Presentation on theme: "Staff and Patient Radiation Protection In The Cath Lab"— Presentation transcript:
1 Staff and Patient Radiation Protection In The Cath Lab Andrés SinisterraAssistant Radiation Safety Officer for Medicine
2 Radiation vs. Radioactivity Energy in transit in the form of high speed particles and electromagnetic waves.Ionizing RadiationRadiation with enough energy so that during an interaction with an atom, it can remove tightly bound electrons from their orbits, causing the atom to become charged or ionized.RadioactivitySpontaneous transformation of an unstable atom and often results in the emission of radiation. This process is referred to as a transformation, a decay or a disintegration of an atom.
3 External vs. Internal Radiation Exposure External Exposure – X-rays, Diagnostic Procedures.Internal Deposition – Contamination from nuclear medicine patient undergoing a diagnostic or therapeutic procedure resulting in an ingestion of radioactive materials by the staff.+=T E D E
4 Units of Radiation Exposure RoentgenMeasure of electrical charge produced in air1,000 mr = 1RSSD ~3-10 R/minMeasure of energy absorbed, usually in tissue or bone.200 rad = transient erythema1 Gray = 100 RadRad (Gray)
5 Units of Radiation Exposure Rem (Sievert)Measure of occupational risk (cancer) from radiation exposure1,000 mrem = 1 Rem1 Sievert = 100 Rem1 R = 1 Rad = 1 Rem
15 INCIDENT X-RAYPHOTOELECTRONPhotoelectric effect occurs when an incident x-ray is totally absorbed during the ionization of the inner-shell electron. The incident photon disappears and the k-shell electron, now called a photoelectron, is ejected from the atom.
23 Be aware of critically exposed areas Headand shoulderskneesand toes !!!!!
24 30-cm FOVImage intensifier70-cmSSDMedium conventional fluoroscopySetting C for fluorographyFloor kVp is 110 Dose = 50 rad55-cmSSDMedium conventional fluoroscopySetting C for fluorographyFloor kVp is 80 Dose = 140 rad15-cm air gapPail of water 28-cm deep23-cm FOVImage intensifierThe effects of an air gap are significant, even if the image is properly collimatedPail of water 28-cm deep
25 Know Where Your Head Is At……!!! The greater the distance the greater the scatter
26 Mag Mode (Field-Of-View) The following Table illustrates the effect of changing Field-Of-View, or magnification modes, for a typical fluoroscopy systemMag Mode (Field-Of-View)ESE (R/min)Increase FactorNormal (9 inch)1.21.0Mag 1 (6 inch)2.92.4Mag 2 (4.5 inch)5.24.3
27 Inverse Square Law (X-Rays & Gamma Rays) For a point source, the intensity varies inversely as the square of the distance from the source.Scattered X-raysX-Ray Tube1 cm10,0002 cm2,5005 cm40010 cm10020 cm25Leakage Radiation
28 Basic Radiation Safety Principles TimeDistanceShieldingContamination Control
29 Radiation Exposure and Monitoring Whole Body Radiation BadgeWorn Underneath Pb ApronCollar Radiation BadgeWorn Outside Pb Apron At Neck LevelBLACK ICONRED ICONExtremity Radiation BadgeWorn on Primary HandClosest to Radiation Source
30 Whole Body Radiation Badge Collar Radiation Badge WornUnderneathPb ApronCollar Radiation BadgeWornOutsidePb Apron At Neck Level
31 So what’s the big deal where I put my @% badges ? D’OH !At Thyroid~45 cmAt Breast~30 cm
32 Get The Lead Out but Watch Your Back !! PROTECTIVE EQUIPMENTGet The Lead Out but Watch Your Back !!
33 As Low As Reasonably Achievable ALARA Level I> 10% of the maximum quarterly exposure limit (125 mrem)ALARA Level II> 30% of the maximum quarterly exposure limit (375 mrem)
36 Reducing Patient Dose During Fluoroscopy (And Yours) Get off the pedal!! – Fluoro intermittentlyCollimate and only expose clinical areaUse larger fields when possible(Magnification increases patient dose)Use distance of at least 30 cm for mobile units and 38 cm for fixed installationsUse appropriate mA and KVp
37 Reducing Patient Dose During Fluoroscopy (And Yours) Remember the egg timer!!!Be aware of the 5 minute timer (especially in high level mode)Have sufficient beam filtration> 90 KVp requires 2.5 mm Al to 3.5 mm 130 KVpFluoro only when necessarySchedule annual QA of equipment
38 Radiation DoseThe amount of energy deposited in any substance by ionizing radiation per unit mass of the substance. It is expressed numerically in rads (traditional units) or grays (SI units).Absorbed DoseDose EquivalentDeep Dose EquivalentEye Dose EquivalentShallow Dose EquivalentEffective Dose EquivalentCommitted Dose EquivalentTotal Effective Dose Equivalent
39 Radiation DoseAbsorbed Dose - The amount of energy deposited in any substance by ionizing radiation per unit mass of the substance. It is expressed numerically in rads (traditional units) or grays (SI units).Dose Equivalent - The dose equivalent (H) is the product of the absorbed dose in tissue, the quality factor and all other modifying factors at the location of interest. The unit is the rem (R) or the sievert (Sv).
40 Radiation DoseDeep Dose Equivalent (Hd) - Applies to external whole body exposure, means the dose equivalent at a tissue depth of 1 cm or greater.Eye Dose Equivalent - The external dose equivalent to the lens of the eye at a tissue depth of 0.3 cm.Shallow Dose Equivalent (Hg) - Applies to the external exposure of the skin or extremity. The dose equivalent at a tissue depth of cm averaged over an area of 1 cm2.
41 Radiation DoseCommitted Dose Equivalent (HE.50) - The dose equivalent (H) is a given organ or tissue that will be accumulated over 50 years following a single intake of radioactive material.Effective Dose Equivalent (HE) - The sum of the products of the dose equivalent (HT) to each organ or tissue and the weighting factor (WT) applicable to each of the body organs or tissues that are irradiated (HE = ‡” WTHT).Total Effective Dose Equivalent - The sum of the deep dose equivalent for external exposures and the committed effective dose equivalent for internal exposures.
42 Radiation Exposure Limits (State of Connecticut Administrative Regulations Sect )Type of ExposureRem Per Calendar QuarterWhole body; head and trunk; active blood-forming organs; lens of eyes, or gonads.Hands and forearms; feet and ankles.Skin of whole body.1.2518.757.5(1,250 mrem)(5.0 rem/yr)(18,750 mrem)(75 rem/yr)(7,500 mrem)(30 rem/yr)Fetus500 mrem Total Gestation(0.5 rem)
43 Radiation Exposure Limits (USNRC 10CFR20 - § )Type of ExposureRem Per Calendar YearThe total effective dose equivalent.5.0(0.05 Sv)The sum of the deep-dose equivalentand the committed dose equivalent toany individual organ or tissue otherthan the lens of the eye50(0.5 Sv)
44 Radiation Exposure Limits (USNRC 10CFR20 - § )Type of ExposureRem Per Calendar YearAn eye dose equivalentand A shallow dose equivalent to the skin or to any extremity.15 rem ( 0.15 Sv )50 rem ( 0.50 Sv )In Utero exposure to the Fetus0.5 rem Total Gestation(500 mrem & <50/mo)
45 Conditions For Exceeding Quarterly Doses To Whole Body Total Dose For Any Quarter< 3.0 remTotal Whole Body Dose<= 5 (N-18) remAll Previous Whole Body DosesPlusN = Your Age In YearsPrior Dose Must Be On a Clear Record! ! ! ! ALARA PROGRAM EXISTS ! ! ! !
46 Confidential Declaration of Pregnancy NRC requires a signed declaration of pregnancy for occupational workers to limit exposures to 500 mrem/9months or 50 mrem in any one month.
48 Radiation Exposures From ? Smoking a pack and a half of cigarettes a day will add about 1,300 mrem/year to one's effective doseFlying from New York to London results in the absorption of an extra2-3 mrem of cosmic radiation6-8 mrem from NY to Japan
49 Risks which Increase Chance of Death by 1 in 1 million a a B.L. Cohen and I.S. Lee, “Catalog of Risks Extended and Updated”, Health Physics, Vol. 61, Sept
50 Estimated Loss of Life Expectancy from Health Risks Health Risk Average Days of Life Expectancy LostSmoking 20 cigarettes/day (6.5 years)Overweight (by 20%) (2.7 years)All accidents combined (1.2 years)Auto accidentsAlcohol consumptionHome accidentsDrowningNatural background radiation 8Medical diagnostic x-rays 6All catastrophes (fire, flood, etc.) 3.51,000 mrem (1 rem) occupational radiation dose 11,000 mrem (1 rem)/yr for 30 years 30Note: Average U.S. occupational radiation dose is estimated at rem/year.
51 PROGRAM FOR IMPLEMENTING PATIENT INFORMED CONSENT ANDFOLLOW UP REGARDING HIGH DOSE SPECIALX-RAY PROCEDURES
52 Purpose:There are certain x-ray guided procedures that could result in the delivery of a radiation dose to an area of a patient’s skin of sufficient magnitude to produce clinical symptoms.This program was developed to inform patients of this potential risk prior to such procedures, determine if a procedure may lead to a large skin dose and to follow up with the patient if there is a possibility of a skin reaction.
53 Policy:This program is applicable to following x-ray guided procedures:Percutaneous Transluminal AngioplastyRadiofrequency Cardiac Catheter AblationVascular EmbolizationStent and Filter PlacementThrombolytic & Fibrinolytic ProceduresPercutaneous Transhepatic Cholangiography and/or Biliary Drainage
54 Policy (continued): Endoscopic Retrograde Cholangiopancreatography Transjugular Intrahepatic Portosystemic ShuntPercutaneous NephrostomyUrinary/Biliary Stone RemovalOrAny other x-ray guided procedure that couldexpose the same area of the skin for morethan 30 minutes
55 Policy (continued):For such cases, the patient must be informed in writing prior to the procedure of the risks associated with large x-ray skin doses.Appropriate follow up must be made, if after completion of a procedure, a large skin dose is possible.
56 Policy (continued):Connective tissue diseases (e.g. scleroderma, lupus erythematosus, mixed connective tissue disease), diabetes mellitus, hyperthyroidism and the homozygous form of ataxia telangiectasia have been associated with an increased sensitivity to radiation. Some chemotherapy agents are also known to increase radiation effects. To avoid injuries when using an oblique or lateral beam projection, the patient's arm must be secured away from the primary beam. Direct exposure of the female breast, especially entrance-beam exposure, must also be avoided.
60 Radiosensitivity of Cells 1 As cells mature they become less sensitive to radiationAs metabolic rate increases cells become more sensitive to radiationAs reproductive rate increases cells become more sensitive to radiationCell types that are most sensitive to radiation include lymphocytes and stem cellsCell types that are least sensitive to radiation include muscle and ganglion cells1 Adapted from The 1906 Law of Bergonie and Tribondeau
61 Various degrees of sensitivity to radiation exist due to the type of tissue which receives the exposureRadiosensitiveRadioresistantBreast tissueHeart tissueBone marrow cellsLarge arteriesMucosa lining of small intestinesLarge veinsSebaceous (fat) glands of skinMature blood cellsImmune response cellsNeuronsAll stem cell populationsMuscle cellsLymphocytes
63 Stochastic Effects (by chance) Health effects that occur randomly. Effects that occur by chance, generally occurring without a threshold level of dose, whose probability is proportional to the dose and whose severity is independent of the dose. .(examples: cancer incidence and genetic effects)
64 Stochastic Effects (by chance) 1,000,000 persons buy a lottery ticket for $1,00 each.999,999 persons will not get the large prize. Only one will win the BIG ONE.Return on scratch tickets is not certain.
65 Nonstochastic (Deterministic) Effects Health effects that can be induced upon reaching an apparent threshold, and their severity varies with the radiation dose.examples:cataract in the lens of the eye, non- malignant damage to the skin
66 Nonstochastic (Deterministic) Effects 100 persons invest $1,000 at 5% interestEach person will receive $1,050.00Return is certain
67 So....., how really dangerous is this so called “RADIATION??”
70 An example of a skin injury attributable to x-rays from fluoroscopy is shown in Figure 2. This case, patient A in Table 2, is that of a 40-year-old male who underwent coronary angiography, coronary angioplasty and a second angiography procedure due to complications, followed by a coronary artery by-pass graft, all on March 29, 1990.Source:Thomas B. Shope, Ph.D. (HFZ-140) FDA/Center for Devices and Radiological Health
71 Figure 2(a).Condition of patient's back six to eight weeks following multiple coronary angiography and angioplasty proceduresSource:Thomas B. Shope, Ph.D. (HFZ-140) FDA/Center for Devices and Radiological Health
72 Figure 2(b).Appearance of skin injury approximately 16 to 21 weeks following the procedures with small ulcerated area present.Source:Thomas B. Shope, Ph.D. (HFZ-140) FDA/Center for Devices and Radiological Health
73 Figure 2(c).Appearance of skin injury approximately 18 to 21 months following procedures, evidencing tissue necrosis.Source:Thomas B. Shope, Ph.D. (HFZ-140) FDA/Center for Devices and Radiological Health
74 Close-up view of lesion shown in 2(c). Figure 2(d).Close-up view of lesion shown in 2(c).Source:Thomas B. Shope, Ph.D. (HFZ-140) FDA/Center for Devices and Radiological Health
75 Appearance of patient's back following skin grafting procedure. Figure 2(e).Appearance of patient's back following skin grafting procedure.Source:Thomas B. Shope, Ph.D. (HFZ-140) FDA/Center for Devices and Radiological Health
76 Transjugular Intrahepatic Portosystemic Shunt 6 month23 month10 month22 monthThis patient received 3 TIPS procedures within a week7.5 monthSource:Koening, Wagner, et al., University of Texas Health Science Center
77 Radiofrequency Cardiac Catheter Ablation Tissue necrosis 5 months after procedure, and deep ulceration with exposure of the humerus at 6.5 monthsSource:Koening, Wagner, et al., University of Texas Health Science Center
78 Radiation-sensitive patients Both patients with Discoid Lupus Erythematosis received skin doses believed insufficient to cause such effects in normal skin.Reproduced with permission from Gironet et al, 1998, Ann Dermatol Venerol, 125,Reproduced with permission from Wagner et al, 1999, Radiology, 213,Courtesy of IAEAIn right photo, G = graft, R = rib
79 Lessons from injured patients Case #1:Electrophysiological and ablation procedureThree attempts in 4 months, each with more than 100 minutes of fluoroscopy.After first attempt erythema observed by patient, but not recognized as due to procedure.Erythemas on back healed. Arm lesion required grafting.Material used here previously copyrighted by Louis K Wagner 2004 or Partners in Radiation Management LTD Company 2004 and used here by permission.Courtesy of IAEA
80 Lessons from injured patients If cause of initial erythemas was correctly identified, injury would likely have been avoided because failures of initial ablations would not have been blamed on faulty equipment.Erythemas on back healed. Arm lesion required grafting.Material used here previously copyrighted by Louis K Wagner 2004 or Partners in Radiation Management LTD Company 2004 and used here by permission.Courtesy of IAEA
81 Lessons from injured patients Case #2:PTCA and stent placement of RCA. Involved 63 minutes of fluoroscopy and nearly 5000 frames of cine in LAO orientation with cranial tilt.Lesion required grafting.Material used here previously copyrighted by Louis K Wagner 2004 or Partners in Radiation Management LTD Company 2004 and used here by permission.Courtesy of IAEA
82 Lessons from injured patients Case #2:Dose buildup due to long fluoroscopy and fluorography with steep angle through thick chested patient not recognizedLesion required grafting.Material used here previously copyrighted by Louis K Wagner 2004 or Partners in Radiation Management LTD Company 2004 and used here by permission.Courtesy of IAEA
83 Lessons from injured patients Case #2:Cause of injury initially misidentified as pressure wound due to defibrillator pad.Lesion required grafting.Material used here previously copyrighted by Louis K Wagner 2004 or Partners in Radiation Management LTD Company 2004 and used here by permission.
84 Lessons from injured patients Case #3:PTCA : 51 minutes high-dose fluoroscopy, 74 seconds cine in 141 kg man. Dose estimated retrospectively at 22 Gy.Lesion required grafting.Courtesy of IAEA
85 Lessons from injured patients Case #3:Cumulative buildup of dose for steeply angled high-dose beam through large patient not recognizedLesion required grafting.Courtesy of IAEA
86 If you use too much radiation … you will get your ass in trouble RULE 1Courtesy of IAEA
87 Excess radiation can sneak up on you and catch you unaware RULE 2 A fluoroscope can bea dangerous beastCourtesy of IAEA
88 Use all protective measures at your disposal to minimize risk Rule 3Use all protective measures at your disposal to minimize risk