MEDIRAD research has addressed the following three key aspects for the radiation protection of patients and of medical workers.
This recommendation addresses the growing field of molecular radiotherapy (MRT) in nuclear medicine, focusing on improved radiation protection of patients through personalised treatment. The individual patient determination of pharmacokinetics and radiation dosimetry of established and innovative radiopharmaceuticals, greatly depends on the data provided by quantitative nuclear medicine imaging through gamma cameras, for which standardised protocols and performance are currently lacking. Characterisation of gamma camera performance for high activity quantitative imaging enables personalised treatment planning in MRT. It also enables standardised collation of quantitative image data and absorbed dose calculations to facilitate multi-national, multi-centre, clinical studies and to allow accurate absorbed dose estimations.
To achieve this, a number of challenges need to be addressed:
Variability in methodologies to set up imaging systems for quantitative imaging and obtain calibration factors such as system volume sensitivity, partial volume recovery factors, and dead-time factors.
Lack of guidance documents for quantitative imaging for different radionuclides.
Lack of in-built capability and/or significant associated costs for additional software packages to allow for quantitative imaging.
Lack of standardisation of imaging systems of different manufacturers.
To allow for quantitative imaging of radiopharmaceuticals and absorbed dose calculations, standardised protocols must be established, and this MEDIRAD recommendation proposes a way toward this goal.
MEDIRAD research has highlighted how a closer cooperation between medical professionals can benefit the patient’s radiation protection. Patients undergoing diagnostic and therapeutic procedures involving ionising radiation should receive care and follow-up from a multidisciplinary group of relevant specialists; especially in the case of adverse tissue reactions due to the radiation treatment. The multidisciplinary consortium of experts brought together by the MEDIRAD project, in radiology, radiotherapy and nuclear medicine, as well as in nuclear and radiation protection research has identified several avenues to ensure adequate and improved radiation protection of patients and medical personnel.
MEDIRAD research has focused on one of the exposure situations that accounts for a significant part of the collective dose received by medical professionals in European hospitals: the conduct of fluoroscopically-guided procedures in interventional radiology. Staff performing these procedures can be exposed to low doses of ionising radiations on a daily basis, eventually resulting in high doses throughout a complete career. The radiation field to which staff are exposed is highly heterogeneous, resulting in some body parts being more exposed than others. In general, workers wear at least a lead apron that partially protects most organs in the trunk, but other parts of the body can be unprotected, such as the skin of the hand and fingers which are usually close to the X-ray beam during most procedures.
Additionally, there has been increasing concern in recent years regarding exposure of the eye lens and brain, highlighting the need for optimising staff protection. Innovative protection devices have appeared on the market but the current European regulation does not provide practical criteria to support medical physicists and radiation protection experts in the selection of these devices. The EURATOM 2013 European directive simply states the need for providing, testing and checking “appropriate personal protective equipment”, while the regulation on personal protective equipment underlines the selection of “the type and equivalent thickness of the constituent material(s) suitable for the foreseeable conditions of use”, “without leading to an increase in exposure time as a result of the impedance of user gestures, posture or movement”. Further, the general requirements in the international standards on, among others, the properties of the materials and the equipment themselves, are not sufficient to ensure effectiveness in clinical practice.
As a result, the use of such protective equipment is not as common as it should ideally be. MEDIRAD research identified that increased independent testing of such equipment, with reference to typical and realistic conditions of use, would be an effective way to promote better radiation protection practice for the medical workers concerned.