Protection Against Medical Exposure IAEA International Atomic Energy

Protection Against Medical Exposure IAEA International Atomic Energy Agency Day 9 – Lecture 4

Objective To provide an understanding of medical radiation protection requirements and to provide an understanding of the basic principles of optimization and justification for medical practices as related to patient doses IAEA 2

Contents • • Responsibilities for protection and safety Responsibilities for protection of patients Justification. Optimization. Considerations for pregnant, and lactating women Release of patients after radionuclide therapy. Unintended and accidental medical exposures Reviews and records IAEA 3

Persons involved in a radiation protection programme • • • Registrants or Licensees; Employers; Radiological Medical Practitioners; Suppliers of Sources and Equipment; Radiation Protection Officers; Referring Medical Practitioners; Medical Physicists; Medical Radiation Technologists; Qualified Experts; Workers; Ethics Committees. IAEA 4

Responsibilities for Protection and Safety • Prime Responsibility: Person (or organization) responsible for the facility or activity; • Establishment and implementation of protection and safety programme: • Registrants or licensees; • Employers (occupational exposure); • Radiological medical practitioners (medical exposure). IAEA 5

Prime Responsibility • The registrant or licensee has a responsibility to ensure that a radiation protection program is prepared and implemented. • Is responsible for radiation protection and compliance with the legislation, regulations and other requirements imposed by the Regulatory Body. • Some responsibilities may be delegated but the registrant and licensee remains ultimately responsible. IAEA 6

Responsibilities The Radiological Medical Practitioner: • must take responsibility for protection and safety in the planning and delivery of medical exposures including justification and optimization in in cooperation with the Medical Physicist and the Medical Radiation Technologist IAEA 7

Responsibilities (cont) Qualified Experts • The registrants or licensees must obtain the services of qualified experts (a suitably experienced medical physicist). • The training, competencies and certification of experts is usually a national matter. The Regulatory Body should cooperate with relevant professional organizations in the recognition of such experts. • Professional organizations would be expected to take a lead in defining work practices, certification and accreditation. IAEA 8

Responsibilities (cont) Qualified expert • “An individual who, by virtue of certification by appropriate boards or societies, professional licences or academic qualifications and experience, is duly recognized as having expertise in a relevant field of specialization, e. g. medical physics, radiation protection, occupational health, fire safety, quality management or any relevant engineering or safety specialty. . ” GSR Part 3 (Definitions) IAEA 9

Responsibilities (cont) The Radiation Protection Officer: • is a person who is technically competent to provide advice and oversight of the local radiation safety programme. • is a crucial component of the radiation safety programme and requires appropriate resources and administrative authority; • “A person technically competent in radiation protection matters relevant for a given type of practice who is designated by the registrant, licensee or employer to oversee the application of relevant requirements” (GSR Part 3 Definitions) IAEA 10

Responsibilities (cont) Radiation Protection Officer (cont): The role of the RPO is determined locally, but typically includes: • responsibility for designation of controlled and supervised areas; • responsibility for ensuring preparation of local rules; • training of new staff in safe radiation work practices; • liaison with the Regulatory Body on radiation protection matters. IAEA 11

Responsibilities (cont) Radiation Protection Officer (cont) The role of the RPO is determined locally, but typically includes: • supervision of the personnel monitoring program; • maintenance of records, especially worker radiation histories; • routine surveillance of radiation areas; • responding to and investigating radiation accidents; • provision of radiation dosimetry; • general advice to the licensee and staff regarding radiation safety. IAEA 12

Responsibilities (cont) Suppliers of Sources and Equipment: a) Supplying a safe radiation generator or radioactive source and device meeting quality standards radiation generators and radioactive sources are tested to demonstrate b) Ensuring that are tested to demonstrate compliance with the relevant specifications; c) Making information available including performance specifications, instructions for operating and maintenance, and instructions for protection and safety; d) Ensuring that the protection provided by shielding and other protective devices is optimized. IAEA 13

Protecting the Patient from what? • Unnecessary examination or treatment (justification). • Unnecessary exposure (optimization). • Inadequate examinations which can lead to an incorrect or an incomplete diagnosis (optimization). • Establishment of Reference Levels IAEA 14

Responsibilities regarding Protection of Patients • “The government shall ensure that relevant parties are authorized to assume their responsibilities and that diagnostic reference levels, dose constraints, and criteria and guidelines for the release of patients are established. . . ” ( GSR Part 3, Req. 34) • "The regulatory body shall require that health professionals with responsibilities for medical exposure are specialized and that meet the requirements for education, training and competence. . . ” ( GSR Part 3, Req. 35) • “Registrants and licensees shall ensure that no person incurs a medical exposure unless there has been an appropriate referral, responsibility has been assumed for ensuring protection and safety, and the person has been informed of the expected benefits and risks. . . ” ( GSR Part 3, Req. 36) IAEA 15

Responsibilities regarding Protection of Patients (cont) Registrants and licensees shall ensure that: • all medical exposures are prescribed by a medical practitioner; • a medical practitioner is assigned responsibility for ensuring overall patient protection in the prescription and delivery of medical radiation exposures; • medical and other paramedical personnel have appropriate training to discharge their tasks in the conduct of the diagnostic or therapeutic procedure that the medical practitioner prescribes; IAEA 16

Radiological Medical Practitioner (Definition: GSR Part 3 Glossary) A health professional with specialist education and training in the medical uses of radiation, who is competent to perform independently or to oversee procedures involving medical exposure in a given specialty. Competence of persons is normally assessed by the State by having a formal mechanism for registration, accreditation or certification of radiological medical practitioners in the given specialty (e. g. radiology, radiation therapy, nuclear medicine, dentistry, cardiology, etc. ). States that have yet to develop such a mechanism need to assess the education, training and competence of any individual proposed by the licensee to act as a radiological medical practitioner and to decide, on the basis either of international standards or standards of a State where such a system exists, whether such an individual can undertake the functions of a radiological medical practitioner, within the required specialty IAEA 17

Health Professional (Definition: GSR Part 3 Glossary) An individual who: has been formally recognized through appropriate national procedures to practise a profession related to health e. g. IAEA 18

Justification of Medical Exposure “Relevant parties shall ensure that medical exposures are justified. ” (GSR Part 3, Requirement 37) • “Medical exposures shall be justified by weighing the expected diagnostic or therapeutic benefits that they yield against the radiation detriment that they might cause, account taken of the benefits and risks of available alternative techniques that do not involve medical exposure. ” (GSR Part 3, 3. 154 ) Dose limits do not apply to medical exposures IAEA 19

Justification (cont. ) • • • “Generic justification of a radiological procedure shall be carried out and shall be reviewed from time to time, with account taken of advances in knowledge and technological developments…” (GSR Part 3, 3. 155) “The justification of medical exposure for an individual patient shall be carried out through consultation between the radiological medical practitioner and the referring medical practitioner, with account taken for patients pregnant, breastfeeding or paediatric…” (GSR Part 3, 3. 156) “Relevant referral guidelines shall be taken into account for the justification of the medical exposure of an individual patient in a radiological procedure…” (GSR Part 3, 3. 157) IAEA 20

Optimization “Registrants and licensees and radiological medical practitioners shall ensure that protection and safety is optimized for each medical exposure” (GSR Part 3, Requirement 38) • Design considerations: conformity to IEC and IOS standards ; • Operational considerations: procedures to ensure that: • “the exposure of patients is the minimum necessary to achieve the required diagnostic objective; • the exposure of volumes other than the planning target volume is kept ALARA consistent with delivery of the prescribed dose; • the appropriate radiopharmaceutical with the appropriate activity is selected…” IAEA 21

Optimization (cont) • Calibration (GSR Part 3, 3. 166): • “In terms of quantities using accepted protocols; • At the time of commissioning, after a maintenance procedure, and at intervals approved by the Regulatory Body; • Calibrations of radiotherapy units are object of to independent verification; • Traceable to a standards dosimetry laboratory…” • Radiopharmaceuticals are calibrated in terms of the activity to be administered IAEA 22

Optimization (cont) • Dosimetry of Patients (GSR Part 3, 3. 167): a) “Diagnostic medical exposures: typical doses to patients for common radiological procedures; b) For image guided interventional procedures, typical doses to patients; c) For therapeutic medical exposures, absorbed doses to the tissues or organs for individual patients…” IAEA 23

Optimization (cont) • Diagnostic Reference levels: “The government shall ensure that diagnostic reference levels for medical imaging are established. ” (GSR Part 3, 3. 168) “Registrants and licensees shall ensure that: a) Local assessments for radiological procedures for which diagnostic reference levels have been established; b) Review to determine whether the optimization of protection is adequate or corrective action is required if: typical doses exceed the diagnostic reference level; or fall substantially below them and the exposures do not provide useful diagnostic information or do not yield medical benefit to the patient. ” IAEA 24

Optimization (cont) Quality Assurance for medical exposure A Quality Assurance program for medical exposures shall be established and shall include: • periodical measurement of the physical parameters of radiation generators, imaging devices and irradiation installations; • verification of the physical and clinical factors used in patient diagnosis and treatment; • written records of relevant procedures and results; • verification of calibration; • independent quality audits. IAEA 25

Optimization (cont) • Dose Constraints: • “relevant dose constraints used in the optimization of protection for carers or comforters. (GSR Part 3, 3. 172) • dose constraints approved by the ethics committee, or by another institutional body that has been assigned similar functions by the relevant authority, on a case by case basis as part of a proposal for biomedical research are used in the optimization of protection and safety for persons subject to exposure as part of a programme of biomedical research…” (GSR Part 3, 3. 173) IAEA 26

Pregnant and breast-feeding women “Registrants and licensees shall ensure that there arrangements in place for appropriate radiation protection in cases where a woman is or might be pregnant or is breast-feeding: ”(GSR Part 3, Requirement 39) Patients who are to undergo x-ray examination of the abdomen, pelvis, lower spine, etc, should be asked whether they are pregnant or if there is a possibility that they might be pregnant. • If yes, the responsible medical practitioner should determine if the examination can be safely deferred. • If no, standard protective measures should nevertheless be applied IAEA 27

Release of Patients after radionuclide therapy “Registrants and licensees shall ensure that there arrangements in place to ensure appropriate radiation protection for members of the public and for family members before a patient is released following radionuclide therapy. ” (GSR Part 3, Requirement 40) “The government shall ensure that criteria for release of patients are established…” (GSR Part 3, 3. 148) “No release of patients shall be done until: (GSR Part 3, 3. 177) a) The activity of radionuclides is such that doses that could be received by members of the public and family members would be in compliance with the requirements set by the relevant authorities. b) The patient is provided with instructions and information on the radiation risks…” IAEA 28

Investigation of Unintended and Accidental Medical Exposures The responsible registrant or llicensee shall promptly investigate incidents such as: • wrong patient subject to diagnostic or therapeutic exposure, wrong organ or tissue exposed, incorrect pharmaceutical used, the radiation dose (or activity) differing substantially from that prescribed or intended; • doses repeatedly and substantially exceeding guidance levels; • repeated failure or other unusual occurrence with potential for causing unintended doses. IAEA 29

Investigation of Unintended and Accidental Medical Exposures (cont) In the event of an accidental exposure, the registrant or licensee shall take action to: • estimate the dose received; • take measures to prevent re-occurrence; • notify the Regulatory Body; • inform the patient and his / her doctor. IAEA 30

Reviews and records “Registrants and licensees shall ensure that radiological reviews are performed periodically at medical radiation facilities and that records are maintained. ” (GSR Part 3, Requirement 42) • Radiological Reviews (GSR Part 3, 3. 181) • Records (GSR Part 3, 3. 182) : • Delegation of responsibilities • Training of personnel • Calibration, dosimetry and quality assurance • Information for retrospective assessment of doses • Reports on investigations of accidental exposures IAEA 31