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2. Radiation Safety Induction for Radiology Registrars John Saunderson Radiation Protection Adviser TPRH ext 6690 3. Ionising radiations x-rays gamma rays (-rays) beta particles () electron beams Not ionising radiations lasers ultraviolet (UV) infrared (IR) ultrasound MRI Ionising / Non-ionising 4. Part 1 Physics Lectures Basic Physics (4h) Trevor Davies (Nuclear Medicine Physicist) CHH ext 2119 / 2125 Radiation hazards and dosimetry (10h) John Saunderson (Consultant Physicist/Radiation Protection Adviser) PRH ext 6690 Diagnostic radiology (10h) Jenny Wilson (Radiation Physicist) PRH ext 6693 CT (2h) Craig Moore (Radiation Physicist) PRH ext 6808 Radionuclide Imaging (2h) Graham Wright (Nuclear Medicine Physicist) CHH 2125 / 2115 + 9h radiographer sessions Exam 11 Dec 2006 5. Wilhelm Roentgen Discovered X-rays on 8th November 1895 . 6. Frau Roentgens hand, 1895 Colles fracture 1896 . 7. Mihran Kassabian (1870-1910) 8. Dose Reduction Precautions X-ray tubes shielded Collimation Aluminium filters Weekly exposure limits introduced 9. Radiation Effects Acute radiation syndrome Including vomiting, diarrhea, reduction in the number of blood cells, bleeding, epilation (hair loss), temporary sterility in males, and lens opacity (clouding ) Late 1940s Dr Takuso Yamawaki noted an increase in leukaemia 20% of radiation cancers were leukaemia (normal incidence 4%) Incidence peaked at 6-8 years Solid cancers excess seen from 10 years onwards. 10. Early X-ray pioneers Acute effects Precautions introduced Atomic bomb survivors Acute effects similar in nature to pioneers Some increased cancer risk But what about radiology today? 11. Cancer Risk 1 in 20,000 risk of fatal cancer per millisievert Chest x-ray: 0.02mSv 1 in a million risk Abdomen x-ray: 1mSv 1 in 20,000 Barium meal: 3mSv 1 in 7,000 CT abdomen: 10mSv 1 in 2,000 (Typical interventional radiologist dose < 3 mSv/y) Small risk compared to natural cancer risk Why worry? 12. 700 CANCER CASES CAUSED BY X-RAYS X-RAYS used in everyday detection of diseases and broken bones are responsible for about 700 cases of cancer a year, according to the most detailed study to date. The research showed that 0.6 per cent of the 124,000 patients found to have cancer each year can attribute the disease to X-ray exposure. Diagnostic X- rays, which are used in conventional radiography and imaging techniques such as CT scans, are the largest man-made source of radiation exposure to the general population. Although such X-rays provide great benefits, it is generally accepted that their 30 January 2004 Average X-ray examination dose = 0.5mSv 1 in 40,000 risk UK Radiology = 41.5 million X-rays per year 13. Basic Principals of Radiation Protection Justification Benefit > risk Optimisation Doses as low as reasonably achievable Limitation Absolute legal limits for staff and public Reference levels as guidance for patients. 14. Regulations Ionising Radiations Regulations 1999 (IRR99) Local rules, radiation protection supervisors Ionising Radiation (Medical Exposures) Regulations 2000 (IRMER2000) Referrers, practitioners, operators Justification & optimisation Medicines (Administration of Radioactive Substances) Regs 1978 (ARSAC) Nuclear medicine 15. Organising radiation safety Controlled Areas Local Rules Radiation Protection Supervisor Radiation Protection Adviser Radiographer. 16. IRMER Ionising Radiation (Medical Exposures) Regulations 2000 Referrers allowed to request medical exposure Trust decides who can e.g. GP, consultant, etc. Practitioners Justifies X-ray - decides there is net benefit Trust decides who can e.g. radiologist Operator Performs practical aspects Trust decides who can e.g. radiographer, technician . 17. 19 Medicines (Administration of Radioactive Substances) Regs 1978 (MARS / ARSAC) No person shall administer to a human being (otherwise than to himself) any radioactive medicinal product unless he is doctor or dentist holding a certificate issued by the Health Minister for the purposes of section 60 of the Act in respect of radioactive medicinal products (hereinafter referred to as a certificate) or a person acting in accordance with the directions of such a doctor or dentist. . 18. Radiation in hospitals Radioactive substances nuclear medicine pathology radiotherapy X-ray sources Radiology Radiotherapy Pathology . 19. X-ray tube Primary beam Scattered radiation Patient Leakage 20. Basic Principles Time Distance Shielding 21. Distance Double distance = 1 /4 dose Triple distance = 1 /9 th dose. 22. Shielding 23. Shielding 24. Typical Transmission through Shielding (90 kV) 0.25 mm lead rubber apron 8.5% 0.35 mm lead rubber apron 5% 2 x 0.25 mm apron 2.5% 2 x 0.35 mm apron 1.0% Double brick wall 0.003% Plasterboard stud wall 32% Solid wooden 1 door 81% Code 3 lead (1.3 mm) 0.1%. 25. Lead Apron Storage Always return to hanger Do not fold dump on floor and run trolleys over the top of them!!! X-ray will check annually But if visibly damaged, ask X-ray to check them. 26. First Physics lectures Tuesday 12 September 2pm start (please be prompt) The Princess Royal Hospital, Saltshouse Road 27. The End