frame to notify the referring physician

Diagnostic reference levels

Institutional diagnostic reference

levels

Institutional diagnostic reference

levels (continued)

Local diagnostic reference levels are required to be established

Provide guidance on how to establish DRLs

Regular review and update of the DRLs

Discussion of body dose thresholds and is a requirement in the

plan

Patient dose levels are periodically compared with the official

DRLs (or other external benchmark)

Compliance with jurisdictional DRLs is checked by a qualified

expert (e.g. medical physicist, license holder, radiation

protection officer)

Internal protocol to review whether radiation protection has been

optimized if DRLs are consistently exceeded

Procedure to investigate substantially low doses (i.e. in

situations where images do not provide useful diagnostic

information)

Official jurisdictional diagnostic

reference levels

Purpose of DRLs (i.e. definition)

Official guidance values (i.e. DRLs) are provided for specific

Page 224: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

203

routine scans

DRLs are updated periodically

Explanation for a lack of dose limits for medically exposed

peoples

Provide guidance on management of exposures

Accountability with DRLs Requirement for explanation to supervisory authority if DRLS

are consistently exceeded

Medical radiation exposure of population groups are regularly

investigated and compared to national levels by the supervisory

authority

Results of non-compliance

General outcomes of non-

compliance information

Description of unlawful actions that can result in punitive and/or

corrective actions

Results of an offence committed by an individual vs. the body

corporate are separately listed

Limitation of liability claims

Criminal Provisions Possibility of any judicial involvement or criminal prosecution

Responsibilities and duties of person who is charged for an

offence

Definitions for judicial provisions (e.g. hearing location,

prepared testimony, non-part witness)

Any criminal penalties are stated in relation to the offense

Process description for appeal process of criminal charges

Monetary Penalties Procedure description for payment of fines

Monetary fines are stated in relation to the offense

Procedure to settle monetary penalties via negotiations

Severity levels Description of a gradual severity level system for violations

Criteria to change severity levels of violations

Seizure or forfeiture of property Process description for order of forfeiture of property

Process description for seizure of suspected unsafety property by

the inspector (e.g. warrants that need to be obtained)

Process description to provide the supervisory authority or

license holder a list of seized property

Compensation for damage to seized equipment

Process description for the return of seized property, or the

process to extend the seizure period if reasonable

Possible outcomes of the seized property

License Violations Process description for the notification of license holder of non-

compliance

Explanation of timeline and conditions for holder to regain

suspended license

Procedure for license holder to address the situation when a

license has been violated (e.g. instructions from licensing

authority to rectify violations)

Informal conference offered to license holder in case of

violations

Page 225: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

204

Part 2: Legislation Assessment

Legislation is law that has been enacted by a governing body to address a social, economic or political

need [101]. Legislations are legally binding and can be enforced by the courts. There are three types of

legislation- statutes, regulations and bylaws. Statutes are broad, governing principles or rules that are

publicly debated by the governing body and voted upon before coming into regulation, ordinances and

bylaws are the details of operation and implementation that support the statute [73].

Radiation protection legislation use the force of law to ensure that the use of ionizing radiation generators

are installed and operated effectively and safely. Depending on the analyzed jurisdiction, there may be

two types of legislation that can be analysed for computed tomography (CT) radiation regulation. Firstly,

each country has general radiation protection legislation that may be applied to any atomic energy

generation, including ionizing radiation producing devices. Some jurisdictions may also have medical

exposure or healthcare specific radiation protection legislation.

Domain Selection

Legislations are initiated to translate a governmental policy decision into an implementable solution that

can achieve the intended objectives. The ultimate goal of legislation development is to achieve good

governance, so that its purpose can be accepted with support from the targeted users [107]. The domains

were, therefore, selected to reflect the characteristics that have a positive effect (i.e. gain support from

target users) on legislation development and implementation. Selected domains were then made specific

to the radiation protection context. Part 2 of this assessment can be applied to systematically evaluate and

compare the quality of radiation protection legislations undertaken by various jurisdictions.

Rating Scale

Each of the domains are designed to be rated on a 5-point Likert Scale, which is an ordinal level of

measurement that can be used to qualitatively score a domain. As with all Likert Scale measurements, the

rating scale is limited by the required subjectivity of the rater [99]. In a systematic comparison of the

jurisdictional radiation protection legislations, the scale can be used to distinguish an inter-jurisdictional

rank order for each assessed domain.

A domain may be evaluated for several different criteria, where each criterion may have its own rating

scale. The criteria should first be scored individually, and then, an overall domain score should be

provided by the rater after consideration of each criterion score. Additional information is provided for

each score on the rating scale. This information is not intended to offer absolute standards for scoring

Page 226: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

205

each domain, but rather, help facilitate the user’s assessment. It is important to note that there is no

absolute formula to calculate an overall domain score, and legislation rating will require a level of

judgment. It is recommended that the Comments section for each domain score sheet be completed by

each rater to facilitate inter-rater discussions between evaluation rounds, if multiple rounds are required.

Descriptions and the key considerations will be provided to guide the judgment of the rater. The provided

description explains how the selected assessment characteristic affect the quality of the legislation. This

section provides a broad statement of the minimal expectations that should be met to fulfill the domain.

The Key Criteria that should be considered in the Legislation Content section identify explicit elements

that should be evaluated in accordance with the Description. A higher score for a legislation will both:

i. Meet more listed criteria; and

ii. Fulfill each criterion to a fuller extent in accordance with the description.

Inter-rater Reliability

It is recommended that a minimum of 2 raters use the assessment framework to evaluate the radiation

protection regulatory structure for each jurisdiction such that inter-rater reliability can be calculated to

ensure reproducibility of the assessment results. To account for inter-rater reliability, the weighted

Cohen’s κ for each domain, and 95% confidence interval that the agreement is better than chance will be

calculated. Weighted Cohen’s Kappa is designed to be used with ordinal data such as Likert Scales

because it accounts for partial agreement, which is useful for inter-rater reliability [122]. For example, a

score difference of 4 should be seen as a lower reliability than a score difference of 1. The Fleiss

Benchmark Scale should be used to evaluate the level of agreement; where κ values <0.40, 0.40 to 0.75,

and >0.75 represent poor, intermediate to good and excellent agreement, respectively [123].

If inter-rater reliability is insufficient (aggregate κ < 0.75), a discussion should be held to propose

clarifications for the applications of each domain’s evaluation criteria. Final scores for each domain

should be achieved through consensus once κ is satisfactory. The final agreed upon scores and aggregate

score will facilitate subsequent comparative analysis of the jurisdictions.

Domain 1: Clarity and Presentation of Legislative Scope

Description

A well-structured legislation written in clear, concise and plain language is intended to assist and guide

the authoritative body, target users and general public in deciding which action is most likely to be the

most appropriate to resolve any problem [101], [106]. It is, therefore, important that the legislation clearly

Page 227: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

206

communicates its goals, and the situation in which it applies (i.e. scope) [101]. The means to achieve the

goals should also be indicated with clarity.

Key Criteria in Legislation Content

1. Are there contradicting sections in the written legislation?

2. Is the scope of the legislation defined?

o Is the purpose for the legislation development described?

o Can the target population(s) be clearly identified by the general public?

o Are the problems that the legislation is designed to address defined?

3. Is the legislation intelligible by the technical users and the general public?

Criterion 1:

0 1 2 3 4

There scope is broad,

and it is stated with

ambiguous language

The scope is

broad, but it is

stated with

concise language.

The scope is somewhat

defined, but it is stated

with ambiguous

language.

The scope is defined,

and stated with

unambiguous

language.

The scope is very clearly

defined, and stated with

concise and unambiguous

language.

Criterion 2:

0 1 2 3 4

The writing is

confusing, and

requires

clarifications

for both

intended users

and the general

public.

The writing is

technical and

written for

understandability

for targeted users.

The general public

will require

substantial

clarification.

The writing is

technical, and

written for

understandability for

targeted users. The

general public will

require some

clarification.

The writing is

technical, and

written for

understandability

for the technical

users. The general

public will require

minimal

clarification.

The writing is

plain, and

written for

understandability

by the general

public and

technical users.

Overall Score

0 1 2 3 4

Extremely poor Below Average Acceptable Good Excellent

Comments:

Click here to enter text.

Page 228: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

207

Domain 2: Transparency

Description

It is important that official business is conducted in such a way that procedural information is available

and broadly understandable by people and groups in society. Transparency can simply be defined as a

clear and open explanation as to what is being done, how and why actions are taking place and who is

involved [107]. The accessibility to information in a transparent regulatory structure allows organizations

(i.e. institutions) to plan their business and routines accordingly and with confidence [105].

Key Criteria to Consider in Legislation Content

1. Are the relevant processes for CT operation understandable? Are there details included in the

following procedures:

a. Licensing (e.g. fees, requirements)

b. Accreditation (e.g. fees, accredited organization)

c. Inspection (e.g. frequency, enforcement of non-compliance)

d. Compliance requirements (e.g. local DRL establishment)

2. Are independent (non-governmental) experts invited to perform technical reviews or offer

technical opinions?

3. Are the appointments of inspectors and responsible authorities accountable to public and political

leadership?

4. What information are available to the public (e.g. radiation risk information, hospital

accreditation status)?

a. How can the public access the information provided by the regulatory organization?

5. Can the public openly participate in the legislative process?

Criterion 1:

0 1 2 3 4

The processes included in

the legislation not defined.

Insufficient information is

provided for the execution

of action plans. All of the

processes require

clarifications.

The processes

included in the

legislation are not

well-defined. Most

processes require

clarification.

The processes

included in the

legislation are

somewhat defined.

Some processes

require

clarifications.

The processes

included in the

legislation are

defined. Minimal

clarifications are

required.

The processes

included in the

legislation are very

clearly defined. No

additional

clarifications are

required.

Criterion 2:

0 1 2 3 4

Information is

inaccessible to the

public and to the

target population.

Information may be

requested by target

users, but it is not

accessible to the

general public.

Information must be

systematically

requested by both

targeted users and the

general public.

Information is readily

accessible to the target

population, but the

general public must

systematically request the

Information is readily

accessible to the general

public and the target

population for the

legislation.

Page 229: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

208

information.

Overall Score

0 1 2 3 4

Extremely poor Below Average Acceptable Good Excellent

Comments:

Click here to enter text.

Domain 3: Accountability

Description

Accountability ensures that facilities administering CT scans account for their activities, accept

responsibility for them, and disclose the results in a transparent manner. Formal checks and balances

should be built into the legislation, such that there are procedures requiring officials to follow established

rules defining acceptable processes and outcomes, which are then reviewed on a regular basis [107].

Horizontal accountability allows one part of a government to stop or correct another sector or branch of

the government, while vertical accountability ensures that the government answers to citizens [107].

Key Criteria to Consider in Legislation Content

1. Is the responsible authority for the radiation protection stated?

o What are the powers that are available to the responsible authority, inspectors and other

staff that act on behalf of the responsible authority?

o Is the contact information for the responsible authority available?

2. Is there an understandable and transparent procedure for the enforcement of non-compliance? For

example:

o Definition of punishment for offences,

o The procedure for suspension of license

o The procedure for license removal

3. For horizontal accountability, are other branches of the government:

o Able to request access to information (e.g. audit documentation, institutional reports)

o Provided with defined powers to question the responsible authority

o Participating in the consultation for the legislative development

4. For vertical accountability, are the following available:

o A system for general citizens to make complaints

o Definition of punishable actions

Criterion 1:

Page 230: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

209

0 1 2 3 4

The responsible

authority, punishable

actions and enforcement

procedures are not

defined.

The responsible

authority, punishable

actions and enforcement

procedures are poorly

defined.

The responsible

authority, punishable

actions and

enforcement

procedures are

somewhat defined.

The responsible

authority,

punishable actions

and enforcement

procedures are

defined.

The responsible

authority, punishable

actions and

enforcement

procedures are very

clearly defined.

Criterion 2:

0 1 2 3 4

Horizontal

accountability measures

are not considered and

not defined.

Horizontal

accountability measures

are implicit and poorly

defined

Horizontal

accountability

measures are implicit

and somewhat

defined.

Horizontal

accountability

measures are

evident and defined.

Horizontal

accountability

measures are evident

and very clearly

defined.

Criterion 3:

0 1 2 3 4

Vertical accountability

measures are not

considered and not

defined.

Vertical accountability

measures are implicit

and poorly defined

Vertical

accountability

measures are implicit

and somewhat

defined.

Vertical

accountability

measures are

evident and defined.

Vertical

accountability

measures are evident

and very clearly

defined.

Overall Score

0 1 2 3 4

Extremely poor Below Average Acceptable Good Excellent

Comments:

Click here to enter text.

Domain 4: Rigor of Compliance Requirements

Description

Compliance with the regulations should be easily assessable. Common strategies to monitor compliance

include periodic review and other supervision measures [102]. Supervision is required to:

I. Measure the progress or lack thereof in implementing the legislation [102]

Page 231: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

210

II. Identify and address problems of possible risks [102]

III. Take corrective action in a timely manner [102]

Key Criteria to Consider in Legislation Content

1. What are the requirements to achieving compliance?

2. How often are inspections or audits by the representative of the responsible authority performed?

o Is the representative of the responsible authority required to document all audits?

3. Are records of internal audits required to ensure continued institutional compliance?

o How often are these records reviewed by an independent reviewer or by accreditation

authorities?

o What are the consequences of non-compliance?

4. Is there a clear agenda for the compliance and monitoring system?

o Are the compliance measures taken aligned with the policy objectives?

Criterion 1:

0 1 2 3 4

No burden of evidence

is required by the

authoritative body.

Burden of

evidence is

minimal.

Some evidence

is required.

Reasonably high amount of

evidence is required, but

additional evidence may be

acquired.

Maximum amount of evidence

is required to ensure intent of

regulation is achieved.

Criterion 2:

0 1 2 3 4

There are no

compliance checks

or monitoring

systems in place.

There are compliance

checks only when

persistent complaints

are made by general

users.

Compliance checks

and monitoring

occur periodically,

but there is no

specified frequency.

Compliance checks and

monitoring are fairly

frequent.

Compliance checks and

monitoring are very

frequent.

Overall Score

0 1 2 3 4

Extremely poor Below Average Acceptable Good Excellent

Comments:

Click here to enter text.

Page 232: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

211

Domain 5: Outcomes of non-compliance

Description

Legislation may address lack of compliance through sanctions and/or support strategies. The imposition

of sanctions may include penal sanction (e.g. fines, imprisonment) and administrative sanctions (e.g.

license suspension) [106]. Support based strategies may include personalized training and help with re-

organization the radiation department structure. Both strategies may be useful in achieving the intended

objectives of the legislation, and should be assessed for their effectiveness.

Key Criteria in Legislation Content

1. Are there clear definitions of offences that result in imposition of sanctions for violations?

2. What methods are used to impose sanctions for non-compliance? Consider:

a. Penal sanctions

b. Administrative sanctions

c. Support strategies

3. Who holds the enforcement powers?

4. Is the process for determining sanctions transparent and clear? For example:

a. The key criteria for monitoring or audits are summarized

b. There is a gradual increase in severity of punishments

5. To what extent is support offered by the authoritative body?

a. How customized is the support offered?

b. Can the representative suspend licenses until recommendations are met?

Overall Rating Scale

0 1 2 3 4

Violations have weak

sanctions for non-

compliance

OR

Weak support is offered

by government to

achieve compliance.

Violations have

moderate sanctions

for non-compliance

OR

Moderate support is

offered by the

government

Violations for non-

compliance will receive

moderate sanctions

AND

moderate support is

provided by the

government

Violations will result

severe sanctions

OR

Strong support is

provided for

institutions struggling

to meet compliance

Violations for non-

compliance will

receive severe

sanctions

AND

moderate support is

provided by the

government

Comments:

Click here to enter text.

Page 233: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

212

Domain 6: Fairness

Description

Legislation should be impartial and treat all institutions (whether private or public) with the same

minimum level of expectations. This does not suggest that the paths to achieving compliance are the same

for all institutions, but rather, equitable processes [107] are ensured in that all institutions (e.g. large or

small, private or public) are provided with equal opportunity to achieve compliance. For example, the

establishment of a radiation protection committee at the institutional level may be an explicit expectation

in a legislation. To provide an equitable path to compliance, smaller institutions with less beds, less

human resources and lower patient volumes may join other small institutions to form a radiation

protection committee.

Equity in legal writing uses gender neutral, and non-discriminatory language. Equitable legislations allow

users to be confident and aware of actions that must be taken to comply with them and the consequences

of those actions and of non-compliance.

Key Criteria in Legislation Content

1. Does the legislation address both public and private institutions?

a. Are the two types of institutions held to the same standard?

b. Are the funding sources equivalent for both types?

2. Is the legislation written in gender neutral and non-discriminatory language?

3. Are options available for different types of institutions?

a. Do these options consider the workflow, culture and type of the institution?

b. Does the responsible authority offer support to customize executable alternative action

plans for different institutions?

4. Does the legislation offer guidance in the decision-making process for target users, and the

responsible authority?

Criterion 1:

0 1 2 3 4

The legislation

explicitly

favours a

specific type of

institution.

The legislation

implicitly

favours a

specific type of

institution.

Non-discriminatory

language is not

explicitly evident, but

institution-type

neutrality is implied.

It is evident that the

legislation attempts to use

non-discriminatory

language to display

institution-type neutrality.

It is very evident that the

legislation uses non-

discriminatory language,

and all institution types are

treated fairly.

Criterion 2:

0 1 2 3 4

All institutions types are

assumed to be the same,

It provides fair and

equitable terms for a

It provides fair and

equitable terms for

It provides fair and

equitable terms for

It provides fair and

equitable terms for

Page 234: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

213

therefore, fair and equitable

terms are not available for

all user types. The action

plans provided does not

allow for alternative

execution to meet minimum

expectation.

small number of

users. Options are

provided for few

possible institution

types to fulfill the

minimum

expectations of the

legislation.

some users. Options

are provided for some

possible institution

types to fulfill the

minimum

expectations of the

legislation.

most users. Options

are provided for

most possible

institution types to

fulfill the minimum

expectations of the

legislation.

all users. Options

are provided for all

possible institution

types to fulfill the

minimum

expectations of the

legislation.

Overall Score

0 1 2 3 4

Extremely poor Below Average Acceptable Good Excellent

Comments:

Click here to enter text.

Part 3: Supplemental Documents Assessment

Supplemental documents to legislation are designed to optimize the implementation of legislation by

providing guidance for specific circumstances. In radiation protection, the available supplemental

documents usually range from clinical practice guidelines by the medical authority to accreditation

standards and guidelines from the official licensing body in the jurisdiction. These documents are usually

not legally binding and should “include recommendations that are informed by a systematic review of

evidence and provide an assessment of benefits and harms of alternative care options [109].”

Domain Selection

The potential benefits of these supplemental documents can only be fully achieved if they have been

developed using appropriate methodologies and employ rigorous strategies to overcome knowledge

translation barriers. Knowledge translation refers to the synthesis, exchange and application of research

evidence by relevant stakeholders to inform and improve healthcare systems and people’s health [110].

This complex interactive process requires a document to present information in a distinct format that

satisfies multiple attributes. Therefore, the domains below represent recurring attributes that have been

found to positively influence document implementation into clinical practice and negate common

knowledge translation barriers. Selected domains have been refined to emphasize the radiation protection

context.

Page 235: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

214

Rating Scale

Each of the domains are designed to be rated on a 5-point Likert Scale, which is an ordinal level of

measurement that can be used to qualitatively score a domain. As with all Likert Scale measurements, the

rating scale is limited by the required subjectivity of the rater [99]. In a systematic comparison of the

supplemental documents, the scale can be used to distinguish an inter-jurisdictional rank order for each

assessed domain.

A domain may be evaluated for several different criteria, where each criterion may have its own rating

scale. The criteria should first be scored individually, and then, an overall domain score should be

provided by the rater after consideration of each criterion score. Additional information is provided for

each score on the rating scale. This information is not intended to offer absolute standards for scoring

each domain, but rather, help facilitate the user’s assessment. It is important to note that there is no

absolute formula to calculate an overall domain score, and legislation rating will require a level of

judgment. It is recommended that the Comments section for each domain score sheet be completed by

each rater to facilitate inter-rater discussions between evaluation rounds, if multiple rounds are required.

Descriptions and the key considerations will be provided to guide the judgment of the rater. The provided

description explains how the selected assessment characteristic affect the quality of the legislation. This

section provides a broad statement of the minimal expectations that should be met to fulfill the domain.

The Key Criteria that should be considered in the Legislation Content section identify explicit elements

that should be evaluated in accordance with the Description. A higher score for a legislation will both:

i. Meet more listed criteria; and

ii. Fulfill each criterion to a fuller extent in accordance with the description.

Inter-rater Reliability

It is recommended that a minimum of 2 raters use the assessment framework to evaluate the radiation

protection regulatory structure for each jurisdiction such that inter-rater reliability can be calculated to

ensure reproducibility of the assessment results. To account for inter-rater reliability, the weighted

Cohen’s κ for each domain, and 95% confidence interval that the agreement is better than chance will be

calculated. Weighted Cohen’s Kappa is designed to be used with ordinal data such as Likert Scales

because it accounts for partial agreement, which is useful for inter-rater reliability [122]. For example, a

score difference of 4 should be seen as a lower reliability than a score difference of 1. The Fleiss

Benchmark Scale should be used to evaluate the level of agreement; where κ values <0.40, 0.40 to 0.75,

and >0.75 represent poor, intermediate to good and excellent agreement, respectively [123].

Page 236: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

215

If inter-rater reliability is insufficient (aggregate κ < 0.75), a discussion should be held to propose

clarifications for the applications of each domain’s evaluation criteria. Final scores for each domain

should be achieved through consensus once κ is satisfactory. The final agreed upon scores and aggregate

score will facilitate subsequent comparative analysis of the jurisdictions.

Domain 1: Clarity of Scope and Purpose

Description

The supplemental documents to Radiation Protection legislation provide additional guidance in the

streamlining and implementation of recommended practices or sound practice. The scope of each

document defines the range of situations it will address. A well-defined scope will increase

comprehension and application by users and the general public. A well-defined scope and purpose should

answer:

I. Goal or objective of the document

II. Targeted health problem or technology

III. Targeted patient populations(s); intended users or audience

IV. Practice setting for which guideline is intended

V. Rationale for why and how the document was developed

Key Criteria to Consider in the Supplemental Document Content

1. Does the document include an introduction or background section that explains the goal or

objective of the document, and a rationale that explains the need for this document?

2. Are there contradicting sections in the written document?

3. Is the legislation intelligible by the technical users and the general public?

Criterion 1:

0 1 2 3 4

The goal, target health

problem, target

population and

appropriate practice

setting is broad and not

well defined.

ONE of the goal,

target health problem,

target population and

appropriate practice

setting is defined.

TWO of the goal, target

health problem, target

population and

appropriate practice

setting are defined.

THREE of the goal,

target health problem,

target population and

appropriate practice

setting are defined.

The goal, target health

problem, target

population and

appropriate practice

setting are clearly

defined.

Criterion 2:

0 1 2 3 4

No rationale for the

development of the

document is provided.

Users are expected to

Minimal rationale

for the development

of the document is

provided.

Some rationale for the

development of the

document is provided.

Some additional

Adequate rationale for

the development of

the document is

provided. Minimal

An in-depth rationale

for the development of

the document is

provided. No additional

Page 237: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

216

implicitly understand

the importance of the

document.

clarification is required. clarifications are

required.

clarification is required.

Criterion 3:

0 1 2 3 4

The writing is

confusing, and

requires

clarifications for

both intended users

and the general

public.

The writing is technical

and written for

understandability for

targeted users. The

general public will

require substantial

clarification.

The writing is technical,

and written for

understandability for

targeted users. The

general public will require

some clarification.

The writing is technical,

and written for

understandability for

the technical users. The

general public will

require minimal

clarification.

The writing is

plain, and written

for

understandability

by the general

public and

technical users.

Overall Score

0 1 2 3 4

Extremely poor Below Average Acceptable Good Excellent

Comments:

Click here to enter text.

Domain 2: Evidence support and explanation for processes and recommendations

Description

A key feature of the supplemental documents is the recommendations for best practice in radiation

protection for ionizing radiation in medical exposures. These recommendations represent the central aim

of the supplemental documents and therefore, they should be supported with relevant evidence from

clinical and scientific research. The supplemental document should clearly describe the method of

evidence retrieval, time period from which the evidence is retrieved and the significance of the evidence.

Alternatively, some best practice recommendations may only require a detailed, logical explanation of the

decision-making process for the inclusion of the recommendations. Whenever possible, the benefits and

costs of each recommendation should be made explicit to the intended audience.

Key Criteria to Consider in the Supplemental Document Content

1. Does the document make explicit references to other resources?

a. Alternatively, if no citation is available, does the document provide a logical and clear

explanation for its recommendation

2. Does the document explain how evidence was obtained?

Page 238: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

217

a. Were the methods systematic?

3. What was the method for selecting evidence?

a. Are the strengths, limitations, benefits and costs of each recommendation summarized?

4. Is there an explicit link between the recommendations and the supporting evidence (e.g. citation,

references, and explanations)?

Criterion 1:

0 1 2 3 4

There is no

evidence provided

for the

recommended

processes and

requirements.

The recommendations

for processes and

requirements are rarely

supported with credible

evidence and/or

explanations.

The recommendations

for processes and

requirements are

sometimes supported

with credible evidence

and/or explanations.

The recommendations

for processes and

requirements are

mostly supported with

highly credible

evidence and/or

explanations.

The recommendations

for processes and

requirements are

always supported with

highly credible

evidence and/or

explanations.

Criterion 2:

0 1 2 3 4

Benefits and costs of

recommended actions are not

analyzed. Users are expected to

blindly accept the

recommendations.

Benefits and costs of

a minimum number of

recommended actions

are analyzed.

Benefits and costs

of some

recommended

actions are

analyzed.

Benefits and costs

of most

recommended

actions are

analyzed.

Benefits and costs

of all

recommended

actions are

analyzed.

Overall Score

0 1 2 3 4

Extremely poor Below Average Acceptable Good Excellent

Comments:

Click here to enter text.

Domain 3: Instructive quality of writing

Description

The first dimension to actionable recommendations is to have clear and detailed descriptions of the

processes and recommendations. In order for institutions to adapt the recommendations and action plans,

these explanations should provide sufficient information regarding when an action needs to be performed,

how and why actions need to be performed and who is involved. Additionally, easy accessibility to the

document information will increase the actionability of the supplemental document writing.

Page 239: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

218

Key Criteria to Consider in the Supplemental Document Content

1. Are the descriptions of the recommendations written in a clear, concise and detailed manner?

2. Would an institution be able to follow the “instructions” to achieve compliance with the

recommendations?

a. Would further clarifications be required?

b. Is the writing unambiguous and specific?

c. Are the key recommendations easily identifiable?

3. Does the writing answer all the key criteria that is required to implement the recommendations?

4. Is the information easily accessible and transparent to the target users and the general public?

Criterion 1:

0 1 2 3 4

All of the

recommended

action plans

require additional

clarifications for

execution to be

possible.

Substantial additional

clarifications are

required to execute the

instructions for the

recommended action

plans.

Some additional

clarifications are

required to execute

the instructions for

the recommended

action plans.

Minimal additional

clarifications are

required to execute the

instructions for the

recommended action

plans.

No additional

clarifications are required

to execute the instructions

for the recommended

action plans.

Criterion 2:

0 1 2 3 4

Information is

inaccessible to the

public and to the

target population.

Information may be

requested by target

users, but it is not

accessible to the general

public.

Information must be

systematically

requested by both

target users and the

general public.

Information is readily

accessible to the target users,

but the general public must

systematically request the

information.

Information is

readily accessible to

the general public

and the target users.

Overall Score

0 1 2 3 4

Extremely poor Below Average Acceptable Good Excellent

Comments:

Click here to enter text.

Page 240: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

219

Domain 4: Adaptability

Description

Supplemental documents should be structured to address a wide range of situations while allowing for a

degree of flexibility. The document should provide a concrete and precise description of the desired

performance and describe which action plan is appropriate in each situation. Although a supplemental

document should address all foreseeable circumstances, it is unlikely that all possible situations can be

addressed within the scope of the supplemental document. Therefore, it is important that the

recommendations permit for interpretation and provide guidance for alternative action plans that may be

suitable when unforeseeable situations arise. Additionally, the clinical workflow for CT operation will

vary at each healthcare institution due to the differences in organizational structure and culture, which

will affect implementability of the recommendations. Any conditional factors that may influence

decision-making, performance and compatibility with local institutional norms and values should also be

described.

Key Criteria to Consider in the Supplemental Document Content

1. Does the document provide recommendations to different population types (e.g. children,

pregnant women)?

2. Does the document describe when a specific action plan should be used (i.e. link an action plan to

a situation)?

3. Does the document provide details regarding the implementation of its recommendations?

a. Are tools for application available?

b. Are limitations and potential barriers also noted?

4. Does the document consider hospital of varying sizes, hospital types (i.e. public or private,

academic or community), geographic location, and professional skill levels?

a. Are alternative plans provided for different institution types?

5. If alternative execution plans are provided for different hospitals, are the recommendations

written in a clear manner to ensure smooth implementation?

a. Are sufficient information provided to customize execution plans that will achieve

compliance?

6. Is there an option to contact the responsible authority for customized support?

Overall Score

0 1 2 3 4

Assumes only one

possible operation

condition (i.e. one

organization structure

type, one type of

clinical workflow, and

Few operation

conditions (e.g.

different

organizational

structures, clinical

workflows, level of

Some operation

conditions (e.g.

different

organizational

structures, clinical

workflows, level of

Most operation

conditions (e.g.

different

organizational

structures, clinical

workflows, level of

Management options

are provided for all

possible operation

conditions (e.g.

different

organizational

Page 241: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

220

the same level of

professional training,

skills and experience

for all institutions),

and only one possible

management option is

assumed

professional training,

skills and experience)

are discussed, and

management options

are provided for each

stated condition

professional training,

skills and experience)

are discussed, and

management options

are provided for each

stated condition

professional training,

skills and experience)

are discussed, and

management options

are provided for each

stated condition

structures, clinical

workflows, level of

professional training,

skills and experience)

based on current

knowledge

Comments:

Click here to enter text.

Domain 5: Integration of Inter-professional perspectives

Description

Radiation protection involves many different stakeholder ranging from medical physicists to radiologists,

therefore, it is important to consider the needs and priorities of each stakeholder group in the development

of the supplemental document. Ionizing radiation management within an institution requires co-operation

of many professional roles, so integration of inter-professional perspectives will increase credibility of

practice management amongst intended user groups. Furthermore, external peer review should be

performed whenever possible to demonstrate editorial independence and raise confidence amongst

targeted audience and users.

Key Criteria to Consider in the Supplemental Document Content

1. Does the documentation account for the different roles that are usually present on a radiation

protection committee (e.g. radiologist, medical director, medical physicist, and medical radiation

technologist)?

a. How detailed are the descriptions of the responsibilities and functions of each role?

2. Does the document explicitly explain which stakeholder opinions were involved in the

development of the document?

3. Can users be confident in the development of the document? Consider:

a. Is the document editorially independent from the funding source?

b. Are the conflicts of interest clearly recorded?

c. Did the document undergo peer review? If so, who was involved in this process?

Criterion 1:

0 1 2 3 4

Only one possible

radiation protection

stakeholder group at

the institutional

level based on

A minimum number of

possible radiation

protection stakeholder

groups at the

institutional level based

Some possible

radiation protection

stakeholder groups at

the institutional level

based on current

Most possible radiation

protection stakeholder

groups at the

institutional level based

on current knowledge

All possible radiation

protection stakeholder

groups at the

institutional level

based on current

Page 242: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

221

current knowledge

have been

considered, and

only one role is

described in the

document.

on current knowledge

have been considered,

and limited stakeholder

groups are provided

with a role at the

institution.

knowledge have been

considered, and some

stakeholder groups

are provided with a

role at the institution.

have been considered,

and most stakeholder

groups are provided

with a role at the

institution.

knowledge have been

considered, and each

group is provided a

role at the institution.

Criterion 2:

0 1 2 3 4

Each stakeholder

group’s

qualification

requirements,

responsibilities and

functions are

defined.

Each stakeholder

group’s qualification

requirements,

responsibilities and

functions are poorly

defined.

Each stakeholder

group’s qualification

requirements,

responsibilities and

functions are

somewhat defined.

Each stakeholder

group’s qualification

requirements,

responsibilities and

functions are defined.

Each stakeholder

group’s qualification

requirements,

responsibilities and

functions are very

clearly defined.

Criterion 3:

0 1 2 3 4

There is no

peer review

process for

the

development

of the

document.

A peer review process

is clearly described for

the development of the

document, but it does

not involve an external

committee.

An external peer

review process for the

development of the

document is

mentioned, but there

are no details

provided.

An external peer review process

for the development of the

document is described, but

additional information can be

provided to strengthen the

confidence of users.

A clear explanation

of an external peer

review process for

the development of

the document is

described.

Overall Score

0 1 2 3 4

Extremely poor Below Average Acceptable Good Excellent

Comments:

Click here to enter text.

Page 243: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

222

Domain 6: Rigor of expectations

Description

Each supplemental document is designed to provide recommendations and guidance in achieving

compliance with the radiation protection legislation. The amount of work (i.e. rigor) required to achieve

compliance will vary with each document. A high level of social infrastructure (e.g. enhanced

communication between different levels of healthcare), organizational commitment (e.g. establishment of

inter-professional committees) and jurisdictional resources (e.g. frequent inspections by auditors) will be

more likely to result in successful uptake of the supplemental document’s recommended action plan.

Key Criteria to Consider in the Supplemental Document Content

1. Does the document require:

a. Establishment of new quality assurance committees

b. Human resource changes (e.g. hiring of a medical physicist)

c. Reporting of doses to the jurisdiction

d. Establishment of standard operating procedures for scanning protocols

e. Clinical justification for diagnostic scans

f. Frequent reporting of incidents

g. Establishment of local diagnostic reference levels

h. Compliance with jurisdictional diagnostic reference levels

i. Special procedures for vulnerable populations

j. An external peer review process for CT images

k. Any other processes required for the fulfillment of compliance

Overall Score

0 1 2 3 4

Compliance is not

monitored

(i.e. no work is

required to

achieve

compliance)

Minimal work based

on current knowledge

is required to achieve

compliance (i.e.

fulfillment of 1-3

possible

requirements)

Some work based on

current knowledge

(i.e. fulfillment of 4-6

possible

requirements) is

needed to achieve

compliance

Most of the possible

requirements based on

current knowledge (i.e.

fulfillment of 7-9

possible requirements)

is needed to achieve

compliance

Maximum amount of

work based on current

knowledge (i.e.

fulfillment of 10+

possible requirements) is

needed to achieve

compliance

Comments:

Click here to enter text.

Page 244: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

223

Domain 7: Rigor of Updates

Description

As new technology emerges, the described recommendations may be void. It is important to evaluate the

frequency of updates and the validity of the provided information. Current and valid information will

increase the confidence amongst intended users.

Key Criteria to Consider in the Supplemental Document Content

1. Is the document transparent about the frequency of updates to the available information?

a. Does the organization responsible for publication explain the plan for updates?

2. Does the document provide the date of publication, and the publication dates of all references?

Criterion 1:

0 1 2 3 4

The document does

not include an

explanation to validate

the information

provided in the

document.

The document admits to the

information being outdated

(e.g. not applicable due to

technology changes since

information retrieval).

The document

implies that the

information is

valid.

The document briefly

notes the validity of

the information

provided in the

document.

The document has a

clear explanation to

validate the

information provided

in the document.

Criterion 2:

0 1 2 3 4

The document does

not describe a plan for

frequency of updates

or a method for

updates.

The document notes

either a plan for

frequency of updates

OR a method for

updates.

The document clearly

describes either a plan

for frequency of

updates OR a method

for updates.

The document briefly

notes a plan for

frequency and method

for updates.

The document clearly

explains the planned

frequency and method

for updates.

Overall Score

0 1 2 3 4

Extremely poor Below Average Acceptable Good Excellent

Comments:

Click here to enter text.

Page 245: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

224

Appendix F: Legislation and Supplemental Document Quality Assessment Results

Part 2: Legislation Quality Assessment Results

Table F- 1: The detailed results of the legislation quality assessment for Australia, BC, California, Euratom and Germany. The comments explain the reasons for the scores. The

legislation documents highlighted with red font in Table 5 were analyzed for the legislation assessment.

Domain Criterion Australia BC1 California Euratom Germany

Clarity and Presentation of Legislative

Scope

Criterion 1 (Definition of

scope and language)

Code- 4; Act-2 (Average-3)

4

3 (Scope is defined, and the information available in the

document is laid out. However, it is written for all

radiation sources so it is not very specific)

4 (defines all medical exposures that are

applicable)

3 (The Scope is defined, but the document is written for a broad

spectrum of radioactive applications)

Criterion 2 (Writing style)

Code- 4; Act-3 (Average-3)

4

1 (The writing is written in legal jargon that makes it

very hard to understand by general public; harder to understand compared to

Australia's general act which uses simpler

vocabulary )

4 (easy to understand vocabulary)

2 (The ordinance is written with legal jargon. There is confusion with the vocabulary that is

used)

Overall Quality

3 4 2 4 2

Comments The code of practice by ARPANSA is a lot more

specific compared to the General Act which is

written with more legal jargon

Designed for all diagnostic modalities,

with one part specifically for

Computed Tomography

Transparency

Criterion 1 (Description of

processes)

Code-3; Act-4

3 (there are some very ambiguous

requirements for the processes that are

expected, but there is no guidance on how to fulfill the requirements)

2 ("Commands" are given to the supervisory

authorities to develop programs, however, there are no clear instructions)

3 (States what each member state should

do-commands; but there is some guidance

as to how the states can do it; for example, how to establish DRLs using dose estimates from the population)

3 (The requirements set out in this ordinance is fairly detailed, and it

provides some guidance on what needs to be

done)

Page 246: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

225

Domain Criterion Australia BC1 California Euratom Germany

Transparency (continued)

Criterion 22

(Accessibility of

information)

1

3 (Information may be disclosed to patients regarding incidents;

patients are involved in decision making and their rights are made

transparent; the accreditation status of the hospitals must also

be displayed)

0 (not sure if public and targeted users can request

information)

3 (they do not actually collect records except

the information of who is the representative

authority in each state, in which case, it is easily

accessible)

0 (Not sure if the information collected by

the authorities can be accessed by the public)

Overall Quality

2 3 1 3 1

Comments None of the information

is made publicly available, except notifications to the subject of radiation incidents are required.

Accountability

Criterion 1 (Description of

responsible authority,

punishable actions and

enforcement procedures)

Act-3; Code-1; average-2

2 (There is some ambiguity in terms of what is involved for accreditation with a

report and what is non-accreditation)

4

2 (No explicitly stated enforcement

procedures or punishable actions if

states do not transpose into member state law)

3 (Missing the types of penalties for each action)

Criterion 2 (Horizontal

accountability)

Act-3; Code-0; average 1

2 (Peer-review program is involved. In terms of

for the responsible authority, there is

none)

1 (Each authority works independently and have

individual responsibilities, but there are requirements

to be fulfilled for other organizational bodies like

accreditation authorities, as well as terms for

collaboration with other governments)

0 (This is based on the member state structure

but the measures are not explicitly required)

0 (No peer review programs, no collaboration)

Page 247: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

226

Domain Criterion Australia BC1 California Euratom Germany

Accountability

Criterion 3 (Vertical

accountability)

Act-3; Code-2; average-3 2

3 (There are requirements for facilities trying to get

their licenses, with requirements for follow-up

inspections and other records. For example, the

verification of dose by physicists.)

3 (suggests that institutions

communicate their findings to the

responsible authority of each member state (For example, regular review

of the DRLs), and the roles of each authority should be given to the

Euratom)

3 (Institutions--> Medical Council--> BfS)

Overall Quality

2 2 2 2 2

Comments Horizontal accountability is stated in the Act due to the different sub-councils

that are available. Vertical accountability is also explained in the act through the requirement of reports to the CEO. The submission of records is

implicit in the Code.

Rigor of Compliance

Requirements

Criterion 1 (Burden of evidence)

Code- 2; Act-1; Average 2 2(Inventory lists, NO

records of work done, NO QA documentation)

1 (inventory list, patient dose records) No records

for work that's done, or QA records)

3 (Inventory list, inspection records, NO records for work done,

standard protocols, qualification of staff, dose records, official

DRLs, radiation incidents)

2 (inventory checklists, protocols, qualification of

staff, patient dose records etc. NO radiation incident reports, limited inspection checklists and

QA checks)

Criterion 2 (Compliance monitoring)

Act-2; Code-0; Average 1

3 (4 year accreditation cycle. These are pre-

announced visits, which may not be truly

reflective of how the institution operates)

4 (3 year inspection frequencies, which is not very frequent. However,

they have to be accredited as well, which adds to their

frequency of checks)

2 (recommended inspections at regular

intervals)

2 (Medical Bodies perform QA checks on

the institutions and inform the authority if

there are any problems; institutions do not do the

reporting)

Page 248: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

227

Domain Criterion Australia BC1 California Euratom Germany

Rigor of Compliance

Requirements (Continued)

Overall Quality

Average- 1 2 2 3 2

Comments Records are required in technical assessments, patient dose records,

radiation incident records QA committee meetings.

Do not need clinical protocols and do not have findings from

inspections available. The Act focuses on preparing

reports to ensure accountability, rather

than compliance

Outcomes of non-

compliance

Overall Quality Score

(Sanctions) Act- 1; Code-0; Average-0

2 (violations will result in a loss of

accreditation but no support is offered)

3 (strong penalties such as seizure and revocation of

license, monetary and criminal penalties)

N/A (Not listed for the member states)

4 (License suspensions or revocation= moderate

sanctions, but the support is strong)

(Support offered)

No support offered, but follow up inspections may

be conducted after an initial warning

Offers strong support from the medical bodies when institution is non-

compliant

Comments There are no penalties stated in the Code of

Practice, so there is no transparency about how institutions are punished for non-compliance. The Act is more generalized

and only provides moderate violations

Fairness

Criterion 1 (Equitable language)

Act-4; Code-4 4 4 4 4

Page 249: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

228

Domain Criterion Australia BC1 California Euratom Germany

Fairness (continued)

Criterion 2 (Accounts for all institutions

types and workflows)

Act-N/A; Code-0

3 (The accreditation standards distinguish

the governance structure for large

networks vs. smaller hospitals and it allows for some roles to be

combined)

0 (All facilities are expected to abide by the Act, without

distinction for institution type)

0 (All member states must comply,

regardless of its economic or social

states)

2 (All institutions are assumed to be the same, but the medical bodies

offer a means of helping the smaller institutions)

Overall Quality

2 4 2 2 3

Comments The Act is written for all

users, regardless of type. It does not show a preference for any

institutions.

The fairness and rigor of compliance can be

linked to the lawsuit by the European

Commission against select countries.

1 Only the mandatory requirements from the BC DAP Accreditation Standards were assessed in Part 2 of RACT 2 for legislation quality

2 All of the documents that were analyzed are readily available for the public through search on the internet. The information that is being assessed

for accessibility are the records and results of the CT facilities.

Page 250: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

229

Table F- 2: The detailed legislation quality assessments for Ireland, India, Kenya and Ontario. The comments provide explanations of the assigned domain scores. The legislation

documents highlighted with red font in Table 5 were analyzed for the legislation assessment.

Domain Criterion Ireland India Kenya Ontario

Clarity and Presentation of Legislative

Scope

Criterion 1 (Definition of

scope and language)

4 (Medical exposure is clearly defined by the scope)

2 (Broadly stated to include all radiation sources)

2 (Broadly defined as to protect the public and

workers from the dangers arising from the use of

devices producing ionizing radiation)

0 (There is no scope in the Act and Regulations)

Criterion 2 (Writing style)

4 (the vocabulary is very straightforward and easy to

understand)

4 (Written with simple vocabulary, making it easy to understand by

general public and targeted users)

3 (Written with simple vocabulary that is easy to

understand, but some of the offences are written in legal

jargon)

4 (The writing is easy to understand and written with

no specific jargon)

Overall Quality

4 3 2 2

Comments

Transparency

Criterion 1 (Description of

processes)

2 (The requirements for processes are stated as a command, but minimal

guidance is provided for most processes. Some are well

defined such as formation of the radiation safety committee,

but it does not state the responsibilities and duties in

specific )

1 (Processes are stated as commands, so most required

processes are not stated in detail and no guidance are provided. For example, ensure that QA tests are

conducted or carry out routine measurements on radiation and

make records, but no specific tests are detailed)

2 (There are not many processes noted in the

legislation, but the available ones are mostly well-defined.

For example, the issued licenses shall be in a specified

format. However, there remains some "command" type requirements that do

not have guidance)

3 (Although there are not many processes included in the Act and regulations, the

ones that are do have sufficient detail. For example,

the barriers design and shielding requirements. But

there are also some reporting details that are lacking)

Criterion 21 (Accessibility

of information)

0 (not sure if the records collected can be requested by

the public or target users)

0 (No mention of how to find information of licensed facilities

and machines)

0 (no mention of how the general public can get the

information regarding registered machines)

0 (no mention of how to access information, or if

information can be assessed by the general public)

Overall Quality

1 1 1 1

Comments

Page 251: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

230

Domain Criterion Ireland India Kenya Ontario

Accountability (continued)

Criterion 1 (Description of

responsible authority,

punishable actions and

enforcement procedures)

2 (The enforcement procedure such as appeal process and so

forth are not defined)

1 (Punishable actions and enforcement procedures are not

well-defined; very ambiguous) 3

4 (Very well-defined enforcement procedure)

Criterion 2 (Horizontal

accountability) 3 (reporting requirements

between the advisory board, and the competent authority-

not detailed examples, but mentioned)

0 (No mention of horizontal accountability; no peer review program; only one competent

authority available)

2 (There are different members that are required to be on the radiation advisory

boards; suggestive of wanting accountability and fair

representation; the bard also advises the Minister; no peer

review programs)

0 (No mention of different responsible authorities; no

peer review programs required)

Criterion 3 (Vertical

accountability)

2 (There are requirements for written inventory, and other

records, but no explicit mention of the competent authority checking these

records)

1 (There are some requirements for vertical accountability from the

institution to the competent authority, but the

1 (There are mention of records that need to be kept

such as exposure records, but they are not very detailed

and there is no defined submission of reports to

authority)

2 (Inspections, and records; there are reporting

requirements and the inspectors are required to tell

the competent authority of non-compliance)

Overall Quality

2 1 2 3

Comments

Rigor of Compliance

Requirements

Criterion 1 (Burden of evidence)

2 (Requires standard protocols, inventory lists, patient dose records, NO qualification of

staff, NO radiation incidents…but not really sure if these are checked before you

get compliance)

1 (Evidence requirements and records are listed as responsibilities

of individual staff roles

1 (Some mention of exposure records, no inventory lists, no

qualification lists etc.)

1 (Inventory lists, work done, radiation incident)

Page 252: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

231

Domain Criterion Ireland India Kenya Ontario

Rigor of Compliance

Requirements (continued)

Criterion 2 (Compliance monitoring)

2 (The medical council is supposed to set up the audit

system, but no mention of the actual system structure; there is review of the doses by the

health boards)

1 (There is an option for the competent authority to appoint agencies to check compliance)

1 (Compliance checks are mentioned as a possibility for the chief radiation protection

officer that is appointed)

2 (no scheduled frequency, but may enter at all reasonable times)

Overall Quality

2 1 1 1

Comments

Outcomes of non-

compliance

Overall Quality

(Sanctions) 2 (The sanctions are mainly fines and some civil penalties)

1 (no support is offered and the only mentioned possible sanction is

the suspension or revocation of license)

3 (License revocations, and criminal penalties/monetary

fines)

3 (Severe sanctions including criminal penalties and monetary penalties;

revocation of licenses)

(Support offered)

(Support or guidance notes are offered by the radiation

advisory committee set up) NO support offered

Comments

Fairness

Criterion 1 (Equitable language)

4 4 4 4

Criterion 2 (Accounts for all institutions

types and workflows)

2 (The health boards are expected to form advisory

boards for QA, but holders of individual machines are also

able to form QA committees if desired)

0 (No mention of different institution types)

0 (No distinguishing between institution types)

1 (All institutions must fulfill the requirements, but they did take into account the

different facility types that may have an x-ray machine)

Overall Quality

3 2 2 2

Comments

1 All of the documents that were analyzed are readily available for the public through search on the internet. The information that is being assessed

for accessibility are the records and results of the CT facilities.

Page 253: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

232

Table F- 3: Legislation quality was assessed for Portugal, Switzerland, Texas and the UK. Comments provide explanations for the domain scores. The legislation documents

highlighted with red font in Table 5 were analyzed for the legislation assessment.

Domain Criterion Portugal Switzerland Texas UK

Clarity and Presentation of Legislative

Scope

Criterion 1 (Definition of

scope and language)

4 (Each Decree Law has a subject and scope that establishes what

is incorporated into the act)

4 (Lists all the machines that are included, as well as

mentions the ones that are exempt)

4 (Each section has purpose and scope listed for what is

included)

4 (Clearly outlines what each document is about, including which articles are for medical

exposures)

Criterion 2 (Writing style)

3 (Some of the writing is difficult to understand. For example, the structure and purpose of each

Commission. Some of this could be due to the use of a translator)

4 (Easy to understand vocabulary and writing style)

2 (The section code for the ionizing radiation

generators is clear; however, the Texas

Radiation Control Act is filled with legal jargon)

4 (Very easy to understand vocabulary and easy to

understand writing style)

Overall Quality 3 4 3 4

Comments

Transparency

Criterion 1 (Description of

processes)

3 (Some processes require further clarifications. For

example, the responsibilities of individual staff members and how to fulfill them. However,

other procedures like optimization and justification are provided with ample guidance)

3 (Some processes require more guidance on how to

accomplish it, but most processes have ample guidance

such as the information that needs to go into the registry)

3 (The processes that are included in the act are

detailed and offers guidance as to how to achieve compliance)

3 (Exercises the duties of staff roles as "commands" and

expects certain procedures to be accomplished, with

minimal guidance, but other processes have more detail

such as justification)

Criterion 2 (Accessibility of

information) 2 (Signs that show the licensing

and the accountable person must be put on the door; but there is no mention if this information is

available for users)

4 (The Federal Commission for Radiological Protection is

responsible for informing the public about the radiological protection situation regularly and it provides advice on a list

of matters )

3 (Any information about any facility can be

systematically requested by the general public)

0 (no mention of accessing information by the public or

target users)

Overall Quality 3 4 3 2

Accountability

Criterion 1 (Description of

responsible authority,

punishable actions and

enforcement procedures)

4 (The responsible authority, and enforcement actions for offences

are well defined)

4 (Everything listed here is available and in detail)

4 (All are explained in detail)

IR1999-4, IRmeR2002-2; average 2 (The IR(ME)R does

not have any enforcement procedures or offences, but the authority is listed in its

list. The enforcement procedures and actions for IR

1999 are not correlated properly)

Page 254: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

233

Domain Criterion Portugal Switzerland Texas UK

Accountability (continued)

Criterion 2 (Horizontal

accountability) 3 (The CTN and CVT monitor each other and the complaints of the

general public)

3 (There is room for collaboration and consultation between the commissions for

join tasks in the field of radiological protection; may

engage external parties; inter-comparison measurements for

some facilities may be required)

3 (Advisory board evaluates and reviews state

programs, but one agency is involved in the

monitoring and compliance of individual institutions)

2 (External consultation of radiation protection advisers are required; No mention of peer review, or collaboration

between different organizational bodies)

Criterion 3 (Vertical

accountability) 3 (Book of complaints is required

by the facilities, and monthly reports are sent to the Ministry of Health; the commissions are

also expected to advise the Ministry)

4 (The federal commission is required to make regular

reports that are required for the public; the license holders are also required to report to the cantonal authorities and

supervisory authorities)

4 (Radiation committees at each institution must

report to the responsible authority and disclose what is going on at each facility;

other records are also reviewed by the

authorities)

3 (The institutions must report to the competent

authority periodically)

Overall Quality 3 4 4 2

Comments

Rigor of Compliance

Requirements

Criterion 1 (Burden of evidence)

3 (Inventory list, standard protocols, qualifications list,

radiation incident, Logs are to be submitted with equipment and

other tests annually, NO QA documentation)

3 (Registry, inventory lists, QA documentation, qualification of

staff; NO clinical protocols)

4 (Dose records, QA, qualifications, inventory, testing records, radiation

incident, protocols)

2 (inventory lists, protocols, qualifications of staff, QA

committee records= minimal)

Criterion 2 (Compliance monitoring)

2 (Checks are required to be established for a specified period

stated by the Ministry, but no frequency is specified)

2 (Spot checks may be carried out regularly)

4 (Records of surveys are required and internal audits

must be performed periodically; 2 year for CT

inspections)

0 (There is mention of an internal clinical audit system. No mention of surveys done

by official authority)

Overall Quality 3 3 4 1

Comments

Outcomes of non-

compliance

Overall Quality (Sanctions)

3 (Strong sanctions such as seizure of equipment or closure

of facility; criminal and monetary penalties)

4 (There are criminal and monetary penalties as well as license violations can lead to

revocation)

3 (Violations will results in severe sanctions)

2 (Only mention of revocation of license; no mention of criminal or monetary penalties)

Page 255: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

234

Domain Criterion Portugal Switzerland Texas UK

Outcomes of non-

compliance (continued)

(Support offered) NO support offered by the government

The Federal Commission offers support and guidance.

NO support given

Comments

Fairness

Criterion 1 (Equitable language)

1 (There is a specific decree law for facilities that are private and

for profit with CT scanners) 4 4 4

Criterion 2 (Accounts for all institutions types and workflows)

0 (The Euratom Directive transposition, however, assumes only one type of facility and every

facility must meet the requirements)

0 (All facilities are put through the same requirements)

3 (Provides an option for smaller facilities to bind

together to form the RPCs)

0 (All facilities must achieve the requirements set out in

the documents)

Overall Quality 1 2 4 2

Comments

Page 256: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

235

Part 3: Supplemental Document Quality Assessment

Table F- 4: The quality assessment for supplemental document from Australia, BC, California and Canada. The comments provide explanation of the assigned score, and the

documents analyzed are highlighted in green in Table 5

Domain Criterion Australia BC1 California2 Canada3

Clarity of Scope and Purpose

Criterion 1 (Definition of goal, target problem, population and practice setting)

4 (goal: advice on good radiation practice and

guidance; health problem is radiation protection; target

population is medical exposure and the practice setting is diagnostic and interventional radiology)

3 (Goal of DAP; target problem not specific; target population

all facilities and appropriate setting= all facilities)

JC: 0; IAC: 2; ACR: 2 (IAC and ACR talk about which types of

facilities it is targeted towards, and the target population.

However, JC's is implicit called "diagnostic imaging services

revised requirements". IAC and ACR offer more detail about the

structure)

4 (explains very clearly what is within the

document, and why it is important)

Criterion 2 (Rationale for developing) 4 (Foreword explains the

reason for the development of the safety guide)

3 (Does not really target the radiation protection problem.

Focuses on the importance of a diagnostic accreditation

program for all diagnostic activities)

IAC: 3; JC: 0; ACR: 0 (JC and ACR do not go into the development

of the document or why it's developed. IAC talks about the

purpose of the revisions and the program)

4 (gives a very good explanation of the reason

for development; and specifies its importance in

guidance)

Criterion 3 (Writing style and vocabulary)

4 (writing uses simple vocabulary and easy to

understand writing style)

4 (written with minimal technical terms)

JC: 2; IAC: 3; ACR:3 (ACR uses many acronyms that may be

confusing for general public, JC uses more technical (legal

jargon), IAC provides easy to understand writing)

3 (There are some technical terms with the specific x-

ray equipment terminology)

Overall Quality 4 3 2 4

Evidence support and explanation

for processes and recommendations

Criterion 1 (Evidence from literature and explanations)

3 (Most explanations are supported with a peer-reviewed publication to

provide further guidance)

4 (Each part of the standards has a "reviewed documents"

and a "specific documents referenced" section. Refers to

other credible sources)

JC: 0; IAC: 4; ACR: 0 (JC and ACR references other pages of its own

standard, no explanations are provided; IAC cites best practice

expectations)

4 (Each of the recommendations normally

refer to other standards)

Criterion 2 (Cost-benefit analysis for recommended practices)

3 (Limitations and costs are only provided for some processes; benefits are

implicit in the recommended action(

3 (Most processes that are checked have an "introduction"

section that explains the benefits of the section. Costs of recommended actions are less

likely to appear)

0 (Provides requirements that must be fulfilled but does not

explain why it is recommended)

4 (The benefits and costs for the quality assurance

committee is very detailed; the other recommended

actions have introductions to explain the rationale)

Overall Quality 3 4 1 4

Page 257: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

236

Domain Criterion Australia BC1 California2 Canada3

Instructive quality of writing

Criterion 1 (Description of procedures)

3 (Most of the recommended actions are explained in detail, with guidance to

execute. However, some other requirements just

simply ask the employers and responsible persons to

request the guidance of experts)

3 (Most recommended actions have sufficient detail to reach

compliance with the standards. However, additional guidance can be offered for some. For

example, how to establish local DRLs.)

ACR: 3; IAC:4; JC:1 (IAC provides enough details to achieve compliance; JC lists more

expectations--remember that JC is not actual standards, just a

republication requirements; ACR responsibilities for different roles are not explicit instructions-more

like expectations)

4 (Very clear instructions provided)

Criterion 2 (accessibility of the document)

4 (The document is easily found)

4 (The accreditation standards can be easily found)

2 (The standards must be purchased, cannot access full

copies) 4 (Easily found document)

Overall Quality 3 3 2 4

Adaptability

Criterion 1 (Consideration for different institution types and clinical workflows)

3 (Offers alternative options for most of the

recommended actions. For example, if an older machine

is used, other options are provided to achieve

compliance)

4 (Offers alternative options based on hospital/health region size. There are also alternatives

based on the age of the equipment)

JC: 2; IAC: 1; ACR: 3 (JC looks at the hospital type- critical vs. ambulatory care center; IAC

provides different options for the qualification fulfillment; ACR

looks at the number of modules that a hospital is applying for, but

still has an "all" facilities requirement)

2 (Only offers some indication for smaller

hospital sizes and for some procedures)

Integration of inter-professional

perspectives

Criterion 1 (Description of CT stakeholder roles)

4 (Responsible person, referrer, operator, radiation

medical practitioner. Radiation safety officer,

medical physicist, and EVEN other professional groups that MAY have exposures

such as nurses!)

4 (Responsible person, referrer, operator, radiation medical

practitioner. Radiation safety officer, medical physicist, and

EVEN other professional groups that MAY have exposures such

as nurses!)

JC: 1 (Just medical physicists; IAC & ACR: 3 (practitioner, directors,

medical staff, technologists, support services for IAC)

3 (Does not talk about qualifications of the actual

radiologist)

Criterion 2 (Definition of each stakeholder group’s qualification requirements, responsibilities and functions)

3 (Each group's requirements, responsibilities and functions are defined, but some of the

training that needs to be received are not explicitly

stated)

4 (Dedicated accreditation sections to the human

resources and medical staff)

IAC and ACR: 4 (very detailed qualification options and

responsibilities); JC: 4 (for the medical physicist that is

mentioned)

3 (The recognized stakeholders were defined

and their roles were detailed)

Page 258: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

237

Domain Criterion Australia BC1 California2 Canada3

Criterion 3 (Peer-review of the document)

4 (The foreword explain the oversight of the development

of the document. It also offers additional information if requested from the public)

0 (The standards reference other documents that were

reviewed, but there is no specified peer review process)

0 (no mention of a peer review process; written as a standards document that must be fulfilled by each respective organization)

4 (The acknowledgements section explains who was

involved in the preparation of the document and made

suggestions)

Overall Quality 4 3 3 3

Rigor of expectations

Overall Quality (Amount of work required to meet

recommended action plans)

3 (Most recommended workflows are described in

the safety guide)

2 (Do not have requirements regarding DRLs, and detailed QA assessments or radiation

incidents)

JC: 2; IAC and ACR:3 (no DRL establishments in any of them,

no peer review requirements for JC)

2 (Mostly focused around the technical standards,

DRLs and some mention of quality assurance but QA was focused on technical

maintenance)

Rigor of Updates

Criterion 1 (Explanation to validate information)

4 (The foreword explains the information included in the

document

2 (The information is cited with "recent" publications)

IAC and JC: 2 (notes how they updated it recently for the new

standards) ACR: 0 (No mention of updates for the new standards or

the validity of the information)

3 (the information was mostly validated by the

reference to other standards)

Criterion 2 (Description of plan for updates and expected frequency of updates)

3 (Foreword states that the expected review and update is in 2 years, but document

was adopted in 2008, and it is the latest version in 2015)

0 (Only accreditation cycle frequencies, but does not

explain the actual update plans for the document itself)

ACR: 2 (Notes revisions to the standards); JC: 3 (noted the

recent update) IAC:3 (made a recent revision)

0 (no description of plans to update safety code)

Overall Quality 3 1 3 2

1 British Columbia’s DAP accreditation standards were used for the supplemental document quality assessment as well. Only the non-mandatory requirements were assessed as “supplement” materials. 2 California CT facilities have a choice of three accreditation programs: ACR- American College of Radiology; IAC-Intersocietal Accreditation Commission; JC- Joint Commission 3 Canada was analyzed as a separate jurisdiction because the parts of Safety Code 35 that were deemed pertinent to BC standards were extracted and put into the BC DAP accreditation document. The other Canadian province available in the analysis, Ontario, does not provide access or recommend the Safety Code 35 and so, Safety Code 35 was not considered as a resource for Ontario facilities.

Page 259: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

238

Table F- 5: The supplemental document quality assessment for IAEA, Ireland, India and the UK. Explanations for the assigned scores are provided. The documents that were used

in this analysis are highlighted in green in Table 5

Domain Criterion IAEA Ireland India UK

Clarity of Scope and Purpose

Criterion 1 (Definition of goal, target problem, population and practice setting)

4 (Goal: provide safety guidance that each member state should meet,

target health problem: use of ionizing radiation; population: member states;

practice setting: any medical facility with the radiation equipment)

3 (Goal is defined, and the target population/setting.

However, the problem that requires the establishment

of DRLs is not explained)

4 (Gives good background to the problem, the goal,

target population and practice setting)

3 (Everything is explained really well except the target

health problem is not detailed)

Criterion 2 (Rationale for developing)

4 (Foreword explains why the safety standards were developed overall by IAEA, and introduction explains the growing use of ionizing radiation)

3 (Explains why it was developed, but not how it

was developed)

3 (The foreword explains why it was developed at

the INMAS, but not really how)

3 (The development of the document is explained in terms of a goal, but the

different opinions included are less explicit comparatively)

Criterion 3 (Writing style and vocabulary)

4 (Simple vocabulary, minimal technical jargon)

4 (Simple vocabulary; equations were exempted from this because they use technical radiation output

measurements)

4 (Simple vocabulary and written with easy to

understand style)

4 (Simple vocabulary; easy to understand writing style)

Overall Quality 4 3 4 3

Evidence support and explanation for

processes and recommendations

Criterion 1 (Evidence from literature and explanations)

4 (Processes are supported with literature. Explanations are also

provided to detail the purpose of the recommended action)

4 (provides evidence to the establishment of DRLs)

2 (Minimal evidence used to support recommended

action plans)

4 (Cited with a lot of peer reviewed articles)

Criterion 2 (Cost-benefit analysis for recommended practices)

1 (Benefits and costs are not explained for the recommended actions. It just

specifies requirements as "good practice" and requires compliance)

0 (Written for just establishment of DRLs, and written as what SHOULD be

done without offering explanations for why)

1 (Does not explain the benefits and costs of most recommended actions. Written in

statement "command" form)

1 (Minimal benefits and costs are offered for the

recommended actions)

Overall Quality 3 2 2 3

Instructive quality of writing

Criterion 1 (Description of procedures)

3 (The recommended procedures are offered in detail and explains what the minimal compliance thresholds should

be for member states)

4 (Very detailed review of literature to show how

DRLs should be established)

2 (The responsibilities of the RSO that need to be fulfilled are very vague. No guidance is provided

on how to achieve compliance)

3 (Provides guidance as to what should be established,

but allows for some flexibility depending on the structure of the facility; offers other

resources that may be used)

Page 260: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

239

Domain Criterion IAEA Ireland India UK

Instructive quality of writing (continued)

Criterion 2 (accessibility of the document)

4 (Information is readily accessible by the public)

3 (Paper appears to be slightly hard to come by, as

links to it are no longer working- may be due to a change in the structure of the radiation protection

objective)

4 (information can be easily found)

4 (Easily found on the website)

Overall Quality 4 3 3 3

Adaptability

Criterion 1 (Consideration for different institution types and clinical workflows)

4 (The standards take into account the different economic and social statuses o each country to provide alternative

options that may be less costly, but still acceptable)

2 (Provides explanation for different radiation output measurements that can be

used when establishing DRLs. However, it does not suggest how to do it if you

are a smaller facility. Assumes same size

operation and resources)

0 (Assumes only one set of possible conditions and sets the standards to be the same for everyone, regardless of size and

economic level)

1 (Requires all the facilities to reach the same

requirements, however, requirements are set loosely i.e. establish a QA program;

also addresses situations where there may be more

than one employer that shares a machine= different

operation condition)

Integration of inter-professional perspectives

Criterion 1 (Description of CT stakeholder roles)

4 (The common radiation team roles are mentioned such as operators,

practitioners, referrers and physicists)

0 (Does not mention the stakeholders in the

optimization process)

1 (Only Director, RSO and the radiation workers are

grouped together)

2 (Practitioner, physicist, RPA, director/licensee)

Criterion 2 ( Definition of each stakeholder group’s qualification requirements, responsibilities and functions)

2 (Does an excellent job defining the roles of each stakeholder's role and

responsibilities. However, the nature of the guidance document does not allow

for specific qualifications since this varies between member states)

0 (No mention of stakeholder groups)

2 (The functions and responsibilities of the

roles are listed; the qualifications are listed mainly for the RSO; less clear for the radiation

workers)

2 (The qualifications are not listed, and the roles are not explicitly listed, but it names the responsible person for

each recommended action)

Criterion 3 (Peer-review of the document)

4 (Foreword explains the review of all member states for comment before

approval by IAEA board)

0 (No external review of the document; written as the

position of the medical council)

0 (No peer review process is described)

0 (no mention of a peer review process; written as a guidance document by the

HSE, but mentions the peer-reviewed sources that were

used)

Overall Quality 4 0 1 1

Page 261: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

240

Domain Criterion IAEA Ireland India UK

Rigor of expectations

Overall Quality (Amount of

work required to meet

recommended action plans)

4 (Explains the commonly recommended processes, and requires them to be added to member states'

regulations)

2 (DRLs are labour intensive and should be updated. The position paper encourages establishment of local data

for DRLs)

1 (Does not focus on optimization and

justification as much, but still addresses the idea of

quality assurance)

2 (no mention of DRL establishments, focuses on

the equipment aspect, which is the objective of the notes; talks about a QA program)

Rigor of Updates

Criterion 1 (Explanation to validate information)

4 (the foreword explains who is involved, who sponsored it, who reviewed it, and how it has been

written with recommendations from peer-reviewed literature)

2 (References the ICRP's position and assumes it is

valid)

1(No clear explanation offered in terms of the

validity of the document, except its relation to the

ICRP)

0 (Does not validate the information; just provides the

view of the responsible authority and lays down an

iron hand)

Criterion 2 (Description of plan for updates and expected frequency of updates)

0 (no mention of update plans or how often new reports are published)

1 (Explains the need to update the levels, but does not provide an actual plan)

2 (Describes planned updates in accordance

with the knowledge evolution of the ICRP)

3(The guidance document for equipment is on the third edition-first published in

2006, so it's about 3 years per edition)

Overall Quality 2 1 1 2

Page 262: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

241

Appendix G: Official DRL Comparisons in CTDIvol

The graphs in this section provide a comparison of the official DRL values in volume CT dose index

measurements. These values are corresponding to the reported DLP values in Section 6.2.1.

Figure G- 1: Official DRL values for each jurisdiction’s head-related CT exams. The CTDIvol DRLs are comparable for all of the

jurisdictions. [128], [129], [130], [131], [132]

Figure G- 2: A graphical display to compare the face-related DRL values expressed in volume CT dose index. Germany's official

DRL value for sinusitis is visibly lower compared to the other jurisdictions' values. [129], [130], [131]

Figure G- 3: A comparison of the official DRL values in the volume CT dose index measurement for neck-related exams. [128], [130], [132]

65

60

65 65

60 60

57

58

59

60

61

62

63

64

65

66

Germany, Skull/Brain Australia, Head Switzerland,Skull/brain

Switzerland, brain(vascular)

Ireland, routine head UK, brain (whole)

CTD

I vo

l (m

Gy)

Head-related Exam Type (Country, Exam Type)

22

9

25

35

0

5

10

15

20

25

30

35

40

Germany, Facial (tumourdiagnostics)

Germany, Facial (sinusitis ) Switzerland, Sinus Ireland, Face and sinuses

CTD

I vo

l (m

Gy)

Face-related Exam Type (Country, Exam Type)

30

20

3028

0

5

10

15

20

25

30

35

Australia, Neck Switzerland, Neck Switzerland, Cervical spine UK, cervical spine

CTD

I vo

l (m

Gy)

Neck-related Exam Type (Country, Exam Type)

Page 263: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

242

Figure G- 4: A comparison of the official DRL values for chest-related exams. Switzerland's CTDIvol value for the general thorax

scan is comparatively lower. [128], [129], [130], [131], [132]

Figure G- 5: A graphic display of the official DRL values for abdomen-related examinations. The first three bars are the

comparative values for upper abdomen examinations, while the latter three bars are for routine abdomen examinations. [129], [130], [131], [132]

Figure G- 6: The official DRL comparisons for pelvis-related examinations. Ireland's routine pelvis DRL value in CTDIVOL is

notably higher. [129], [130], [131]

1215

10

15

3028

0

5

10

15

20

25

30

35

Germany, thorax Australia, chest Switzerland, thorax Switzerland, thorax(vascular)

Ireland, chest UK, chest (lung cancer)

CTD

I vo

l (m

Gy)

Chest-related Exam Type (Country, Exam Type)

25

15

20 20

35

14

0

5

10

15

20

25

30

35

40

Ireland, liver andspleen

Switzerland, upperabdomen

Germany, upperabdomen

Germany, abdomen Ireland, routineabdomen

UK, abdomen (livermetastases)

CTD

I vo

l (m

Gy)

Abdomen-related Exam Type (Country, Exam Type)

20 20

35

0

5

10

15

20

25

30

35

40

Germany, pelvis Switzerland, pelvis Ireland, routine pelvis

CTD

I vo

l (m

Gy)

Pelvis-related Exam Type (Country, Exam Type)

Page 264: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

243

Figure G- 7: A comparison of trunk-related DRL values for the jurisdictions with official DRLs. The first three bars are the

CTDIvol measurements proposed as the official DRL for abdo-pelvis exams, while the latter three bars indicate the official

CTDIvol DRL value for chest-abdo-pelvis exams.

Figure G- 8: A comparison of the official DRL values in volume CT dose index measurements for lumbar-spine related

examinations. Germany's exams are divided into specialized exam types.

15 15 15

30

15

0

5

10

15

20

25

30

35

Australia, abdo-pelvis Switzerland, abdo-pelvis UK, abdo-pelvis (abcess) Australia, chest-abdo-pelvis

Switzerland, thorax-abdo-pelvis

CTD

I vo

l (m

Gy)

Trunk-related Exam Type (Country, Exam Type)

42

16

40

30

0

5

10

15

20

25

30

35

40

45

Germany, lumbar spine(intervertebral disc axially)

Germany, lumbar spine (bone-spiral)

Australia, lumbar spine Switzerland, lumbar spine

CTD

I vo

l (m

Gy)

Lumbar-related Exam Type (Country, Exam Type)

Page 265: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

244

Appendix H: Comparison of Percentage Fulfillment of each

Theme

Table H- 1: A comparison of the average percentage fulfillment of each theme between the "strong" jurisdictions and all

jurisdictions. Kenya, who had systematically higher proposed DRL values, is representative of a "weak" jurisdiction.

Theme Average of all jurisdictions

Average of strong jurisdictions

Kenya (weak jurisdiction

average)

General Provisions 58.33% 57.14% 57.14%

Responsible Authorities 26.13% 26.13% 18.92%

Licensing and Accreditation 36.78% 32.18% 55.17%

Technical Requirements 31.67% 30.95% 0.00%

Facility Requirements 34.38% 32.29% 43.75%

Operational Requirements 26.43% 27.14% 12.86%

Personnel Requirements 30.75% 32.14% 16.67%

Radiation Protection/Quality Assurance Committee

23.86% 30.30% 4.55%

Patient Records and Patient Medical Reports

20.45% 22.73% 9.09%

Emergency Situations and Event Reporting

28.89% 22.22% 0.00%

Diagnostic Reference Levels 20.56% 27.78% 0.00%

Results of non-compliance 26.81% 26.09% 30.43%

Page 266: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

245

Appendix I: Definitions of Clinical Justification for Medical

Exposure

Kenya’s standards for clinical justification of medical exposures found in “Subsidiary

Legislation- Radiation Protection (Standards) Regulations, 1986 [L.N. 54/1986]” [164]

13. Medical Exposure

1) Medical exposure is the intentional exposure of patients for diagnostic and therapeutic

purposes under the supervision of authorized medical personnel, and the exposure

resulting from the artificial replacement of body organs or functions

2) No dose equivalent limits are set for medical exposure, but medical personnel should

adhere to the basic principles in radiation protection of the patient, that is—

a) unnecessary exposures should be avoided;

b) necessary exposures should be justifiable in terms of benefits that would not

otherwise have been received;

c) the dose actually administered should be limited to the minimum amount

consistent with the medical benefit to the individual patient.

Council Directive 97/43/Euratom’s recommended standards for clinical justification

of medical exposures [68]

Article 3: Justification

1. Medical exposure referred to in Article 1 (2)a shall show a sufficient net benefit, weighing the

total potential diagnostic or therapeutic benefits it produces, including the direct health benefits to

an individual and the benefits to society, against the individual detriment that the exposure might

cause, taking into account the efficacy, benefits and risks of available alternative techniques

having the same objective but involving no or less exposure to ionizing radiation.

In particular:

a) All new types of practices involving medical exposure shall be justified in advance

before being generally adopted,

Existing types of practices involving medical exposure may be reviewed whenever new,

important evidence about their efficacy or consequences is acquired.

b) All individual medical exposures shall be justified in advance taking into account

the specific objectives of the exposure and the characteristics of the individual

involved.

If a type of practice involving a medical exposure is not justified in general, a

specific individual exposure of this type could be justified in special circumstances,

to be evaluated on a case-by-case basis.

Page 267: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

246

The prescriber and the practitioner as specified by Member States, shall seek,

where practicable, to obtain previous diagnostic information or medical records

relevant to the planned exposure and consider these data to avoid unnecessary

exposure.

c) Medical exposure for biomedical and medical research shall be examined by an ethics

committee, set up in accordance with national procedures and/or by the competent

authorities.

d) Special attention shall be given to the justification of those medical exposures where

there is no direct health benefit for the person undergoing the exposure and especially for

those exposures on medico-legal grounds.

2. Exposure referred to in Article 1 (3)a shall show a sufficient net benefit, taking into account also

the direct health benefits to a patient, the benefits to individuals referred to in Article 1 (3) and the

detriment that the exposure might cause.

3. If an exposure cannot be justified, it should be prohibited.

a Article 1(2): This Directive shall apply to the following medical exposure:

(a) the exposure of patients as part of their own medical diagnosis or treatment;

(b) the exposure of individuals as part of occupational health surveillance;

(c) the exposure of individuals as part of health screening programmes;

(d) the exposure of healthy individuals or patients voluntarily participating in medical or

biomedical, diagnostic or therapeutic, research programmes;

(e) the exposure of individuals as part of medico-legal procedures. b Article 1(3): This Directive shall also apply to exposure of individuals knowingly and willingly helping

(other than as part of their occupation) in the support and comfort of individuals undergoing medical

exposure.

Page 268: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

247

Appendix J: Sample Questions for Radiologists

The study team will ask for information regarding the following topics: 1. Awareness of cancer risk and CT radiation dose correlation 2. Needs and priorities in CT imaging (i.e. sharp image, patient safety, time effectiveness)

a. Decision making process for scan area, radiation dose, scan length etc. 3. Perceived availability and ease of use of radiation dose minimization tools

a. Technologies b. Institutional policies

4. Potential solutions that may be useful to ensuring adherence to ALARA principle a. Concerns regarding potential changes in technology and/or protocol b. Reasons for potential resistance

Sample questions to establish an overview of awareness for the correlation between cancer risk and CT radiation dose

Are you aware of the health risks associated with CT? o Do you advise patients of these risks before each scan?

What is your perception of the cancer risks associated with CT scans? o Do you think it is a serious concern? o Do you think the benefits outweigh the risks for diagnostic imaging? o Do you ensure that there is a clinical need for a CT before administering the CT

scan? o If a patient had a referral for a CT scan, but the clinical application does not

indicate the need for a CT scan. What would you do? Sample questions to establish an overview of the needs and priorities of each stakeholder in diagnostic CT imaging

What is the most important factor to consider before the administration of a CT scan?

For radiologists: o What do you require from CT images (i.e. sharp image, high resolution, good

scan coverage etc.)? o How do you balance the use of radiation in your protocols with your needs for

each image? o Do you have any personal preferences/requests to ensure that you get the

image you need when diagnosing a patient?

Sample questions to learn about the available tools currently in place to minimize radiation exposure during CT scans

What are some technologies that you are currently using at your institution to reduce radiation exposure?

o Do you think they are useful? o Are they easy to use and incorporate into your protocols/scanning process? o Do they affect the image quality?

Page 269: The Formulation of a Comprehensive Strategy for Computed … · 2015-11-29 · The Formulation of a Comprehensive Strategy for Computed Tomography Radiation Dose Optimization in Ontario

248

Have you noticed a different in CT radiation education and scanning workflows over the last decade as newer technologies become available?

o Are these new technologies efficient?

Does your institution have guidelines or policies in place to minimize radiation exposure during CT scans?

o Describe these guidelines. o Are they useful? o Do you consciously follow these guidelines when administering CT scans?

Sample questions to identify gaps and potential solutions

What do you think is required for all institutions to comply with the “as low as reasonably achievable” (ALARA) approach for all patient CT scans?

o What do you think is the biggest barrier to making the required improvements to the system?

How can the current radiation protection system for CT be improved? For example, o Should there be a more rigorous compliance standard? Should monitoring be

performed by a committee or task force within the government? Is more education required to understand the vastness of the issue?

o Are there tools that you would like to see incorporated into the current workflow of your institution? If yes, please elaborate.

o What do you think is missing from the currently available guidelines or policies?

If there are changes made to the current scanning process, what would be your biggest concern with regards to that?

What are your suggestions to improve currently available tools/policies? o What are some ways to ensure a smooth transition into these changes?