CONSISTENCY IN QUALITY-CONTROL PROGRAMS FOR ELECTRON-ACCELERATORS IN RADIOTHERAPY CENTERS

Background and purpose: To gain insight into the current practice of q uality control (QC) of medical electron accelerators and to reduce pos sible variations in test frequencies and test procedures. Materials an d methods: An extensive questionnaire on QC procedures of medical elec tron accelerators was distributed and completed by all (21) radiothera py institutions in The Netherlands. The questions were related to safe ty systems, mechanical parameters, beam profiles, beam energy, absolut e dosimetry, wedge filters, the dose monitor system and radiation leak age. The data of the questionnaire were compared with recommendations given in national and international reports on QC of electron accelera tors. Results: Large variations in time spent on QC exist, especially for accelerators having dual energy photon beams and several electron beam energies. This diversity is mainly due to differences in philosop hy with regard to QC and the differences in resources and machine time available. Furthermore, large variations in test frequencies and test methodologies were observed. The staffing level involved in the QC me asurements was evaluated and compared with recent recommendations prov ided by EFOMP-ESTRO. Conclusions: From these recommendations and the r esults of the questionnaire, a set of minimum guidelines for a BC prog ramme could be formulated and implemented in all radiotherapy institut ions in The Netherlands. (C) 1998 Elsevier Science Ireland Ltd. All ri ghts reserved.