1. Patient dose management in the International BSS

The new International BSS was published in 2014 [1]. Strong requirements are set to implement into the clinical practice the two basic principles of radiation protection in medical uses of ionizing radiation, namely justification and optimization. If justified and appropriate, the radiological procedure should be performed in such a way that the radiation protection and safety is optimized. The BSS recognise several components of optimization of protection and safety related to medical exposure: design of radiological equipment; calibration of sources and equipment; quality assurance and quality control; dosimetry of patients and use of diagnostic reference levels (DRLs); operational consideration of radiological procedures; dose constraints for carers or comforters, as well as for volunteers in a programme of biomedical research.

For diagnostic radiology and image guided interventional procedures, optimization means that the following are used [1]:

- “Appropriate medical radiological equipment and software, and, for nuclear medicine, appropriate radiopharmaceuticals;

- Appropriate techniques and parameters to deliver a medical exposure of the patient that is the minimum necessary to fulfil the clinical purpose of the radiological procedure, with account taken of relevant norms of acceptable image quality established by relevant professional bodies and of relevant diagnostic reference levels established ...”

Patient dosimetry and DRLs are recognized as important tools for optimization. The term Diagnostic Reference Level is used in the new BSS, in replacement of the previously used “guidance levels”, and is defined as “a level used in medical imaging to indicate whether, in routine conditions, the dose to the patient or the amount of radiopharmaceuticals administered in a specified radiological procedure for medical imaging is unusually high or unusually low for that procedure”. The BSS set to the government responsibilities for the establishment of DRLs: “The government shall ensure that as a result of consultation between the health authority, relevant professional bodies and the regulatory body, a set of DRLs is established for medical exposures incurred in medical imaging, including image guided interventional procedures. In setting such DRLs, account shall be taken of the need for adequate image quality…. Such diagnostic reference levels shall be based, as far as possible, on wide scale surveys or on published values that are appropriate for the local circumstances.”

The new BSS does not provide numerical values of DRLs. As the clinical practice and medical imaging technology may vary between countries, DRLs should be established preferably at a national level to reflect the national practice, or by combining efforts in a group of countries or a region with similar health care settings. The imaging procedures, for which DRLs are to be established, should be decided upon at national or regional level. They should also reflect the typical practice in the country.

The established DRLs should be used for benchmarking of practice in radiological facilities. As stated in the BSS, “Periodic assessments are performed of typical doses or activity of the radiopharmaceuticals administered in a medical facility. If comparison with established DRLs shows that the typical doses or activity of the radiopharmaceuticals administered are either too high or unusually low, a local review is to be initiated to ascertain whether protection and safety have been optimized and whether any corrective action is required” [1].

2. IAEA guidelines for practical implementation of the BSS requirements

A number of IAEA Safety Reports were published in last decade addressing radiation protection in existing and newly emerging technologies, like interventional procedures; cardiac CT; CT colonography, PET/CT, paediatric radiology, etc. [3-7].

Under development is a new Safety Guide on Radiation Protection and Safety in Medical Uses of Ionizing Radiation, prepared jointly by the IAEA, the WHO, the PAHO and the ILO, that provides guidance for end-users in medical radiation facilities. The Safety Guide is expected to be finally approved and published in 2016. The Safety Guide provides more detailed guidance on setting and use of DRLs and the review cycle. The optimization process in a radiology department should start with local assessments of typical doses at approved intervals for those radiological procedures for which DRL have been established (Fig. 2). Local review and optimization should be performed by the radiological medical practitioner, in collaboration with the medical radiation technologist and the medical physicist, as well as the radiopharmacist or radiochemist in the case of diagnostic nuclear medicine. A review should be conducted to determine whether the optimization of protection and safety for patients is adequate, or whether corrective action might be required if, for a given radiological procedure typical doses or activities exceed the relevant DRL, or they fall substantially below the relevant DRL and the exposures do not provide useful diagnostic information or do not yield the expected medical benefit to the patient. Records should be made of local assessments and reviews made with regard to DRLs. Special focus is made on optimization of procedures for paediatric patients subject to medical exposure that requires paediatric DRLs to be also established. Optimization requires teamwork of the radiological medical practitioner, the medical radiation technologist and the medical physicist.This cycle of establishment of national or regional DRLs, use by imaging facilities, corrective actions by imaging facilities, and periodic review of national or regional DRLs brings about a steady improvement in optimization of protection and safety across the country or region.

A meeting on implementation of the new Safety Guide was conducted by the IAEA in November 2016. More than 50 representatives of IAEA Member States participated and exchanged their experiences, implementation approaches and good practices. The meeting concluded on the need of following actions:

- Support regional and national action plans to respond to the requirements of the BSS in medical area, particularly when no centralised regulatory body is empowered or authority is distributed across multiple bodies;

- Organize workshops with decision makers from Regulatory bodies and Health authorities combined on a regional/ subregional basis, to promote organizational coordination, their roles, responsibilities, staffing and qualification;

- Strengthen collaboration in education, training and technical support for all professionals and all modalities. Particularly, address the lack of training, both theoretical and practical, for the assessment of the specification, operation and performance of multimodality platforms and new technologies for all professionals;

- Provide guidance on management of workers, patients and carers who are or might be pregnant.

3. IAEA activities on Tracking the Radiation Exposure of Patients

The IAEA launched its Smart Card/ SmartRadTrack project in 2009 to promote the tracking of radiation exposure history for individual patients undergoing radiological procedures. Significant progress has been achieved under this project, with a number of countries having implemented such tracking thus demonstrating how it can assist in the process of justification and optimization of patient exposures.

The last meeting in the series of technical and consultancy meeting on the subject was held by the IAEA on 28-30 April 2015. The meeting concluded that the experience from countries which have established regional or national system is encouraging in terms of use of both tracking of radiological procedures and dose. The consolidated information containing images with clinical information and dose has been found to be useful. Having individual patient’s dose tracking has been found to provide added value. The main conclusions from the meeting are available from https://rpop.iaea.org/RPOP/RPoP/Content/News/tm-on-tracking-radiation-exposure-of-patients.htm

4. IAEA support to training of health professionals and information exchange

The International BSS places great emphasis on education and training for all persons engaged in activities relevant to protection and safety. Different kind of resources is available from the dedicated website on Radiation Protection of Patients, https://rpop.iaea.org/. The website, available in English and Spanish, commonly known as RPOP website was launched in 2006 and has been a significant instrument of the IAEA to communicate information to health professionals, patients and public on benefits and risks of ionizing radiation in medical applications. It also provides training packages in three languages and posters in over 20 languages for free download and use, as well as links to all relevant IAEA publications, latest literature and latest news. The website RPOP has grown to be the top website of the world in the area of medical radiation protection, with over million visits and immense outreach in 213 countries. The website is kept updated and new information added. Social media, like Facebook and Twitter are also used to disseminate medical radiation protection information. IAEA maintains a voluntary reporting system SAFRAD (SAFety in RADiological procedures) where hospitals can report cases of patient exposure in fluoroscopically-guided diagnostic and interventional procedures above defined trigger levels. The primary objective of the system is educational in nature.

The training materials developed by the IAEA has been recognized to be a powerful tool to support the radiation protection education and training of healthcare professionals in the world. Nine training packages are available for free download at the Radiation Protection of Patients (https://rpop.iaea.org/) website, each targeting a specific field of medical use of ionizing radiation, and a particular group of professionals. A new training material on Radiation protection in dental radiology is expected to be available for free download later this year.

During the last decade, tens of training events have been organised and are being planned for radiologists, radiation technologists, medical physicists and other specialists using x-rays outside imaging departments, namely cardiologists, vascular surgeons, orthopaedic surgeons, gastroenterologists, etc. For more information, visit https://rpop.iaea.org/RPOP/RPoP/Content/AdditionalResources/Training/2_TrainingEvents/index.htm.

The Radiation Protection of Patient unit is launching in 2016 two new initiatives aimed to train more professionals in healthcare – e-learning and webinars. The first e-learning modules will be available soon on Radiation dose management in computed tomography (Fig. 3) and on Radiation safety in radiotherapy. Regular webinars on hot topics from the radiation protection in medical uses of ionizing radiation will start in February. The first webinar is scheduled for 4 February with the topic ‘Is cataract a real risk to those working in interventional suites?’. The information will be available from the Training page of the RPOP website.

5. Technical Cooperation (TC) activities for patient dose management.

The IAEA is assisting Member States in competence and skill development for justification and optimization of protection in medical exposures. The technical assistance to lower- and middle-income (LMI) countries is provided, by delivery of equipment, training, fellowships and scientific visits for knowledge exchange. A common approach has been established with scope for individual customisation by each country. The approach consists of classifying the work into detailed tasks, including dedicated tasks on dose management in CT and interventional radiology, with a special focus on paediatric patients. Over 80 LMI countries carry out work plans on patient dose assessments, whereas the IAEA provides assistance in performing the work, in the form of equipment support, training of staff, literature support and expert assistance. Significant results on patient dose management, demonstrating dose reduction of more than 30% while maintaining image quality, have been made available through the IAEA regional and national projects on patient protection. The results have been published in a number of scientific papers.

To support Members State efforts in establishing of DRLs and assessment of typical doses in individual facilities, templates for data collection and analysis and guidelines for use have been developed and distributed to counterparts in the Regional TC project for Europe RER9132. The dosimetry approaches are based on the International Code of Practice for Dosimetry in Diagnostic Radiology [8]. Using these templates patient dose assessment can be performed in general radiography, conventional fluoroscopy, fluoroscopy guided interventional procedures, mammography, computed tomography, nuclear medicine, including hybrid imaging (SPECT/CT and PET/CT). For CT, simple criteria for quick assessment of image quality for purposes of dose data collection are proposed and under testing in a number of project counterparts’ CT facilities. There is an ongoing European survey under the TC projects RER9132 and RER9135 on patient doses in hybrid imaging and in dental CBCT.

More information on the TC activities is available from the webpage  https://rpop.iaea.org/RPOP/RPoP/Content/InformationFor/MemberStates/index.htm