Deviations in radiotherapy administration
Accuracy and precision play an important role in radiotherapy. Knowledge of the uncertainties in the delivery of an RT treatment, both in dosimetry and geometry, is important because if a misadministration is significant it results in an under- or overdose resulting in a potential failure to control the disease or an increased risk on normal tissue damage. There is good evidence that differences of 10% in dose are detectable in a number of clinical situations. Modern treatment techniques such as 3D conformal RT and IMRT, having steep dose gradients, require in addition very accurate patient positioning.
In attempting to avoid accidents in radiotherapy, it is very important to study the lessons that can be learned from previous radiotherapy accidents and to ensure that preventive actions are applied in a clinical setting. From the analysis of a number of recent accidents (and incidents) occurring in radiotherapy institutions after the introduction of new technology, it became evident that a considerable number of these accidents were due to insufficient training of the responsible person. Education and training are therefore critical issues for the safe implementation of new technology and should be well thought-out before new tools are installed.
Introduction to References
Deviations in RT administration have been discussed at many places including the IAEA Handbook, the ROSIS website, and the BIIJ article of Olmberg. A number of accidents in RT have been thoroughly investigated by the IAEA, and the lessons learned from these accidents disseminated. The ICRP has also summarised causes and contributory factors for RT accidents. More recent accidents have been summarised in a new ICRP report, and those that occurred in France by Derreumaux et al. Deviations in IMRT delivery have been presented in the paper by Ibbott et. al.