ICRP Workshop for Task Group 108 - Optimisation of Radiological Protection in Digital Radiology Techniques for Medical Imaging
Stewart Whitley, Director of Professional represented, as a panellist, the ISRRT at the ICRP TC108 Workshop Part 1 26th October 2022 by giving a short presentation which was a synopsis of the ISRRT’s response to the ICRP’s consultation document on ‘Optimisation of Radiological Protection in Digital Radiology Techniques for Medical Imaging’.
ICRP Workshop for Task Group 108 - Optimisation of Radiological Protection in Digital Radiology Techniques for Medical Imaging
The ICRP has just completed a consultation on ‘Optimisation of Radiological Protection in Digital Radiology Techniques for Medical Imaging’ which can be found at https://www.icrp.org/docs/TG108%20Pt%201%20Optimisation%20in%20Digital%2...
Individuals and professional organisation were given the opportunity to comment on the proposed document which closed for comments 28th October 2022.
The ISRRT submitted a number of comments and suggested changes to this important document which addresses a range of issues associated with CT and digital radiography imaging.
The main points in the document are explained as:
Optimisation is a key principle of radiation protection. Medical exposures are the most significant contributor to the exposure of the population world-wide from artificial sources of radiation, so optimisation is especially important in this field.
Optimisation of radiological imaging requires that dose levels are reduced as much as possible, while providing images of sufficient quality and appropriate coverage with the information required for the diagnostic purposes.
The emphasis on image quality has become crucial in digital radiology with more versatile image acquisition, post-processing, and presentation options. This requires a more rigorously defined optimisation process and awareness of underlying technical factors that are not always obvious.
The clinical risk from an examination for which the dose has been reduced to the point at which changes in diseased tissue cannot be visualised because the level of image quality is insufficient are likely to be high, compared to any additional risk from a higher radiation exposure. However, cumulative radiation doses from the ever-increasing use of radiology may result in health consequences that, although not immediately apparent, could manifest at a later point in time. Thus, it is a question of balance between different types of risks (potential long-term effects from dose and more immediate clinical consequences).
Uncertainties, which are specific to the procedure, make achieving this balance a challenging task for both technical and professional aspects.
In order to ensure that optimisation is carried out, a facility must have sufficient imaging equipment, and enough staff who have been adequately trained to use it. The optimisation process starts with specification of the equipment required to fulfil the clinical need, and continues through its purchase, installation, acceptance, and commissioning. It includes the maintenance and the quality assurance programme which continue throughout the life cycle of the equipment.
Optimisation requires the input of knowledge and skills on many different aspects of how radiological images are formed and so requires contributions from different healthcare professionals working together as a team. The radiologist or other clinician can judge whether the image quality is sufficient for the diagnostic purpose, the radiographer should know the practical operation and limitations of the equipment, and the medical physicist should understand the physical principles behind image formation and can perform and interpret measurements of dose and image quality.
In order to achieve optimisation, the three specialities, together with other healthcare professionals who will sometimes be involved, must have mutual respect for their individual skills and work together as a cohesive group (i.e. professionalism). Unfortunately, the levels of knowledge and skills in many countries are often inadequate to achieve good optimisation on more complex digital radiology systems at the time of preparation of this report. Increasing technical and computational complexity in radiology equipment and applications underlines the importance of multi-professional collaboration and dependency on the combined knowledge of different professionals. Dedicated time must be made available for the professionals to work together to meet emerging challenges in optimisation as applications of new equipment are developed.
Digital imaging provides the potential for images to be obtained with lower exposures than possible using film screen combinations, enabling levels to be adapted to the diagnostic requirements of particular examinations. New techniques are continuously becoming available that can improve image quality and potentially enable diagnostic images.
The document is very extensive,101 pages long, and full of helpful information as to how radiologists, medical physicists and radiographers/radiological technologists can work together to ensure optimum image quality bearing in mind the risk of radiation to the patient.
Stewart served as a panellist on day 1 of the workshop and presented the ISRRT’s feedback following consultation with its members. This session included feedback from other international organiations including the International Society of radiologists (ISR) and the International Organisation for Medical Physics (IOMP).
Stewart also represented ISRRT on Day 2 of the workshop which addressed ‘Putting optimisation into practice’
A full report will be available in the ISRRT December’s News and Views newsletter.
A.S. Whitley. ISRRT Director of Professional Practice – 2.11.2022