Contrôle review n°172 - Improving patient radiation protection in medical practices

Published on 15/09/2006

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A number of severe radiation protection accidents have occurred in France in recent months in radiotherapy departments, resulting in serious pathologies among the exposed patients and the death of one person. These accidents, allied to the fact that use of ionising radiation for medical purposes is the leading source of human exposure, justify the priority the ASN gives to radiation protection of patients and its supervision. With the ASN's transposition of Directive 97/43/Euratom concerning patient exposure to ionising radiation, France has for the first time a specific regulatory framework incorporated into the Public Health Code. What can be said about the radiation protection situation of patients in France in 2006? I am pleased to see learned societies working alongside the ASN in drafting the various medical indication and procedure guides promoted by the regulations, which should eventually lead to progress in the justification of procedures and reduce the resulting exposure. More recently, the training actions required by the regulations and which are necessary if the radiation protection culture is to move forward, began to expand towards in the various categories of health care personnel concerned. The ASN has also gradually incorporated a patient radiation protection item into its medical installations supervision program. ASN staff periodically carry out checks to assess the availability and appropriateness of the means needed to implement these new regulations. These checks lead me to the conclusion that, particularly in conventional radiology, the means for improving knowledge of actual patient exposure and organising the collection of data and their transmission to the IRSN are not always available and that the resources devoted to medical radiophysics in the establishments are as yet unable to cover all the new duties entrusted to persons specialising in medical radiophysics (PSRPM) since November 2004. Finally, the extremely rapid development in recent years of new medical imaging technologies, whether or not associated with radiotherapy or nuclear medicine techniques, warrants particularly close attention, owing to the possible rise in the ionising radiation doses delivered to the patients. Progress is therefore still necessary in order to improve patient radiation protection, in particular within health care establishments. Aside from its own supervisory role and the powers of inspection recently granted to it, the ASN must however establish effective cooperation with the organisations in charge of the health care establishments, to examine ways and means of enhancing the material resources given to radiation protection whenever necessary, and of course alert them if patient safety were to be threatened. This is already a goal for the new ASN, which is now becoming an independent authority. For better patient radiation protection, I would finally like to see the ASN develop close links with all health safety stakeholders, whether in charge of equipment planning (regional hospitalisation agencies, national cancer institute), assessing medical practices (High Health Authority) or specific supervision actions (Afssaps).

André-Claude Lacoste

Actions of the Nuclear Safety Authority in the field of patients radiation protection# The elaboration of the national regulation related to the radiation protection of patients has been completed at the end of 2004. For the Nuclear Safety Authority (ASN), in charge of the control, this topic is still a new issue. However, it is yet integrated within its annual inspection program. ASN has to maintain vigilance and to be very determined about all possible causes which could lead to deterministic effects for the patients, in particular in radiotherapy. In parallel, ASN has planned several actions in collaboration with public bodies in order to improve the integration of radiation protection of patients in medical practices, to increase means assigned to this specific issue, particularly for radiophysic, and to develop supervision actions in order to estimate patients exposures.#2 Supervision and evaluation of patient radiation protection in Belgium: organisation, challenges and perspectives for the future# Based on the specificities of medical exposures, on national statistics, on the principles governing the organisation and the assessment of the radiological protection of patients in Belgium today as well as on their field experience, the authors present a first analysis including challenges and perspectives for the future. Their main conclusion is that an appropriate radiation protection system for the patients cannot be assured by the proper use of a well designed inspection system alone. It requires collaborative efforts, involvement of stakeholders from the medical field and creative initiatives from regulatory authorities.#2 Notification of severe adverse events linked to health care: an experience sharing tool helping to improve patient safety# In the field of health care, the occurrence of undesirable events is sometimes considered to be the unavoidable counterpart of its effectiveness and increasing complexity. However, the frequency, severity and avoidable nature of a large proportion of these events led the legislator to require that health professionals declare any undesirable and severe events (EIG) related to health care in the 4 March 2002 law on patients' rights and health system quality. These measures are designed to prevent the recurrence and mitigate the effects of these EIG events whenever possible, through the lessons learned and from analysis of the circumstances in which they occurred. This measure is a part of a broader national policy asserting patients' rights, and developing health care quality and safety, against the background of international support for patient safety improvement actions. In practical terms, the declaration system uses risk management methods based on experience sharing which have proven their effectiveness for many years in the civil aviation and industrial sectors. Implementation of this system, which requires prior experimentation by the French Health Monitoring Institute (InVS), constitutes an opportunity to bring the various supervision and monitoring systems closer together and to develop a patient safety culture.#2 Severe radiotherapy accidents worldwide and their main lessons for the ASN# In 2005 and 2006, two severe radiation therapy accidents were notified to the French Nuclear safety authority (ASN). Radiological accidents due to medical exposures are very rare worldwide in comparison with accidents involving radioactive source for industrial use. However, these accidents may potentially involve a high number of patients. Therefore, it is essential to learn lessons from the past accidents to prevent there occurrence. This paper presents the circumstances of four severe accidents occurred worldwide during the last twenty years, the lessons learned and how the ASN has taken them into account.#2 Radiation protection and radiologists# The French Radiological Society was involved in defining a strategy for implementing quality control of equipment and in drafting the medical indication and procedure guides required by Directive 97/43/Euratom. To ensure that this Directive is successfully applied, the new culture it enshrines must be disseminated among the prescribing physicians. With regard to the traceability of practices and the doses received by the patients, a system for providing detailed information has yet to be set up.#2 The new duties of medical physicists, persons specialised in medical radiophysics (PSRPM) in health structures# The use of ionizing radiation in medicine is currently increasing with technical and technological improvements raising the needs for medical physics competencies. The essential responsibility of the Qualified Medical Physicist's clinical practice is to assure the optimum use of radiation to produce a stated diagnostic or therapeutic outcome. This responsibility includes: protection of the patient and others from potentially harmful or excessive radiation; establishment of adequate protocols to ensure accurate patient dosimetry; the measurement and characterization of radiation; the specification of dose delivered; development and direction of quality assurance programs; and assistance to the practitioner in optimizing the balance between the beneficial and deleterious effects of radiation. It is obvious that these responsibilities imply to define, at the hospital level, an organization of the physics competencies adapted to the clinical practice and activities. This organization must be operational and has to assure its missions in all the clinical departments using ionizing radiation. This is the challenge that French medical physicist will have to face in the very next future.#2 The role of radiopharmacist in radiation protection of the patient# As all other professional using ionising radiations in medicine, the radiopharmacist is obviously concerned about radiation protection of the patient. He contributes to the application of the ALARA principle at different levels, particularly: pharmaceutical analysis of prescription radiopharmaceutical drugs, patient dose and image quality optimization, individual nominative dispensing, preparation of radiopharmaceuticals according to Good Radiopharmacy Practice, quality control of radiopharmaceutical preparations and equipments used, advices for good use of radiopharmaceutical and information for patients.#2 Patient release procedrues after iodine 131 treatment for thyroid cancer# The recommendations to be given to the patient after nuclear medicine treatment with iodine 131 raises numerous questions if one is looking for a balance between a systematic approach (resulting in unjustified constraints in certain patients) and an overly diversified approach (hard to implement as a routine practice). After examining the literature and using simulations based on French data, analysis of the situation shows that protection of the public does not justify particular recommendations, except in a very limited number of cases. With respect to those close to the patient, the recommendations should concentrate on family environments with young children, for dose rates higher than 10 µSv/h (12% of patients treated), and pregnant women, for dose rates higher than 5 µSv/h (30% of patients).#2 Patient information during examinations involving ionising radiation# Informing the patient is a medical duty even when there is no use of ionising radiation involved. In particular in a diagnostic situation, the problem is often to obtain clear information about the potential risks, because one is dealing with “small doses”. It is also hard to situate this risk among all the other inherent risks, in particular those created by the disease itself, without forgetting the anxiety created for the patient by the disease and the nature of the examinations. The risk should be expressed differently in radiology and nuclear medicine. The use of coupled systems (radiology and nuclear medicine) further complicates the problem. The interview with the patient must be structured so as to deal in turn with the nature of the procedure and what is involved, the risks inherent in the radiological but also the non-radiological procedures, resulting in a risk-benefit trade-off. It must however be remembered that the patient is above all expecting to be told about the result of the procedure.#2 The current and future role of imaging in modern medicine# Since more than 30 years, medical imaging technology has invented new machines to explore always more precisely the human body: US, CT, MR, PET. Thanks software and hardware progresses and more specific technique evolution, medical imaging systems allow now to display 2D, 3D & 4D images with anatomic, physiological and molecular information to determine diseases diagnose and apply therapy with its efficiency assessment. This article presents a large overview of these technology and applications trends beneficing patients and modern medicine.#2 New radiotherapy techniques# The use of computer and multifeaf collimator has been the basis of conformal 3D radiotherapy with modern linear accelerator. Innovation remains very active with Intensity Modulation Radiotherapy (IMRT) to treat concave volume and Intraoperative Radiotherapy (IORT). To irradiate mobile targets Image Guided Radiotherapy (IGRT) is becoming popular. New machines as Tomotherapy® and Cyberknife® will have dedicated indication. Hadrontherapy is already using proton beam for eye and base of skull tumors. Carbon Ion Therapy will combine the geographical accuracy of proton and the biological benefit of High LET particles#2 Afssaps's vision of quality assurance# The French Health Products Safety Agency (Afssaps) has started since 2002, a vast program in order to set up quality control of the 50 000 French medical devices emitting ionizing radiations. Afssaps acts in the scope of a French law regulation from 1998 on the reinforcement of health products safety as well as in the scope of the Euratom directive from 1997. This work should be completed before the end of 2007. Afssaps, in close connection with the French Nuclear Safety Authority (DGSNR) and the professional associations, shall then engage a consolidation period.#2 Medical exposure of the French population to ionising radiation: from inventory to implementation of a long-term information system# With the implementation of the European Directive 97/43, the knowledge of medical practices is necessary and the question of the population exposure from medical X-ray examinations is raised. The only nationwide survey on diagnostic medical X-ray examinations was carried out in France more than 15 years ago. Consequently, the Institute for radiation protection and nuclear safety (IRSN) and the National institute for public health surveillance (InVS) collaborated to provide new data. A study was carried out in order to evaluate the nature and frequency of X-ray diagnostic procedures performed in France in 2002 from the data of the main health insurance company (CNAMTS) and the national statistics of the health establishments (SAE). As these two main sources may overlap, a high and a low hypothesis were considered. Doses associated with these examinations were estimated also from the DRL campaign in France and from the British dose data mainly. All diagnostic exams reached between 61.3 and 73.6 millions in 2002 for a per caput effective dose between 0.7 and 0.8 mSv. In the continuity of this study and in light of available data, a new information data system providing perpetual and relevant information about exposure of patient to ionizing radiation in France is now investigated.#2 Diagnostic reference levels# Since March 2004 diagnostic reference levels (DRL) in radiology and nuclear medicine have been implemented in the French regulation. At April 30, 2006 about 50% of the nuclear medicine departments have transmitted there data, 36% concerning bone imaging. In radiology, the data were received from only 73 departments among more than 6000. In nuclear medicine the injected activities for 99mTc radiopharmaceuticals are almost always above the DRLs but for the other radionuclides (123I, 18F…) the DRLs are respected. In radiology, due to the low number of data it was possible to calculate the 75 percentile of entrance dose only for PA chest examination. This value was 0.38 mGy for a DRL of 0.3 mGy.#2 Swiss strategy for setting up of reference levels in diagnostic and interventional radiology# The aim of this article is to present the strategy used in Switzerland to adopt Reference Levels (RL) for diagnostic and interventional radiology. For a number of Radiographic examinations the RLs recommended by the European Commission were adopted. Reference Levels are difficult to establish in the case of X-ray examinations involving fluoroscopy particularly those performed in angiography and interventional radiology due to the large variability between examinations: fluoroscopy duration, number of images, dose. In order to tackle this problem a nation-wide dosimetric survey was performed in Switzerland involving five university hospitals, aiming at establishing a set of RLs for eight types of examinations performed in diagnostic and interventional radiology. Each centre was requested to provide information on the patients and the technical data related to 20 examinations for each type. From the data collected, the distributions of the dose-area product, the number of images and the duration of fluoroscopy were established. A large variability of the technique was found. A set of RL values was then determined using the 3rd-quartile method. In the case of computer tomography the results of the Swiss hospitals from the European study, which was organized in 2003, has been used to establish the RL.#2

Date of last update : 18/01/2014