Invited Lecture 2.3

Abstract

There are ongoing efforts to revisit and potentially revise the current system of radiation protection. While the IAEA view calls for the overall stability of the system, which would allow for adoption and implementation of the currently available recommendations, requirements and associated guidance and supporting materials, the IAEA also supports efforts in clarification. There are some emerging issues in medical exposure that may have an impact on the radiation protection system. The first of these is the issue of recurrent medical radiological imaging, also called multiple or frequent imaging. Many articles have been published over the last years on the large group of patients who undergo multiple imaging, where a conservative estimate is that around a million patients globally who undergo CT exams cumulate more than 100 mSv in a limited time. The second is the issue of scenarios in the rapidly growing modality of fluoroscopy-guided interventional procedures in which the radiation dose given to a patient may reach or exceed a threshold for tissue reactions, but where the radiation dose is neither unexpected nor preventable but unavoidable, considering all benefits and risks as well as benefits and risks of alternative procedures. The third is the issue of second primary cancers following radiotherapy. With longer life expectancies for larger groups of patients following radiotherapy, the risk of induction of a second primary cancer from the ionizing radiation in the treatment of the first primary cancer becomes increasingly important to consider. Presently, optimization in radiotherapy is mainly concerned with unwanted effects in organs at risk surrounding the target volume. Looking forward, stochastic effects in volumes outside the target may also need to be considered more. The IAEA has done work in all these three areas, which will be discussed.