1. RADIATION PROTECTION Dr.P.P.Mohanan Thrissur

2. 2 Outline Basis for protection, radiation risk and recommendations Personal dosimetry Protection tools

3. Vulnerable Interventional Cardiologist

4. POTENNTIAL HAZARDS

5. 5 Coronary interventionalists must also have a thorough knowledge of specialized equipment, techniques, and devices used to perform PCI competently

6. AHA Scientific Statement - 2014 Approaches to Enhancing Radiation Safety in Cardiovascular Imaging A Scientific Statement From the American Heart Association Recommendations All healthcare providers who can request cardiac imaging procedures should be required to know (a) which cardiac imaging tests use ionizing radiation; (b) basic concepts related to medical radiation exposure, including the concepts of absorbed dose and effective dose; and (c) typical dose estimates for the most commonly used cardiac imaging procedures (Class I; Level of Evidence C). All healthcare providers who will perform cardiac imaging with ionizing radiation, including interventional cardiologists and electrophysiologists, should be required to demonstrate adequate knowledge of contemporary dose-optimization techniques for patients and dose-minimization techniques for operators and staff (Class I; Level of Evidence C).

7. Recommendations 1. Education. of clinicians and patients 2. Justification that a particular cardiac imaging test with radiation is needed 3. Optimization of radiation exposure (choosing the smallest dose that provides high-quality images).

8. Lecture 6: Standards and guidance 8 Importance of training European Guidelines published in 2000. Radiologists 30-50 hours Cardiologists 20-30 hours Other doctors using fluoroscopy X rays systems 15- 20 hours Available at: http://europa.eu.int/comm/environ ment/radprot

9. Lecture 6: Standards and guidance 9 Cardiologist Patient Protection Responsibilities Advice of qualified expert Training criteria Optimization Equipment design and suppliers Quality assurance Justification

10. Lecture 6: Standards and guidance 10 Limits on Patient Doses? There are no regulatory limits on the radiation dose a patient may receive – Question: do you think that the benefit outweighs the risk???

11. Time of onset of clinical signs of skin injury depending on dose received dose received Symptoms Dose range Time of onset (Gy) (day) (Gy) (day) l Erythema 3-10 14-21 l Epilation >3 14-18 l Dry desquamation 8-12 25-30 l Moist desquamation 15-20 20-28 l Blister formation 15-25 15-25 l Ulceration >20 14-21 l Necrosis >25 >21 Ref.: IAEA-WHO: Diagnosis and Treatment of Radiation Injuries.

12. 12 X-Ray Scatter radiation Measures taken to reduce radiation exposure to patient will also benefit the operator/cath. lab. staff

13. Radiation risk Stochastic effect Deterministic effect

15. Deterministic vs. stochastic effects (representative, not scaled ). Picano E et al. Eur Heart J 2014;eurheartj.eht394

16. Radiation effects Early (deterministic only) Local Radiation injury of individual organs: functional and/or morphological changes within hrs-days-weeks Common Acute radiation disease Acute radiation syndrome Late Deterministic Radiation dermatitis Radiation cataracta Teratogenic effects Stochastic Tumours Leukaemia Genetic effects

17. Deterministic effect Gray is unit of exposure of radiation ONE CHEST X RAY 0.15 mGRAY 10000 chest x ray Or 100 CT abdomen = 30 mins to 1 hr fluoroscopy exposure

18. 18 1- 5 mSv/h 0.5 – 2.5 mSv/h 2- 10 mSv/h

19. 19 Limits on Occupational Doses (ICRP)* Annual Dose Limit (mSv) Effective dose, worker20 Equivalent dose to lens of eye 150 Equivalent dose to skin500 Equivalent dose to hands and feet 500 Effective dose to embryo or fetus 1 Effective dose, public1 *Please follow the recommendations as prescribed by your national authority

20. Threshold doses for some deterministic effects 0,1 Gy – detectible opacities 0,2 Gy – sterility for woman 0,4 Gy – visual impairment 0,4 Gy – temporary sterility for man 0,4 Gy – depression of haematopoiesis 1,0 Gy – chronic radiation syndrome 2,0 Gy – permanent sterility for man

21. Radiation dose in coronary angiography and Intervention : Journal of Medical Radiation Sciences

22. A Typical Fluoroscopic Lab Overhead shields need to be positioned down next to the patient and adjacent to the image intensifier to seal scatter off from below. Table skirts shield the highest backscatter levels from the x-ray tube.

23. 23 To obtain the images … Two technologies are used: – Image intensifier – Flat panel detector

24. The X-ray Imaging Process Absorption and transmission of x-rays contribute to the imaging process and patient dose. Scattered or partially absorbed x–rays contribute to occupational exposure, but are less than 1% of the primary beam intensity.

26. 26 Characteristics of procedures & lesions Comparison of Philips H 3000 and Innova 2000 in PCI Characteristics of procedures & lesions %

27. Recommendations 1. Education. of clinicians and patients 2. Justification that a particular cardiac imaging test with radiation is needed 3. Optimization of radiation exposure (choosing the smallest dose that provides high-quality images).

28. Basic Radiation Safety Techniques Time - As exposure time increases, dose accumulates -- Keep fluoro times as short as possible. A bell or buzzer will go off after 5 minutes of beam time, keep track of fluoro time, Distance - As distance from the radiation source increases, the radiation intensity decreases rapidly -- Keep patient anatomy and staff as far away from the x-ray tube port as possible Shielding - Diagnostic x-rays are easily shielded with thin sheets -- Wear lead aprons, thyroid shields, leaded glasses and use overhead leaded shields and table skirts

29. 29 Optimization means... To avoid acquiring more images than necessary: – Take care of the fluoroscopy time. – Take care of the number of series. – Take care of the number of frames per series. To avoid acquiring images with more quality (and more dose) than necessary: – It could be possible to accept sometimes some noisy images in fluoroscopy and also in cine acquisitions.

30. ALARA rule As low as reasonably achievable Reduce number of exam Reduce time of exam Use alternaive

31. 31 Minimize Exposure Time Everything you do to minimize exposure time reduces radiation dose!! – Minimize fluoro and cine times – Whenever possible, step out of room – Step behind barrier (or another person) during fluoro or cine – Use pulsed fluoroscopy– minimizes time X ray tube is producing X rays

32. 32 Siemens Axiom Artis Cine normal mode 20 cm PMMA 177  Gy/fr (entrance PMMA) Siemens Axiom Artis, Fluoro low dose 20 cm PMMA 13  Gy/fr (entrance PMMA)

33. Lecture 9: Optimization of Radiation Protection in Cardiology 33 The proposed reference levels for Coronary Angiography and PTCA were DAP 45 Gycm 2 and 75 Gy cm 2 ; fluoroscopy time 7.5 min and 17 min and number of frames 1250 and 1300, respectively.

34. 34 Influence of operation modes: from low fluoroscopy to cine, scatter dose rate could increase in a factor of 10 (from 2 to 20 mSv/h for normal size)

35. 35 Distance between patient and detector

36. 36 d 2d Because the same energy is spread over a surface 4 times larger at a doubled distance, the same object will receive only a fourth of the dose when moved away from “d” to “2d” Source Doubling the distance from the source divides the dose by a factor of 4 The inverse square law

37. 37 The inverse square law

38. 38 Collimation

39. 39 Collimators use in reduce exposure FOV 15 dose reduction 25%

40. 40 FOV 20 Collimators reduce exposure

41. 41 Anti-scatter grid Increase DAP and skin dose x 2 times Improve image quality

42. 42 proper filtering improper filtering causes image deterioration FILTERING Filtering prevents image saturation in low absorption areas

43. 43 Optimization requires………. Knowledge of factors contributing to patient and staff radiation dose patient factors procedural factors equipment (machine) factors Knowledge of dose reduction capabilities of our X ray system Periodic update of our clinical and technical working protocols

44. 44 Optimization is especially important in more complex PTCA procedures chronic total occlusion bifurcation lesion degenerated saphenous vein graft lesion lesion in severely tortuous vessel ostial lesion

45. 45 Exposure variation in exposure rate (DAP rate) with projection Cusma JACC 1999 ProjectionFluoroscopy entrance dose rate (mGy/min) Cine entrance dose rate (mGy/min) AP31388 RAO 30°19203 LAO 40°20216 LAO 40°, Cran 30° 80991 LAO 40°, Cran 40° 991236 LAO 40°, Caud 20° 29341

51. 51 Optimisation 1.Use of the wedge filter on bright peripheral areas 2.2-3 sequences (except for difficult anatomic details) 3.12.5-15 frames/s (25-30 only if heart rate exceeds 90-100 bpm or in paediatric patients) 4.60 images per sequence at average (12.5-15 fr/s) except if collaterals have to be imaged or in case of slow flow

52. 52 Basic Radiation Protection Time (T), Distance (D), and Shielding (S) Time– minimize exposure time Distance– increasing distance Shielding– use shielding effectively; portable and pull-down shields, protective aprons; stand behind someone else

53. 53 1- 5 mSv/h 0.5 – 2.5 mSv/h 2- 10 mSv/h

54. Lecture 7: Occupational exposure and protective devices 54 Radiation Monitoring Badge Plastic filter Metal filtersOpen windows Open window

55. Lecture 7: Occupational exposure and protective devices 55 The use of electronic dosimeters to measure occupational dose per procedure helps in the optimization

56. Lecture 7: Occupational exposure and protective devices 56 Types of Personal Radiation Monitors Film Thermoluminescent dosimeters (TLDs) Optically stimulated luminescence (OSL) dosimeters Electronic personal dosimeters

57. 57 Advantages and Disadvantages of Personal Radiation Monitors Electronic dosimeters— insensitive to heat, no permanent record, minimum dose > 0.1 mSv, no imaging capability, calibration can be difficult, must rely on employee for care of device (somewhat delicate), employee must read-out dosimeter and record results, weekly or monthly readout

58. Multiple Badge Fluoroscopic Dosimetry Effective dose equivalent is calculated for multiple badge wearers using the ANSI formula as required by CT State DEP regulatory guidance. Effective Dose Equivalent = (0.11 x collar badge) + (0.89 x waist badge) An American National Standard (ANSI) Criteria for Performing Multiple Dosimetry

59. Protection tools

60. 60 Personal protective equipment Registrants and licensees shall ensure that workers are provided with suitable and adequate personal protective equipment. Protective equipment includes lead aprons, thyroid protectors, protective eye- wear and gloves. The need for these protective devices should be established by the RPO.

61. 61 Weight: 80 grams Lead equivalent: 0.75mm front and side shields leaded glass Lead apron typically attenuates >90% Vest-Skirt Combination distributing 70% of the total weight onto the hips leaving only 30% of the total weight on the shoulders. Option with light material reducing the weight by over 23% while still providing 0.5 mm Pb protection at 120 kVp

62. C. Radiation Protection and How does it Work?

64. 64 0.25 mm lead 60 kV; 100% 2 - 3 % 100 kV; 100% 8 - 15 % Attenuation measured with lead aprons X ray beam filtration has a great influence!!

65. Thyroid collar Standard 0.5mm lead apron Protect you from 95% FROM RADIATION EXPOSURE

66. Wear Protective Eyewear “In the 59 interventional radiologists aged between 29 and 63 (median age 35), PSC cataracts were found in five participants and an additional 22 had evidence of PSC changes” 46% experienced changes in the eyes G. Eyewear

67. 67 DETERMINISTIC LENS THRESHOLD AS QUOTED BY ICRP OPACITIES THRESHOLD >0.1 Sv/year CONTINUOUS ANNUAL RATE >0.15 Sv/year CONTINUOUS ANNUAL RATE CATARACT

68. 68 UP TO 2 mSv IN LENS COULD BE RECEIVED IN A SINGLE PROCEDURE if protection tools are not used WITH 3 PROCED./DAY IT IS POSSIBLE TO RECEIVE 1500 mSv/year IN FOUR YEARS WILL BE POSSIBLE TO HAVE LENS OPACITIES

70. Lecture 7: Occupational exposure and protective devices 70 Radiation Protection of Hands Best way to minimize dose to fingers and hand: Keep your fingers out of the beam!!! Dose rate outside of the beam and on side of patient opposite X ray tube: Very low compared to in the beam!!!

71. 71 Protective Surgical Gloves Minimal effectiveness Transmission on the order of 40% to 50%, or more Costly ($40 US), not reusable Reduces tactile sensitivity Dose limit for extremities is 500 mSv Hands on side of patient opposite of X ray tube so dose rate is already low compared to entrance side Lead-containing disposable products are environmental pollutants

72. H. Gloves ProteX ProGuar d 2 Thicknesses Non-reactive Latex Anatomically correct Resterilize up to 4x Come sterile Sizes 6-9 w/ ½ sizes Reduces Radiation Powder Free FDA 510(k) Cost effective Beaded Cuff Thicker Feel Premium, Higher $ Soft-Touch™ interior finish Thinner Texture ATTENUATION 60 KvP80 KvP100 KvP120 KvP ProGuard RR1, ProteX PX-1 0.0088” / 0.22mm 45%35%26%23% ProGuard RR2, ProteX PX-2 0.012” / 0.30mm 55%43%35%31% Protech Radiation Reducing Gloves

78. Rate of appropriateness for the four procedures.

79. 79 Procedure optimization in the cath. lab. patients and staff share a lot…… – correct indications – fluoro time reduction – frame rate reduction (25 12,5/sec) – collimation/filtering – LAO cranial projection limitation – distance from X ray source – lead apron and thyroid protection – protective glasses and suspended screen (staff) (patient)