Quality assurance in radiotherapy: from radiation physics to patient- and trial-oriented control procedures.

The stepwise process of the EORTC Quality Assurance Programme in Radiotherapy is described in function of two main criteria: the targets of the quality control procedures implemented, in Radiation Physics and clinical research, by the EORTC Radiotherapy Group and the development of both trial- and patient-oriented quality systems. This exhaustive program, which started in 1982, is characterised by three main periods. The first one was fully dedicated to pioneer steps in Radiation Physics measurements, on-site audits and inventories of human resources, staff workload and department infrastructure in institutions participating to EORTC trials. During the second period, which started in the late 1980s, a series of quality systems were implemented to test the compliance of the investigators to follow protocol guidelines, through the use of standard and uniform control procedures like the dummy runs, in order to tackle systematic errors in the participating institutions. Finally, the third period, which took place in the 1990s, was essentially patient-oriented, thanks to large scale individual case reviews, to check the validity of data recording and reporting processes and trace random errors throughout the radiotherapy treatments. Most of the results collected during these two decades allowed the implementation of well codified quality control procedures which, nowadays, can be used outside the field of clinical research, by national societies or bodies willing to improve treatment standards on a large scale.