Radiation  SafetyGuidelines  into  Practice

• Bryan  Walker• Manchester  Heart  Centre

NO  CONFLICT  OF  INTEREST  TO  DECLARE

SAFETY  IN  THE  CATH  LAB

• Radiation  safety  has  layers• 1.  ALARP• 2.  Use  dose  saving  equipment• 3.  Inverse  square  law• 4.  Protection• 5.  Monitoring

1.    Keep  radiation  dose  to  patient  As  Low  As  Reasonably  

Practical  (ALARP)

• This  will  reduce  your  dose  too• And  that  of  everyone  else  in  the  lab

2a.  Useful  dose  reducing  features

• The  radiographer• They  can  suggest  dose  saving  features

• Like  reducing  fluoroscopy  pulse  rates

• …  and  frame  rate• (and  remind  you  to  take  your  foot  off  the  pedal)

2b.  Skin  Dose  reduction  in  practice

• Save  our  Skins  working  group• Work  done  in  northwest  cath  labs• Dose  reduction  in  excess  of  50%• 7  sites  involved• Poster  at  entrance  to  main  hall

● The Cardiologist should provide information to the patient about radiation risk within the consent process.● The Cardiac High Dose Flowchart will be displayed in the Cardiac Catheter Lab and staff will refer to it for advice.

● If it is considered prior to a procedure that a skin dose of 3 Gy or greater is likely (e.g. large patients undergoing complex angioplasty procedures), or the patient has had a procedure in the previous week, then the patient should be counselled before the procedure regarding potential risks and side-effects and informed consent be obtained by the clinician dealing with the patient.

● During the procedure if a dose of 5 Gy or above is reached, further imaging should be deferred for 7 days where possible.

● If a patient has received a potential skin dose of greater than 5 Gy (250 Gycm2), the patient should be followed up after 14-21 days. The patient should be provided with an information card post procedure

Imaging protocol optimisation

Save Our SkinsIdentification and follow-up of patients at risk of skin injury from cardiac catheterisation procedures

● May 2007: A physics survey highlights concerns over the level of skin doses reached following certain catheter lab procedures in some NW centres

● August 2007: Following the survey, two NW centres develop an initial skin dose policy based on recommendations of the ICRP

Original policy: patient threshold dose for investigation set at 3 Gy (single or cumulative dose), above which patient to be recalled for skin assessment 10-14 days post procedure

● 2009: Following the patient skin injury, regional Radiation Protection Supervisors involved in PCI met with Medical Physics Expert support from North Western Medical Physics (NWMP) to form High Skin Dose Group.Aim: to step develop the standard policy

● 2009 : revised policy to be used as standard for NW group formulated following further recommendations ● skin injury threshold of 6 Gy was proposed by a local oncologist based on radiotherapy protocols.

● the relationship between skin dose and DAP was determined by NWMP to be approximately 1 Gy skin dose for each 50 Gy.cm2 (5,000 cGy.cm2)

Revised policy: threshold dose for post procedure follow up increased to 5 Gy

● Cumulative doses only to be included if procedure is repeated within 2 weeks and sum of doses > 5 Gy● Time period increased to 14-21 days for follow up appointment● Skin care advice cards for patients introduced after development by the group

● Group continues to meet to discuss and improve implementation of skin dose policy in the North West

History and development

Skin care card

Figure 1. Example of the skin dose card used in the North West

● The Skin Care Card evolved following a series of High Skin Dose Group meetings.● The group decided the best way to track and advise patients who received high doses was by an informational card.

● The card is given to every patient exceeding 150 Gycm2 or the equivalent of 3 Gy. The credit-card sized card is issued in a plastic wallet to be kept by the patient and presented to catheter lab staff if called for further procedures.

● This means that patients having another x-ray procedure within 14 days can have their cumulative dose estimated and, if it is likely to exceed 5 Gy, be advised of the potential risk of skin injury prior to the procedure.

● The patient’s radiation reading is also kept for a period of 2 calendar months in a register at the treating hospital.● The card was designed to be generic so that all hospitals could use it by simply adding the details of the cardiac centre

concerned to the wallet; with a phone number for patients to contact should they notice skin reactions.

● PCI procedures can cause deterministic injury following long fluoroscopy times● 2000: UK PCI procedures becoming more complex in Cardiac Catheter Laboratories

● 2008: High Skin dose effects (>5 Gy) had not yet been reported in the UK from these procedures. Only seen in USA in text books.

● 2008: No specific, structured protocols in place for monitoring or prevention of these effects in patients in UK catheter labs.● 2009: North West UK Hospital receives notification of deterministic effects from a high skin dose (>25 Gy) PCI procedure,

carried out in 2008.

Background

Figure 2. Flowchart for //decision making on patients with high skin dose//

● At the Manchester Royal Infirmary in 2007, a departmental equipment upgrade gave the opportunity to re-evaluate frame rates in routine use.

● An initial drop from 15 to 7.5 frames per second proved difficult in practice for cardiologists and radiographers.

● Over a period of twelve months, the frame rate was gradually lowered from 15 to 10 and then 10 to 7.5 frames per second for PCI procedures.

● Simultaneously, the fluoroscopy pulse rates were reduced from 12 to 7.5 pulses per second.

● Other procedures have also benefitted from similar changes.● Additional benefits have included increasing the lifetime of the X-ray tubes.

Consent and staging

Date 2002-2007 2007 2008 2009 2010

Average DAP (Gy.cm2 35-40 35-40 30-35 20-30 <20

Frame rate (fps) 12-15 15 10 7.5 7.5

Fluoro pulse rate (pps) 15 15 10 7.5 7.5

Field of view (cm) 15 15 15 20(+live zoom)

20(+live zoom)

Table 1. Imaging Protocols adopted by a North West Cardiology Department

●The Skin Care Card evolved following a series of High Skin Dose Group meetings.●The best way to track and advise patients who received high doses ●Given to every patient exceeding 150 Gycm2 or the equivalent of 3 Gy. ●The credit-card sized card in a plastic wallet to be kept by the patient● Presented to catheter lab staff if called for further procedures.●If further procedure within 14 days, decision matrix is used.●The patient’s radiation reading is also kept in a register at the treating hospital.●Generic card but each hospitals adds the site name and a phone number ●Patients contact should they notice skin reaction●Referral then for OPD and dermatologist or plastic surgeon

Skin care card

• Decision  matrix  for  potential  high  skin  dose

3.  Inverse  Square  Law• Standing  a  foot  further  from  patient’s  chest  =  dose  saving

• Use  longer  catheters  (or  extensions)

• Use  an  injection  pump  for  coronaries

• Do  not  approach  patient  during  runs

4  (a)  Protection• What  is  the  lead  equivalence  of  your  gown

• For  first  operators  it  should  be  0.35-­0.5mm  le

• Depending  on  level  of  scatter  encountered

• Everyone  else  at  least  0.25  mm  le• Ensure  annual  safety  screening

4.(b)  Protection  • Always  stand  behind  something  thick• …  or  something  dense• You  will  find  something  appropriate  nearby

-­

5.  Monitoring• Last  month’s  body  dose• Last  year’s  eye  dose• Do  you  wear  your  dosimeters?

• Some  radiation  injuries  are  genetic

So  stay  safeAnd  don’t  be  a  …

Thank  you

• Bryan  Walker  – Manchester  Heart  Centre