QUALITY AND SAFETY IN MEDICAL IMAGING. Thorarin A Bjarnason 1, Daniel Rickey 2, David Koff 3, Helen Chen 4, Marco Carlone 5

Transcription

1 Interior Health QUALITY AND SAFETY IN MEDICAL IMAGING Thorarin A Bjarnason 1, Daniel Rickey 2, David Koff 3, Helen Chen 4, Marco Carlone 5 1 Kelowna, BC, 2 Winnipeg, MB, 3 Hamilton, 4 Waterloo, 5 Toronto, ON 1

2 Conflicts of interest None #COMPASM16 2

3 Learning Objectives The role medical physicists play in the Bonn Call for Action will be described. The concept of Diagnostic Reference Levels will be introduced and put to practical use. Current positions on the Linear Non Threshold Model will be outlined. Canada Safe Imaging will be introduced. #COMPASM16 3

4 Bonn Call for Action The International Conference on Radiation Protection in Medicine: Setting the Scene for the Next Decade IAEA and WHO initiative held in Bonn, Germany Identified actions essential for enhancing radiation protection in medicine #COMPASM16 4

5 Bonn Call For Action Justification 1) Enhance the implementation of the principle of justification IT solutions such as decision support tool Develop criteria of justification for screening of healthy populations #COMPASM16 5

6 Appropriateness Guidelines CAR: ACR: Criteria #COMPASM16 6

7 Bonn Call For Action Optimization 2) Enhance the implementation of the principle of optimization of protection and safety Establish, use, and regularly update of Diagnostic Reference Levels Establish of Quality Assurance programs for medical exposures #COMPASM16 7

8 Diagnostic reference levels #COMPASM16 8

9 Diagnostic reference levels #COMPASM16 9

10 Diagnostic Reference Levels Statement: Your centre/region establishes its own Diagnostic Reference Levels (DRLs). True? False? #COMPASM16 10

11 Diagnostic Reference Levels Statement: Your centre/region establishes its own Diagnostic Reference Levels (DRLs). True? (most sites answered true) False? #COMPASM16 11

12 What is a Diagnostic Reference Level? Frequency DLP (mgy cm) #COMPASM16 12

13 What is a Diagnostic Reference Level? Frequency DLP (mgy cm) #COMPASM16 13

14 What is a Diagnostic Reference Level? Frequency DLP (mgy cm) #COMPASM16 14

15 Box Plot The 25 th percentile is the value where 25 % of the data fall below it The 75 th percentile is the value where 25 % of the data fall below it Frequency 25 th percentile = 850 mgy cm Median = 950 mgy cm 75 th percentile = 1110 mgy cm 500 #COMPASM DLP (mgy cm)

16 Box Plot 10 th and 90 th percentile values can also be shown 10 th percentile = 760 mgy cm 90 th percentile = 1360 mgy cm Frequency #COMPASM DLP (mgy cm)

17 Box Plot DLP (mgy cm) = Frequency DLP (mgy cm) #COMPASM16 17

18 Abdo/Pelvis IH DRL using DLP Upper DRL = 800 mgy cm Lower DRL = 206 mgy cm DLP (mgy cm) HC DRL = 874 mgy cm #COMPASM16 18

19 Abdo/Pelvis IH DRL using CTDI HC DRL = 18 mgy Upper DRL = 15 mgy Lower DRL = 4.3 mgy CTDIvol (mgy) #COMPASM16 19

20 Abdo/Pelvis IH DRL using CTDI Fixed Tube Current CTDIvol (mgy) HC DRL = 26.5 mgy 5 0 #COMPASM16 20

21 Abdo/Pelvis IH DRL using CTDI Dose reduction available CTDIvol (mgy) HC DRL = 17.6 mgy #COMPASM16 21

22 Diagnostic Reference Levels The DRL process must be ongoing. Technology changes / Dose Creep New metrics are coming that better account for patient size (Size Specific Dose Estimates) #COMPASM16 AAPM report 204 SSDE 22

23 Bonn Call For Action Manufacturing Safety 3) Strengthen manufacturers role in contributing to the overall safety regime. R & D: Develop technical solutions to reduce radiation exposure Clinically: Get involved in RFPs with a Medical Physics and Radiation Safety Lens #COMPASM16 23

24 Bonn Call For Action Manufacturing Safety Be reasonable! Don t be over #COMPASM16 24

25 Bonn Call For Action Manufacturing Safety Be reasonable! Don t be under sold! #COMPASM16 25

26 Bonn Call For Action Education and Training 4) Strengthen radiation protection education and training of health professionals Prioritize radiation protection education and training Participate in radiation protection curricula of medical and dental schools Ensure training on new technologies #COMPASM16 26

27 Bonn Call For Action Education and Training OK to build off existing resources #COMPASM16 27 rpop.iaea.org/rpop/rpop/content/additionalresources/posters

28 Bonn Call For Action Strategic Research Agenda 5) Strategic research agenda for radiation protection in medicine. Strengthen investigations in low-dose health effects Improve methods for organ dose assessment Study mechanisms for individual differences in radiosensitivity and hypersensitivity to radiation Better understand deterministic effects, cardiovascular effects, etc #COMPASM16 28

29 Bonn Call For Action Strategic Research Agenda Question: At what tissue absorbed dose (skin dose) do we expect to see the onset of deterministic effects (transient erythema)? a) 200 mgy b) 2000 mgy c) mgy d) cgy #COMPASM16 29

30 Bonn Call For Action Strategic Research Agenda Question: At what tissue absorbed dose (skin dose) do we expect to see the onset of deterministic effects (transient erythema)? (most people answered correctly) a) 200 mgy b) 2000 mgy c) mgy d) cgy #COMPASM16 30

31 Bonn Call For Action Strategic Research Agenda Question: At what tissue absorbed dose (skin dose) do we expect to see the onset of deterministic effects (transient erythema) for Type 2 diabetes patients? (most people answered correctly) a) 200 mgy b) 2000 mgy c) mgy d) Not known, but less than 2000 mgy #COMPASM16 31

32 Bonn Call For Action Radiation Safety 8) Strengthen radiation safety culture in health care Closer co-operation between different specialties using radiation. Recognize role of medical physics as an independent profession in healthcare. #COMPASM16 32

33 Bonn Call For Action Risk vs Benefit 9) Foster an improved radiation benefit-risk-dialogue. Increase awareness about radiation benefits and risks. Improve risk communication skills of healthcare professionals and radiation protection professionals. #COMPASM16 33

34 Bonn Call For Action Risk vs Benefit Question: Which of the following statements best summarizes risk based on the linear non-threshold model? a) There is no safe dose given the linear nature of the model there is cancer risk at any radiation dose b) Below levels of about 100 msv above background from all sources combined, the observed radiation effects in people are not statistically different from zero #COMPASM16 34

35 Bonn Call For Action Risk vs Benefit Question: Which of the following statements best summarizes risk based on the linear non-threshold model? (most people answered a) ) a) There is no safe dose given the linear nature of the model there is cancer risk at any radiation dose b) Below levels of about 100 msv above background from all sources combined, the observed radiation effects in people are not statistically different from zero #COMPASM16 35

36 Health Physics Society Statement on LNT because of statistical uncertainties in biological response at or near background levels, the LNT hypothesis cannot provide reliable projections of future cancer incidence from low-level radiation exposures. below levels of about 100 msv above background from all sources combined, the observed radiation effects in people are not statistically different from zero. #COMPASM

37 AAPM Statement on LNT Discussion of risks related to radiation dose from medical imaging procedures should be accompanied by acknowledgement of the benefits of the procedures. Risks of medical imaging at effective doses below 50 msv for single procedures or 100 msv for multiple procedures over short time periods are too low to be detectable and may be nonexistent. Predictions of hypothetical cancer incidence and deaths in patient populations exposed to such low doses are highly speculative and should be discouraged #COMPASM

38 Canada Safe Imaging Canada s answer to the Bonn Call to Action The delivery of health care is a provincial responsibility but a focused national strategy and a unified effort is needed to ensure radiation safety in medical imaging for all Canadians #COMPASM16 38

39 Canada Safe Imaging Members - Canadian Association of Medical Radiation Technologists - Canadian Association of Nuclear Medicine - Canadian Association of Radiologists - Canadian College of Physicists in Medicine - COMP - Canada Health Infoway - MEDEC Canada s Medical Technology Companies #COMPASM

40 Canada Safe Imaging Mission Strengthening medical radiation protection in patients Promote procedural appropriateness for greatest medical benefit Facilitate scientific inquiry on the effects of radiation on human health #COMPASM