6IR(ME)RIn 1997 the Council of the European Union (EU) issued a directive that came into forcein the United Kingdom on 13 May 2000 through the provisions of the IonisingRadiation (Medical Exposure) Regulations 2000 [IR(ME)R].
7Purpose of the Directive: Protection of individuals in relation to radiographic exposure as part of their:Medical DiagnosisTreatmentOccupational health surveillanceHealth screeningResearchMedico-legal procedures
10Employer (NHS Trust/Chiropractic Clinic) Identify and record duty holdersRPA (Radiation Protection Advisor)RPS (Radiation Protection Supervisor)Ensure appropriate education, training and supervision of staffEstablishing referral criteria and systems for justifying examinations/proceduresWritten protocols for every standard examination of equipment (e.g. reference levels (DRL’s)Assessment of patient doseInvestigate incidents
11Referrer Responsible for providing clinical reasons for the requested examination/s.Decisions on who is entitled to act as a referrer should be taken at local level by agreement between the employer and the healthcare professionals involved in medical exposures.The range of procedures that can be requested by a referrer should be agreed locally between the referrer and the employer of the radiological installation.
12PractitionerDecisions on who is entitled to act as a practitioner should be taken at local level by agreement between the employer and the healthcare professionals involved in medical exposures.The primary responsibility of the practitioner is to JUSTIFY medical exposures. This requires the practitioner to have a full knowledge of the potential benefit and detriment associated with the procedure under consideration.
13OperatorAn operator is anyone who carries out a “practical aspect”.The range of functions covered by this term isextensive and includes the supporting functions prior tothe exposure taking place (e.g. the calibration of equipment that emits ionising radiation, the preparation ofradioactive medicinal products etc), as well as of performing the exposure itself.
14Duty Holders Is there always a referrer? Can individuals fulfill more than one role?
16Justification2.1. The Medical Exposures Directive requires that all medical exposures to ionising radiation must be justified prior to the exposure being made.Risk/Benefit:The benefit of the radiation exposure should be greaterthan the risk of using it.When applied directly to the exposure of patients;each particular medical practice in a department must bejustified twofold:As a general procedure (IRR 99)As regards the individual patient (IR(ME)R 2000
18Justification & Pregnancy “28 day rule” for routine radiographic examinations“10 day rule” for high-dose procedures, such as bariumenemas, abdominal or pelvic CT, and Nuclear MedicineSpecial case where individual justification is needed
1928 Day Rule:Menstrual cycle varies, generally 28 days. If patient is to be exposed to ionising radiation for diagnostic purposes and the patient is of child-bearing age, postpone exposure for 28 days from first day of menstrual cycle to next to rule out pregnancy.10 Day Rule:If patient is to be exposed to ionising radiation for diagnostic purposes If patient is to be exposed to ionising radiation for diagnostic purposes and the patient is of child-bearing age, she should be booked in the first 10 days of the menstrual cycle, when conception is unlikely to have occurred.
20Advice from National Radiological Protection Board: Radiation doses resulting from most diagnostic procedures in an individual pregnancy present no substantial risk ofcausing fetal death or malformation or impairment of mental development.Procedures giving the greatest foetal exposure are:Barium EnemasPelvic and Abdominal CT scansNuclear Medicine[Most sensitive time period for CNS teratogenesis is between 10-17weeks.]
21Special Cases:A patient at 19 weeks of gestation presented with flank pain and microscopic hematuria. She was diagnosed with pyelonephritis and treated with parenteral antibiotics. Her flank pain progressed despite antibiotic treatment, necessitating a renal ultrasound examination, which was inconclusive. An intravenous pyelogram (IVP) was ordered, but the radiologist refused to perform the study because of concern about radiation exposure to the fetus. Despite further discussion, the study was denied until a perinatologist verified the appropriateness and relative safety of the study.The IVP revealed two stones, and the patient eventually required ureteral stent placement. Despite treatment, she had progressive renal disease with obstruction, requiring induction of labor at 35 weeks of gestation. At birth, her infant was healthy and weighed an age-appropriate 2,500 g (5 lb, 8 oz).
22Justification When might an individual exposure be unjustified? What do you do if an individual falls outside the anticipated selection procedure?What do you do if the patient has been examined radiologically at another hospital recently for the same condition?
23RADIATION PROTECTION 118 “Referral guidelines for imaging” JustificationChief causes of wasteful use of radiology:Repeating investigations which have already been doneInvestigation when results are unlikely to affect patient managementInvestigating too oftenDoing the wrong investigationFailing to provide appropriate clinical information and questions that the imaging investigation should answer.Over-investigating.RADIATION PROTECTION 118 “Referral guidelines for imaging”
24Optimization9.1. Regulation 7 provides for the optimisation process which involves ensuring that doses arising fromexposures are kept as low as reasonably practicable.ALARPReducing number of images taken of a patientDose-reducing equipmentGood techniqueQuality Assurance ProgramAdequate training
25Limitation Legal dose limits for workers and members of the public ensuring that no deterministic effects are produced andprobability of stochastic effects is reasonably low.diagnostic reference levels for each standardradiological investigationStaff: 20mSv per year whole body dose. Not to exceed100mSv over 5 year periodTrainees/Students: 6mSv per year whole body doseMembers of the public/foetus: 1mSv per year