Note 16 Nov 2023 at 3_42_03 PM.pdf

IAEA Standard Syllabus Course on Radiation Protection in Diagnostic and Interventional Radiology RADIATION PROTECTION IN DIAGNOSTIC AND INTERVENTIONAL RADIOLOGY L 0. Principles of Radiation Protection and Motivation for the Course IAEA International Atomic Energy Agency Introduction • • • Subje...

IAEA Standard Syllabus Course on Radiation Protection in Diagnostic and Interventional Radiology RADIATION PROTECTION IN DIAGNOSTIC AND INTERVENTIONAL RADIOLOGY L 0. Principles of Radiation Protection and Motivation for the Course IAEA International Atomic Energy Agency Introduction • • • Subject matter motivation for radioprotection and quality assurance in diagnostic and interventional radiology Give an overview of different contributions of radiation exposure, the principles of radiation protection Specifity of the medical exposure IAEA Introduction to Radiation Protection in Diagnostic Radiology 0 Is there RADIATION in this room? IAEA Introduction to Radiation Protection in Diagnostic Radiology 0 Radiation - We live with Food Radioactive levels (Bq/kg) Daily intake Ra-226 (g/d) Rice Wheat Pulses Th-228 Pb-210 K-40 150 270 60 0.126 0.296 0.233 0.267 0.270 0.093 0.133 0.133 0.115 62.4 142.2 397.0 Other Vegetables 70 0.126 0.167 -- 135.2 Leafy Vegetables 15 0.267 0.326 -- 89.1 Milk 90 -- -- -- 38.1 1370 0.067 0.089 0.063 65.0 Composite Diet IAEA Dose equivalent=0.315 mSv/yr Total dose from Natural sources = 1.0 to 3.0 mSv/yr Introduction to Radiation Protection in Diagnostic Radiology 0 Radiation from Natural Sources • • Normally 1-3 mSv/year In areas of high background, 3-13 mSv/year Imp IAEA Introduction to Radiation Protection in Diagnostic Radiology 0 Lethal Dose= 4Gy X ray LD 50/60 = 4 Gy For man of 70 kg Energy absorbed = 4 x 70 = 280 Joules = 280/418= 67 calories = 1 sip IAEA Introduction to Radiation Protection in Diagnostic Radiology 0 SO WE NEED RADIATION PROTECTION IAEA Introduction to Radiation Protection in Diagnostic Radiology 0 Radiatio n We live with 1-3 mSv Can kill 4000 mSv Where to stop, where is the safe point? What are the effects of radiation? IAEA Introduction to Radiation Protection in Diagnostic Radiology 0 What can radiation do? Death Cancer Skin Burns Cataract Infertility Genetic effects IAEA Introduction to Radiation Protection in Diagnostic Radiology 0 CAN X RAYS CAUSE DEATH? IAEA Introduction to Radiation Protection in Diagnostic Radiology 0 OBJECTIVES OF RADIATION PROTECTION • • PREVENTION of deterministic effect LIMITING the probability of stochastic effect HOW? Up to what point? IAEA Introduction to Radiation Protection in Diagnostic Radiology 0 Optimization • • • • Optimization balances diagnostic image quality with dose to the patient. High dose >> High image quality Low dose may imply low image quality However, there are a range of doses where image quality is clinically acceptable– want to be in that range IAEA Introduction to Radiation Protection in Diagnostic Radiology 0 Optimizaiton • • Optimization is not ALARA A certain amount of radiation is needed to provide the clinical image quality necessary for diagnostic purposes IAEA Introduction to Radiation Protection in Diagnostic Radiology 0 Which Exposure is Optimum? 6 3 6.0 mGy 1.5 mGy IAEA Little difference in noise between 6 and 3 mGy, therefore 6 mGy is too high. 0.6 mGy too noisy. Optimum between 1.5 and 3.0 mGy. 3.0 mGy 1.5 0.6 mGy 0.6 Introduction to Radiation Protection in Diagnostic Radiology 0 in IAEA PRINCIPLES OF RADIATION PROTECTION Introduction to Radiation Protection in Diagnostic Radiology 0 1. 2. im Justification of practices Optimization of protection by 2 keeping exposure as low as reasonably achievable 3. 3 Dose limits for occupational 1 IAEA Introduction to Radiation Protection in Diagnostic Radiology 0 Radiation ON Time Workload=100 exposures/day e CxR = 50x50 m sec = 2500 = 2.5 LS = 50x800 m sec = 40000=40s Total time = 45 sec/day Not greater than 1 min/day IAEA Introduction to Radiation Protection in Diagnostic Radiology 0 Staff Doses Dose limit ICRP = 20 mSv/yr. Radiography work 0.1 mS/yr. i.e. 1/200th of dose limit IAEA Introduction to Radiation Protection in Diagnostic Radiology 0 FLUOROSCOP Y AND CT IAEA Introduction to Radiation Protection in Diagnostic Radiology 0 Fluoroscopy and CT Barium study: 3-6 min/pt x 8 patients/d =40 min/d ANGIOGRAPHY • Diagnostic = 50 min/d • Therapeutic = 2-5 hr/d CT = 10-45 min/d IAEA Introduction to Radiation Protection in Diagnostic Radiology 0 Fluoroscopy (excl. inv angio) Risk of Death Skin burn Infertility Cataract Cancer Genetic effect Staff No No No No U U Patien t No No No No U U Publi c No No No No U U U: unlikely IAEA Introduction to Radiation Protection in Diagnostic Radiology 0