Radiation Safety in Medicine: Who and How Regulates It, Main Principles, Protection
Everyone wants to be healthy, wealthy and beautiful. This desire is quite natural. It is also natural to feel under weather sometimes and seek medical assistance. The effectiveness of treatment depends entirely on qualitative and timely diagnosis. “Everybody lies except X-ray”. It seems House M.D. said it that way. However, whether diagnosis and treatment are effective and safe at the same time depends to a certain extent on people who take care of radiation safety in medicine. We propose to consider the issue in details.
How is radiation safety regulated? What will happen without regulation?
Due to existing risks and widespread occurrence, which increases every year, the use of radiation sources in medicine requires special and thorough control to protect both patients and personnel. The power of diagnostics and treatment using radiation technologies gradually opens virtually unlimited possibilities for medicine. The greater the power, the greater is the responsibility, which is to adhere to the rules and regulations for the use of radiation.
It is necessary to prove the ability to perform relevant procedures with high quality, ensure protection of patients and comply with legal requirements to receive the permission for any activities with the use of radiation sources in medicine. In addition, the qualification of medical and technical personnel who perform procedures of diagnostic or therapeutic medical exposure has to be sufficiently high. The annual verification of equipment by metrology services, the availability of the quality assurance system for radiation diagnostics or treatment, certification of X-ray and radionuclide diagnostic and radiotherapeutic equipment, radiopharmaceuticals, as well as radiation diagnostic and therapeutic methods are also included into the list of documents required for obtaining permission for activities with radiation sources.
The authorizing documents are developed by two authorities: services of the Ministry of Health of Ukraine issuing health and safety certificate (currently, this function is performed by the State Service of Ukraine to Food Safety and Consumer Protection) and the State Nuclear Regulatory Inspectorate of Ukraine (SNRIU), one of the tasks of which is licensing for the right to use or produce radiation sources. The health and safety certificate is issued for two years, after which it is again necessary to prove the ability to comply with the requirements of the legislation when providing diagnostic or therapeutic services. The SNRIU license is issued depending on the decision of the licensing commission, usually for three years. Upon expiration, the license can be renewed or canceled (if there are serious mistakes in the activities of the organization). In the absence of a valid license or health and safety certificate, it is prohibited to perform activities with radiation sources. These relevant documents shall be available in any organization that carries out activities with radiation sources and, upon request, can be provided to the patient if he/she has doubts about the quality of the services he/she receives at a medical care institution.
Only equipment that meets the requirements of the State Standards and has a positive opinion of the health and epidemiological review for the use on the territory of Ukraine shall be used for both diagnostic X-ray and radiological studies and radiotherapy. It is prohibited to use equipment with expired life and equipment that has not been tested for radiation safety conditions after maintenance or technical changes.
Specialized subdivisions of regional clinical hospitals (radiation safety services – RSS) carry out radiological and technical surveys of X-ray, radionuclide diagnostics, radiation treatment and radiotherapy rooms at least once every two years.
Dental devices can be considered as an example of the danger of clearance from regulatory control due to the probability of their uncontrolled installation even in residential buildings without any structural and individual protective means, as well as the use of devices without any approved methodologies and qualification of personnel, without metrological checks of equipment and dose control of both the patient and personnel. Due to this situation, taking into account the mass nature of dental radiography, the collective dose of the public, which is not taken into account, may increase. Accordingly, measures cannot be taken to control and reduce it.
Basic principles of radiation safety and its use.
An industry of radiation safety was developed to minimize the harmful effects of radiation on the public. The main objective of such an area is to control the current state of radiation use, collection of information, its systematization and summary.
Three principles of radiation safety in medicine is the optimization (use of the best practices, state-of-the-art equipment, highly qualified personnel), justification (only for proven clinical benefit) and dose limitation (regulation of exposure and use of protection with an understanding of clinical benefit, because receiving the qualitative diagnosis or treatment from the first time is the most important thing).
It is a living organism that is constantly in motion, because there are new fields of application of radiation sources, changes in the types of activities, development of new technologies. There is a lot of new information obtained from radiobiology on the increase or decrease of the harmfulness of a certain activity with the use of radiation. Based on this, one can create rules for managing radiation sources and changing them, if the situation tends to deteriorate or improve.
Ideally, all information collected during years (statistical, practical, etc.) should be reflected in documents regulating radiation safety in medicine. This is what happens to a certain extent. The main documents used in activities with radiation sources both in diagnostics and therapy are the orders of the Ministry of Health and SNRIU.
The aspect of using radiation in diagnostic medicine is the ALARA principle (as low as reasonably achievable), which reminds that even low doses envisage the risk of long-term consequences, therefore all reasonable efforts should be taken so that the doses are even lower that those recommended by law, but without compromising the clinical effect.
This principle is achieved through keeping exposure dose at such low levels, which can be achieved provided the required amount and quality of diagnostic information. The minimum exposure dose for the patient also means that the diagnostic procedure will be performed once with maximum quality. Unreasonable appointment and repeated diagnostic X-ray and radionuclide studies are not permitted. Such X-ray or radiological procedures must by justified by a physician based on medical indications.
Two types of radiation in medicine are as follows: diagnostics and therapy, which are fundamentally different in nature and have different objectives and regulatory mechanisms. ALARA is the main rule for diagnostics, and the effective dose (Sieverts as units of measurement) is the degree of possible risks.
For therapy, the main objective is the treatment effect and the conscious use of radiation to destroy the cells of malignant tumors. The absorbed dose of radiation is the main dosimetric value in radiation therapy, and it is measured in Grays. In limiting the exposure dose in therapy, physicians and physicists are guided only by the maximum permissible level of radiation to the tumor and surrounding organs and tissues. In the maximum dose of exposure to the tumor, which is divided into several fractions, one shall try to achieve as minimal pathological reactions of the healthy tissues as possible, with the knowledge that the priority task is to achieve clinical goals, namely the destruction of malignant formation. When it comes to saving lives, then the associated risks can be neglected for the sake of clinical benefit.
Four categories of persons are distinguished during X-ray and radionuclide studies. There are recommended boundary levels of medical exposure for each of them. These recommended levels of diagnostic medical exposure (X-ray and radionuclide diagnostics) are not medical exposure dose limits. Their objective is to reduce diagnostic exposure of the public. The diagnostic exposure should be assesses on the basis of the relationship between benefit and harm for health in appointing one or another procedure. X-ray diagnostic physicians and radiotherapy experts, so as medical physicists, radiation safety engineers, X-ray technicians are people engaged in medical practice related to human exposure who are responsible for radiation protection in the case of appointed medical exposure and during its performance.
It should always be remembered that the only justification for using radiation in medicine is to carry out qualitative diagnostics and treatment if there are clinical indications.
Radiation protection
Time, distance and shielding are the three main components of radiation protection. The time of exposure should be as minimally possible, and the distance to the source should be maximally permissible to achieve the clinical result. It is also necessary to use radiation protection means (shields, screens, protection of equipment, individual protective means) in any situation, if it does not prevent diagnostics or treatment. Radiation protection activities can be divided into two stages: in the design of rooms with radiation sources and directly in the conduct of medical procedures.
1. Design
In the design of rooms, one should calculate protection of premises and buildings according to the rules prescribed by the law. The rooms designed respectively can significantly reduce the release of radiation outside. After setting up the room, once every two years (at least), the radiation safety service should inspect the existing protection using special measuring devices. The results of such inspections and compliance of the protection and design peculiarities of the rooms with the current legislation are monitored in Ukraine by several independent organization to ensure maximum protection of the public from the effects of radiation.
According to Article 40 of the Law of Ukraine “On Nuclear Energy Use and Radiation Safety” and “General Radiation Safety Rules for the Use of Radiation Sources in Medicine”, the design documents for the placement of medical radiological equipment upon commissioning a new facility of the reconstruction of an existing room shall be subject to a state review of nuclear and radiation safety.
The main objective of the state review is to ensure compliance with radiation safety regulations, which means protection of personnel and the public against the harmful effects of medical radiation. It includes comprehensive activities for independent assessment of radiation safety level for human health and the environment.
We asked Tetiana Lytvynska, Deputy Head of Radiation Protection Department of the State Scientific and Technical Center for Nuclear and Radiation Safety (SSTC NRS), a few questions to understand more about the state review procedure:
– Tetiana, who usually develops design documents for the hospitals in Ukraine?
– For medical radiation sources, the activities on the calculation of protection as a part of design documents of departments and rooms of medical institutions are not licensed. Expert in radiotherapy, medical physicist, radiation safety service or even architectural office can perform such activities meaning anybody who mastered relevant methodologies. Thus, the results may be different. The establishment of an institute of certified radiation safety experts in accordance with the European Directive is planned soon, so the activities on the development of designs for the rooms using radiation sources will be transferred to qualified and certified experts. However, even designs of radiation hazardous facilities developed by such experts will be subject to review. After all, nobody is immune to mistakes, which means that double control is needed. The organization that issues licenses needs very strong arguments that the use of radiation sources will be safe as possible.
– What documents should a medical institution provide for the review?
– The following data is obligatory needed for the state review:
- calculation of biological protection of rooms where radiological equipment should be installed or operations with radioactive materials will be performed, including rooms for the management of radioactive waste resulting from the declared activities;
- design technical documents;
- technical documents with technical characteristics of radiological equipment;
- characteristics of available radiation sources.
The main attention is paid to relevant protective measures for equipment in rooms where it is planned to use radiation sources: structure, thickness and protection of walls and doors, presence of a survey window, alarm and interlock system, etc. The focus is on process channels and openings that may weaken the protection and should be appropriately compensated. The documents on the arrangement of the dose monitoring system are also considered as a part of the design. In the course of expert assessment, one checks the consideration of the factors of radiation hazard for different groups of personnel and the public, compliance of equipment characteristics with measured parameters.
– How do medical institutions know where they can make a review?
– In general, the procedure is as follows: according to the Law of Ukraine “On Nuclear Energy Use and Radiation Safety”, the state review of nuclear and radiation safety shall be performed by the state authority for nuclear and radiation safety regulation, namely the SNRIU. For such a review, the applicant shall address the SNRIU Regional Inspection of Nuclear and Radiation Safety according to the territorial belonging during the submitting of documents for performing activities with radiation sources. The Regional Inspections may carry out such a review on their own or, in a corresponding letter, give the initiative to the SSTC NRS, as a responsible expert organization. In turn, the SSTC NRS develops a report for the SNRIU on the made review and provides it with a draft expert opinion, based on which the opinion of the state review of nuclear and radiation safety is presented to the applicant. The SSTC NRS is the only organization with a legal right to perform a state review of nuclear and radiation safety, including design documents for the placement of medical radiological equipment.
– Is this review free?
– No, it is not free. According to Article 40 of the Law of Ukraine “On Nuclear Energy Use and Radiation Safety”, state review of nuclear and radiation safety shall be funded at the expense of the customer of the project. The review procedures are established in the regulation Procedure for State Review of Nuclear and Radiation Safety (NP 306.1.107-2005).
– Have there been cases of negative expert opinions in your practice? What should a hospital do in such a case?
– Yes, such cases are not often, but they sometimes happen. In the case of a negative expert opinion, the customer should revise the design documents for the placement of medical radiation sources according to provided recommendations and submit them to the SNRIU for review. Without a positive review opinion, it is impossible to obtain a license for the right to carry out activities with radiation sources.
– Based on your experience, how would you describe the state of radiation safety in medicine in Ukraine today?
– There are plenty of problems in this area, which include an insufficient instrument base, use of morally and technically obsolete equipment, significant problems in quality control. It is also desirable to have an external audit from the expert organization to check safe operation of departments using radiation sources, which is a standard practice in developed countries. Radiation safety area to a significant extent relies on the enthusiasm of professionals working in this field. Recently, the SNRIU created the Interdepartmental Working Group of Experts on Radiation Protection in Medicine. Among the main tasks is to improve the regulatory framework and take practical measures to ensure radiation protection, improve quality of medical radiation. It would be desirable for these initiatives to receive practical support from the state and from the medical community.
2.Medical procedures.
Protection in the conduct of medical procedures using radiation is ensured by the right choice of modes of equipment operation or relevant activity of radionuclides, precisely calculated dose and qualitatively made planning.
In the X-ray examination, it is obligatory to perform shielding of genital organs, thyroid gland and eyes of patients, if this does not prevent the receipt of qualitative diagnostic information. The whole body of children except the area under study shall be shielded and special fixing devices shall be used to exclude the need for help from unauthorized persons. For all types of X-ray studies, the range of exposure field should be minimal, while the procedure should be as short as possible, but not less than the period needed to ensure high quality study.
It should be kept in mind that the use of state-of-the-art equipment, the latest diagnostic and treatment techniques, compliance with all radiation safety rules and regulations can only minimize the negative effects of radiation on the human body. Every patient should know his/her rights. At the same time, both the doctor and the patient should always remember that if selecting between “benefit” and “harm”, they should always choose “benefit” in any medical procedure.
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