The Alliance for Radiation Safety in Pediatric Imaging

1. The Alliance for Radiation Safety in Pediatric Imaging Image Gently in Nuclear Medicine: What Every Referring Provider Should Know

2. Introduction • Role of the referring provider • Understanding radiation risks • Communicating risk to families • Conclusion

3. Introduction Introduction

4. Introduction • The Image Gently campaign is an initiative of the Alliance for Radiation Safety in Pediatric Imaging, which includes • the Society for Pediatric Radiology, • the American College of Radiology, • the American Society of Radiologic Technologists, • the American Association of Physicists in Medicine, • the Society of Nuclear Medicine and Molecular Imaging (SNMMI), and • the SNMMI Technologist Section

5. Introduction • The mission of the ‘Image Gently Alliance’ is to improve the safety and effectiveness of the imaging care of children worldwide • This is achieved through increased awareness, education and advocacy on the need for the appropriate examination and amount of radiation dose when imaging children • It launched on 1/22/08; since then 24,748 medical professionals have taken the image gently pledge

6. Introduction • What is nuclear medicine? • Imaging specialty that that uses very small amount of radiotracers or radiopharmaceuticals to create images of the human body • Nuclear medicine scans provide functional information and frequently complement other imaging tests including computed tomography (CT), ultrasound and magnetic resonance imaging (MRI) • Frequently identify abnormalities very early in the disease course

7. Introduction • What is molecular imaging? • Visualization, characterization, and measurement of biological processes at the molecular and cellular levels in humans • It personalizes patient care by characterizing specific disease processes in different individuals • The techniques used include nuclear medicine, magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), optical imaging, ultrasound and other modalities

8. Introduction • Radiopharmaceuticals can also be used for treatment of certain medical conditions • Example 1- Radioactive iodine to treat hyperthyroidism and cancers of the thyroid gland • Example 2: Radioactive iodine coupled with an agent called MIBG (I-131 MIBG) that is being used as an investigational drug for neuroblastoma

9. Your role Your role

10. Your role What is your role as a referring provider who orders these tests? • Be every child’s advocate • Be aware of opportunities to lower radiation dose in children by sending your patients to facilities that have been accredited by the American College of Radiology and other accrediting bodies • Encourage parents to ask questions and then direct them to this website

11. Your role • Make every effort to reduce the radiation dose to the children • Order only an indicated exam • Discussing the clinical situation with the nuclear medicine physician consultantto help decide if an alternative test might be better

12. Your role • Be radiation aware • Ensure that your imaging facility uses appropriate equipment, dosages and techniques for children, and those performing and interpreting these studies are qualified and experienced • Learn about risks of radiation and risk versus benefits of different imaging tests

13. Your role • What you should tell parents about nuclear medicine and radiation safety? • Use this presentation and the FAQs section and the parent brochure available on the Image Gently website to guide you • How do I know I am ordering the right test? • Use the indications of commonnuclear medicine procedures posted on the Image Gently website • When in doubt, ask your nuclear medicine colleagues

14. Radiation risks Radiation risks

15. Radiation risks • Nuclear medicine involves the administration of small amounts of radiopharmaceuticals that emit radiations such as γ-rays, x-rays, β-particles, or positrons • These low levels of ionizing radiation may have adverse health effects, of which carcinogenesisis of greatest concern • In the dose range of most nuclear medicine procedures, there is only limited human epidemiologic data and biologic investigations can be contradictory • The consensus is to assume that the risk at the lower doses with medical radiation can best be estimated by a linear extrapolation from higher doses for radiation protection purposes

16. Radiation risks • Much of the current understanding about the risk of exposure to ionizing radiation for humans is based on the Life Span Study of the survivors of the bombings of Hiroshima and Nagasaki as reported by the Radiation Effects Research Foundation • The Life Span Study demonstrates that the risk of ionizing radiation varies with both age and sex

17. Radiation risks • Younger subjects have a significantly higher risk than older subjects for most cancers • Actively growing tissues of younger subjects are more radiosensitive • Younger subjects have a longer life span that allows for a longer time for the risk to manifest • Girls demonstrated a higher risk for cancer induction than boyswhich is, in large part, attributable to the excess risk of breast cancer

18. Radiation risks • Radiation dose may be different in children as compared to adults due to patient size, organ size and orientation and organ distribution of administered radiopharmaceutical • When the administered activity is scaled by weight, the radiation dose to the patient is slightly less for smaller patients than for larger patients

19. Radiation risks • The radiation risk per unit dose however increases in younger patients. To some extent, these two effects compensate for each other • The risk depends on the dose delivered to each radiosensitive organ and the risk of cancer induction for that organ

20. Radiation risks • The organ receiving the highest dose is referred to as the critical organ • The effective dose is a commonly used dose metric that is used when discussing patient dose to a population of patients. It is the weighted sum of the individual organ doses based on the biologic radiosensitivity of each organ • These estimates are averages over a wide range of patients at each age. They do not take into consideration individual differences in anatomy and physiology from the standard models

21. Radiation risks

22. Radiation risks • It is quite challenging to optimize protocols for pediatric nuclear medicine • There are risks associated with the scan duration and injected activity • Longer scan durations are associated with increased possiblity of motion artifacts, patient discomfort, and sedation-related complications • Increased injected radioisotope activity is linked with an uncertain but small possible increased risk of cancer

23. Radiation risks • In the absence of truly “optimal” protocols, nuclear medicine physicians try to develop protocols that provide sufficient image quality with minimal risk to the patient • In general, the benefits of appropriate imaging studies generally far outweigh any patient risk

24. Communicating risk Communicating radiation risk

25. Communicating risk • Media reports and the general public are increasingly interested in risks from medical radiation • There is particular concern for young children because they are more sensitive to radiation than adults for most cancers • It is extremely important that you as a member of patient care team be able to effectively communicate with patients and families about the medical use of radiation, radiation dose and risks involved

26. Communicating risk • When patients or their parents ask about radiation dose, what they are really asking about is risk • It is no longer sufficient to indicate that these procedures are safe. The patients and their families need to be reassured, their concerns understood and there questions answered • Experience has shown that parents can be provided with dosimetric and risk information, including a possible risk of radiation-induced cancer. Such information typically does not adversely affect the willingness to undergo an appropriate medical imaging test

27. Communicating risk • The most effective way to communicate radiation risk to the public continues to be a topic of discussion • One approach is to discuss with the patients and their families that radiation exposure from a nuclear medicine test has some risks, just like risks from other medical tests, even prescription drugs • They can be told that radiation dose from these tests may slightly increase the risk of getting cancer. The risk is even higher in younger children, but is still very small

28. Communicating risk • It can be explained that the radiation dose to their child from a nuclear medicine procedure is in a similar range of many other radiologic tests. It is also comparable to the exposure that that individuals get from natural background radiation in 1 year

29. Communicating risk • One can also compare the cancer risk associated with radiation exposure to the natural risk of cancer • An alternative approach would be to compare the risk associated with radiation from medical imaging to other lifetime risks • These concepts are explained diagrammatically in the next two slides

30. For a 10-y-old receiving 99mTc-MDP bone scan, excess attributable risk for cancer death is 1 in 2,500 • In this figure, there are 2,500 small circles • Lone red star at lower right represents 1 case in 2,500 in which bone scan patient may contract fatal cancer • 550 dark blue circles that represent number of the original 2,500 that will naturally die of cancer (22%) Fahey FH, Treves ST, Adelstein SJ. Minimizing and Communicating Radiation Risk in Pediatric Nuclear Medicine J Nucl Med. 2011;52:1240-1251

31. Fahey FH, Treves ST, Adelstein SJ. Minimizing and Communicating Radiation Risk in Pediatric Nuclear Medicine J Nucl Med. 2011;52:1240-1251

32. Conclusions • Order only an indicated exam • Be radiation aware • Always weigh the risks versus benefits • Be equipped to discuss radiation risks of nuclear medicine tests with patients and their families as needed • Take the image gently pledge. Use the image gently website as a resource

33. ACR pediatric imaging appropriateness criteria http://www.acr.org/Quality-Safety/Appropriateness-Criteria/Diagnostic/Pediatric-Imaging • ACR and combined ACR, SPR and SNM guidelines for nuclear medicine procedures http://www.acr.org/Quality-Safety/Standards-Guidelines/Practice-Guidelines-by-Modality/Nuclear-Medicine • Fahey FH, Treves ST, AdelsteinSJ. J Nucl Med. 2011;52:1240-1251 • www.snmmi.org/dose