Specificities of clinical research in radiotherapy.

The aim of this review is to present the specificities of clinical research in radiation oncology. Objectives are similar to all research in oncology: to improve the efficacy and to decrease toxic effects. Phase III trials remain the main methodology to demonstrate an improvement in efficiency, but phase I-II and registers are also important tools to validate an improvement in the therapeutic index with new technologies. In this article we discuss the special features of end-points, selection of population, and design for radiation oncology clinical trials. Quality control of delivered treatments is an important component of these protocols. Financial issues are also discussed, in the particular context of France.