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  1. 1. Radiation protection review for credentialed fluoroscopy operators @ BWH Dept. of Health Physics and Radiopharmacology Brigham and Women’s Hospital
  2. 2. Radiation protection review for credentialed fluoroscopy operators @ BWH Purpose:  Review safe practices of fluoroscopy, including radiation protection strategies for patients and staff  Review occupational dosimetry program  Comply with Massachusetts regulations  Stimulate dialogue amongst fluoroscopy users and radiation oversight committees
  3. 3. Radiation protection review for credentialed fluoroscopy operators @ BWH Who is responsible for fluoroscopy oversight?  Government US FDA guidance/advisories for manufacturers, users, and public Massachusetts Dept. of Public Health inspects and enforces regulations in Massachusetts  Accreditation organizations: JCAHO, ACR  BWH Radiation Safety Committee  Medical Directors of Radiology, Cardiology, etc.
  4. 4. Radiation protection regulations 105CMR120- Mass. Regulations for the Control of Radiation 120.400: X‑RAYS IN THE HEALING ARTS 120.405: Fluoroscopy Describes:  Shielding requirements  Tube output, beam filtration and limitation  Exposure and dose rate limits  Recording of fluoroscopy time and dose  Protection from scattered x-rays  Operator qualifications………
  5. 5. Radiation protection regulations 120.405: X‑RAYS IN THE HEALING ARTS  Operator Qualifications.  (1)   A facility shall ensure that only a licensed physician or a radiologic technologist who is trained in the safe use of fluoroscopic x-ray systems licensed in accordance with 105 CMR 125.000 shall be allowed to operate these systems. All persons using fluoroscopic x-ray systems shall have, at a minimum, documented training in the topics specified 105 CMR 120.405(K)(2).
  6. 6. Radiation protection regulations 120.405: X‑RAYS IN THE HEALING ARTS Describes:  Operator training: (2)   Training to meet requirements of 105 CMR 120.405(K)(1) shall include, but not be limited to the following:  (a)   Principles and operation of the fluoroscopic x-ray system;  (b)   Biological effects of x-ray;  (c)   Principles of radiation protection;  (d)   Fluoroscopic outputs;  (e)   High level control options;  (f)   Dose reduction techniques for fluoroscopic x-ray systems; and  (g)   Application requirements of 105 CMR 120.000.
  7. 7. Radiation protection regulations 120.405: X‑RAYS IN THE HEALING ARTS Describes:  Operator training: (3)   The facility shall maintain all records relating to compliance with the training requirements for five years. (4)   The facility shall establish policies and procedures for restricting the use of fluoroscopic systems to only those physicians who have been granted privileges for the use of fluoroscopy based on a determination of adequate training and knowledge of the curriculum of 105 CMR 120.405(K)(2). (5)   The facility shall ensure that all non-radiologist physician using fluoroscopy equipment obtain annual training in Radiation Safety/Radiation Protection and maintain all records relating to compliance with this training requirement for five years.
  8. 8. Fluoroscopy safety training @ BWH Since 1990:  All new fellows, residents, and attending physicians undergo a training course with take-home reading materials, exam, and fluoroscopy competency assessment.  Upon successful completion, are issued a certificate and entered into BICS as holding Fluoroscopy privileges  Ad hoc retraining/radiation safety in-services presented
  9. 9. Fluoroscopy safety training @ BWH As of 2008 (non-radiologist physicians):  BICS Fluoroscopy privileges will expire annually  Recertification takes place by viewing study materials and retuning quiz to Health Physics  Ad hoc retraining/radiation safety in-services presented
  10. 10. Somatic and genetic damage depends on exposure parameters  the quantity of ionizing radiation to which the subject is exposed  the rate of exposure  the ionization ability of the radiation  the volume of tissue exposed  the types of tissues exposed
  11. 11. Activity  Disintegration/sec=1 Becquerel (Bq)  37 billion Bq = 1 curie Dose (Absorbed)  1 joule/kg=1 Gray(Gy)  1Gray=100 rad =100,000 mrad Dose (Equivalent)  Gray x quality factors= Sievert (Sv)  1 Sievert =100 rem =100,000 mrem Radiation Units U.S. Dept. of Energy
  12. 12. Biologic Effects of Ionizing Radiation (IOM) BEIR VII, 2005
  13. 13. Radiation risks Stochastic effects (= non-threshold, increasing probability with dose) genetic mutation genomic instability cancer induction
  14. 14. Genomic Instability Sometimes DNA damage produces later changes which may contribute to cancer. Gene Expression A gene may respond to the radiation by changing its signal to produce protein. This may be protective or damaging. Effects of DNA Damage DNA is the most important molecule that can be changed by radiation Studies have shown that most radiation-induced DNA damage is normally repaired by the body Gene Mutation Sometimes a specific gene is changed so that it is unable to make its corresponding protein properly Chromosome Aberrations Sometimes the damage effects the entire chromosome, causing it to break or recombine in an abnormal way. Sometimes parts of two different chromosomes may be combined Cell Killing Damaged DNA may trigger apoptosis, or programmed cell death. If only a few cells are affected, this prevents reproduction of damaged DNA and protects the tissue. U.S. Dept. of Energy
  15. 15. Review for credentialed fluoroscopy operators @ BWH Risks of radiation exposure: In 2004, ionizing radiation classified as a known carcinogen by the US. National Toxicology Program. The category "known to be a human carcinogen" is reserved for those substances for which there is sufficient evidence of carcinogenicity from studies in humans that indicates a causal relationship between exposure to the agent, substance, or mixture and human cancer." Radiogenic cancer = stochastic risk
  16. 16. E. Picano, BMJ 2004
  17. 17. Radiation risks (non-stochastic) Commonly referred to as deterministic effects:  threshold-related symptoms  worsen with dose includes:  Skin changes (erythema /hair loss/ulceration)  Cataracts  Teratogenesis
  18. 18. Doses in interventional procedures Not knownNot knownNot knownSkin cancer >25 to eye>250 to eye>5Cataract 5050010Telangiectasia 9090018Dermal necrosis 7070014Dry desquamation 353507Permanent epilation 101002Transient erythema Minutes fluoro at 0.2 Gy/min Minutes fluoro at 0.02 Gy/min Threshold dose (Gy) Effect from ICRP 85, Interventional procedures-avoiding radiation injuries
  19. 19. Radiation – dose limits, patients? Even with increased utilization of imaging procedures and image-guided interventions, there is no maximum permissible dose or procedure volume for medically indicated procedures.  Weigh risk vs. benefit  Advise patient if deterministic effect possible  If patient is pregnant, consider limited exam, or alternative (MRI, sonography)  Utilize dose-saving protocols
  20. 20. Fluoroscopy dose-saving protocols Whenever and wherever possible:  Limit beam-time on (use last image hold)  Reduce tube current (mA)  Use lower pulse sequence fluoroscopy  Limit magnification  Maintain adequate x-ray source-skin distance  Keep Image intensifier as close as possible to patient  Apply positive beam limitation (collimators)  Record* and minimize fluoroscopy time
  21. 21. Fluoroscopy dose reporting 105 CMR 120 (as of 6 OCT 2006) Each facility performing fluoroscopically-guided interventional procedures shall conduct patient dose evaluation for any procedure that has a reasonable probability of resulting in a deterministic injury as further defined in 105CMR120.405(L)(5). * * Any cumulative absorbed dose to the skin equal to or greater than 1 Gy (100 rads)
  22. 22. Review for credentialed fluoroscopy operators @ BWH * Record and minimize fluoroscopy time Fluoroscopy procedures in which the dose exceeds 1,000 mGy are reported to Medical Physics for dose calculations which are then sent to the:  Radiation Safety Officer  Radiation Safety Committee  In some instances, the patient’s primary care physician will be notified for deterministic effect surveillance and patient follow-up.
  23. 23. Sample dose calculation, Medical Physics
  24. 24. Law of Bergonié and Tribondeau = rapidly dividing, less differentiated cells more sensitive to radiation effects …..therefore the conceptus is at higher risk. Pregnant females should not be irradiated unless absolute medical necessity Pregnant radiation workers restricted to much lower doses. Why limit exposure to pregnant patients (and staff)?
  25. 25. Probability of bearing healthy children as a function of radiation dose from ICRP 84, Pregnancy and radiation Dose to conceptus (mGy) above natural background Probability of no malformation Probability of no cancer (0-19 years) 0 97 99.7 1 97 99.7 5 97 99.7 10 97 99.6 50 97 99.4 100 97 99.1 >100 Possible, see text Higher
  26. 26. Conceptus dose, interventional procedures (mGy) For BWH-specific protocols, please see: http://brighamrad.harvard.edu/education/fetaldose/
  27. 27. Part III-Occupational exposures and radiation protection program
  28. 28. Copyright ©Radiological Society of North America, 1999 Brateman, L. Radiographics 1999;19:1037-1055 Schematic provides a graphical representation of definitions of radiation safety terms as they are used in radiation protection (with an x-ray tube as the radiation source)
  29. 29. Scattered radiation fields  Various studies have shown scattered radiation in a fluoroscopy procedure  room will range from 0.03 to 0.5 R per hour of actual x-ray beam time. D. Allard, CHP; Health Physics Society
  30. 30. Radiation – dose limits for staff Maximum permissible dose, annual limits: Occupational workers: Whole body = 5,000 mrem/yr (= 50 mSv) Eyes = 15,000 mrem/yr (= 150 mSv) Skin = 50,000 mrem/yr (= 500 mSv)
  31. 31. Radiation – occup.dose limits If declared pregnancy = 500 mrem/gestational period (5.0 mSv) = not to exceed 50 mrem/month (0.5 mSv)
  32. 32. Radiation safety strategies Decrease time around source Increase distance from source Use appropriate shielding Contamination control (PPE) Monitor badge reports - ALARA
  33. 33. Intensity of the radiation dramatically drops off with distance, due to the inverse square law: I1/I2 = D2 2 /D1 2 Sample: exposure rate @ 0.5 m = 50 mR/hr What is the exposure rate @ 1.5 m (50mr/hr)/( ? mr/hr) = (1.5 m)2 /(0.5 m)2 50/x = 2.25/0.25 50/x = 9.0 50 = 9x x = 50/9 = 5.56 mR/hr @ 1.5 m
  34. 34. Staff and trainees working with ionizing radiation are issued monthly radiation dosimeters. You may be issued: - a single collar badge, with red icon (WORN ABOVE Pb APRON) - a single whole body badge, with black icon (WORN BELOW Pb APRON) - both badges, if you regularly operate the fluoroscope during interventional studies. - a ring badge, if you handle > 1.0 mCi of radionuclides - a fetal dose monitor, if pregnancy declared - an Area monitor badge will be placed in your workspace if little to no exposure is anticipated
  35. 35. Dosimeter exposure estimates calculated several ways EDE 1 – 2 dosimeters; one worn at waist (under Pb apron), the other at collar level (outside of Pb apron) Assigned deep dose =[1.5 (waist) + 0.04 (collar)] most commonly done with routine fluoroscopy
  36. 36. Dosimeter exposure estimates EDE 2 – one whole body dosimeter worn at collar level (outside of Pb apron) Assigned deep dose = 0.3 x (whole body badge) most commonly used for occasional fluoroscopy users
  37. 37. BWH Deep dose equivalent (~ 99% < 500 mrem) 2009 BWH Deep dose equivalent N = 1530 (98.5% < ALARA I) 807 605 28 35 15 17 16 7 0 100 200 300 400 500 600 700 800 900 <1.0 mrem 1-49 50-99 100-199 200 -299 300 -499 500 -999 1000 -1999 2000+ DDE (mrem) #ofstaff ALARA I (10% MPD)
  38. 38. As Low as Reasonably Achievable (ALARA) – staff notified if dose exceeds 10% of MPD
  39. 39. Sample ALARA notification/response
  40. 40. BWH Radiation Safety Contacts Health Physics & Radiopharmacology Main # = 617 732 6056 24 hr emergency pager = 33330 Christopher Martel, MS, DABHP Director & Radiation Safety Officer = 617 732 6057 A. Robert Schleipman, RT, CNMT, MSc IRB, Occupational Dosimetry, Training = 617 732 5963 Medical Physics, Radiology Richard Nawfel, MS Dose calculations, equipment testing, training = 617 732 7201
  41. 41. Radiation Safety Liaisons have been established for each area to assist you with badges, PPE, etc. CDIC = Kelley Grassi, RT EP Lab = Jim McConville, RT, CNMT Endoscopy = Sandra Cialfi, RN Pain Management = Diane Palombi, RN Interventional Radiology = Carol Upson, RT Diagnostic (L1) Radiology = Charles David Healy, RT Emergency Dept. = Angela McLaughlin, RT Nuclear Medicine = Victor Gerbaudo, PhD O.R. Nursing = Mike Bickerstaff, RN O.R. Radiology equipment = Steve Kenary, RT
  42. 42. Radiation protection review for credentialed fluoroscopy operators @ BWH Process:  BICS fluoroscopy credential expires annually*  Participant reviews slide show  Participant contacts RSO with any questions  Participant completes and returns quiz  BICS Fluoroscopy credentials renewed for 12 months *Radiologists, by nature of their continuing education requirements, are exempt from annual radiation safety/fluoroscopy retraining
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