DRN NL meeting 10/12/10

Sjirk Boon, PhD

Disclosure: 

employee Philips Healthcare

Dose reference levels

Regulatory ‐ Industry – Medical Physicists – Clinical end users:

Flying in Formation!

Interventional X‐ray: Int Rad, Int Card, Int Surg

• What is special about interventional X‐ray?– Physician  operates machine

– Large dose levels can occur: deterministic effects can be an acceptable side effect of treatment

– Different risk – benefit balance (treatment of stroke, acute coronary blockage etc etc )

– Usage more important than machine for patient dose

– Training

FDA public meeting 30/31 March 2010 

FDA CDRH website

http://www.fda.gov/MedicalDevices/NewsEvents/WorkshopsConferences/ucm201448.htm

MITA Consensus Answers to FDA Questions about Fluoroscopic Equipment

(Considerations for an Interventional Equipment Perspective)

Represented manufacturers‐ Siemens‐ Philips‐ Toshiba‐ Shimadzu‐ GE

IEC 60601-2-43: 2010 (all interventional equipment)• Brief audible signal at initiation of irradiation• Adjustable  threshold  for  visual  warning  when  provided  and  when  exceeding  a threshold value of cumulative reference air kerma• Removable anti‐scatter grid for pediatrics • Storage of the LIH• Additional filtration of 0.1 mm Copper or equivalent available for pediatrics• Radiation dose structured report

IEC 60601-2-54: 2010 (all non interventional equipment)• Removable anti‐scatter grid for pediatrics • Additional filtration of 0.1 mm Copper or equivalent for pediatrics• Note: No Radiation dose structured report will be required

Mid term future – around 2012 - 2013

Should manufacturers set default imaging protocols for CT and fluoroscopic procedures so that they incorporate the ALARA concept (maintaining dose As Low As Reasonably Achievable) and utilize or provide for incorporation of diagnostic reference levels into CT and fluoroscopic devices? If so, why and how? If not, why not?• Appropriate for diagnostic exams to define reference levels• In interventional, the duration of the case is dependent on many factors: disease state; case complexity; patient anatomy; so recommendation to just provide alert based on a user set reference values (refer to A2)• Manufacturers support creation of reference levels by providing Dose Structure Reporting data export • Reference levels for diagnostic and interventional can be set on a Hospital, National or International level based on literature

QUESTION A4

Distribution of DAP (Gy.cm²) for 19 Hospitals for PTCA

Should manufacturers incorporate into CT and fluoroscopic equipment features to ensure that exposure settings, imaging protocols, and metrics of body dose and peak skin dose are displayed to the operator(s) of the equipment and recorded for physician review? If so, why and how? If not, why not?

QUESTION A6

• We already display estimation of cumulative skin dose (IEC 60601-2-43) and cumulative DAP• Regarding the peak skin dose (expected to be localized), the stakeholders (AAPM; SIR; SCAI; ACR; etc) should decide on the importance of a method of reconstruction of the peak skin dose from the basic geometrical data (beam incidences, Source to Image Distance, patient equivalent thickness, actual patient position versus the table position to be determined) • After peak skin dose metrics have been determined, they can be exported using DICOM Dose SR and accumulated per patient in his/her folder

Should manufacturers incorporate features into CT and fluoroscopic equipment to facilitate transmission of technique parameters, imaging protocols, and dose metrics to a patient's imaging record, an electronic health record, or other database? If so, why and how? If not, why not?

QUESTION A7

• For interventional equipment, by means of the DICOM Dose Structured Report which is proposed for interventional equipment manufactured from June 2012 (DAP and air kerma)

• In future, if a universal unit is proposed to accumulate CT and XRAY equipment, it will be accommodated by an update of the DICOM SR Report

What changes should manufacturers make to CT and fluoroscopic devices currently on the market in order to reduce unnecessary patient exposure to ionizing radiation?

QUESTION A12

•It is important to have continuous education of installed base users by requiring a training program to user facilities also after the initial handover (refer to section B)

•Interventional equipment manufactured prior June 2006 and presumably not compliant with US 21 CFR 1020.30/32 shall be upgraded or replaced prior June 2016 according to the 2006 US Regulation

• Upgrade or replace according to features brought by 21CFR 1020.30/32 (2006) and IEC 60601-2-43: 2000 & 2010 and IEC 60601-2-54: 2009 (e.g. DAP) within a typical serviceable product lifecycle • If not upgradeable, replace

• DICOM Dose Structure Report: interventional equipment manufactured generally from 2007 on, would require only a minor upgrade

But what about the time before RDSR is widely adopted ?

• Many initiatives around the world, one example:

Questions ?