Position Paper Quality assurance in radiotherapy V.E. Kouloulias* European Organisation for Research and Treatment of Cancer (EORTC), Data Center, Avenue Mounier 83, B-1200, Brussels, Belgium Received 11 March 2002; received in revised form 14 June 2002; accepted 20 August 2002 Abstract In 1999, the European Organisation for Research and Treatment of Cancer (EORTC), being a European pioneer in the field of cancer research as well as in quality assurance (QA), launched an Emmanuel van der Schueren fellowship for QA in radiotherapy. In this paper, the work that has been done during the first E. van der Schueren fellowship is reported, focusing on four phase III EORTC clinical trials: 22921 for rectal cancer, 22961 and 22991 for prostate cancer and 22922 for breast cancer. A historical review of the QA programme of the EORTC Radiotherapy group during the past 20 years is included. # 2003 Elsevier Science Ltd. All rights reserved. Keywords: EORTC; Quality assurance; Radiotherapy 1. Historical review of the EORTC quality assurance programmes in radiation oncology 1.1. Institution structure and physical parameters The European Organisation for Research and Treat- ment of Cancer (EORTC) radiotherapy group was formed in 1975. The main goal of this group was to initiate and conduct clinical research in radiation oncology and its related fields. After a few years, a quality assurance (QA) programme was started to check the consistency of data collected from multiple partici- pating centres. The formal steps of the QA programme were established in 1982. Over the past 20 years, QA procedures have become a major part of the activities of the radiotherapy group. They are routinely used in every clinical trial and have resulted in a specific field of clinical research to develop methodologies that are gra- dually transferred to the entire radiotherapy community as well inside and outside clinical research. The first QA programme in the EORTC radiotherapy group was reported in 1986. The evaluation included three steps: a comparison of megavoltage units, tech- nical and staff environment, and data present in clinical and radiotherapy charts for each centre; radiation physics calibration of photon and electron beams; and radiation physics measurements on an anatomical phantom. The study included 17 institutions that were visited by a group of ‘‘experts’’ in radiotherapy and radiation physics from January 1982 to December 1984. Horiot and colleagues [1] reported the first part of the QA study in terms of assessment of medical staff and equip- ment. The second part was reported by Johansson and colleagues [2] regarding dosimetric intercomparisons. The dosimetric study in an anatomical phantom was reported also by Johansson and colleagues [3]. In 1993, Van Dam and colleagues [4] reported the results of mechanical checks of megavoltage units and simulators that were included in the on-site physics programme of the EORTC from 1987 onwards. Hans- son and colleagues [5] reported the mailed thermo- luminescence dosimeter (TLD) (in vivo measurements) dosimetry programme for machine output check and clinical application that started in 1986. Horiot and colleagues [6] in 1993 reported the detailed steps of the QA structure as well as the minimum requirements for QA in radiotherapy. In the framework of the experimental implementation of a European QA network for external radiotherapy, a report was published in 1995 on the use of mailed TL dosimeters to check the beam output and the beam quality of photon beams [7]. Inter-comparisons with the EORTC own mailed TL dosimetry have shown an 0959-8049/03/$ - see front matter # 2003 Elsevier Science Ltd. All rights reserved. PII: S0959-8049(02)00461-6 European Journal of Cancer 39 (2003) 415–422 www.ejconline.com * Tel.: +32-2-774-1-664; fax: +32-2-772-6-701. E-mail address: vko@eortc.be (V.E. Kouloulias).