The development of quality assurance programs for radiotherapy within the German Hodgkin study group (GHSG). Introduction, continuing work, and results of the radiotherapy reference panel

The German Hodgkin Study Group (GHSG), including more than 500 participating centers, established a central radiotherapy (RT) reference center to improve quality of treatment, starting with the first study generation in 1978. More than 11,000 patients with Hodgkin's lymphoma (HL) have been enrolled into these trials. Extensive continuing quality assurance programs (QAPs) during the study generations have been performed. The purpose of the present article is to summarize the experiences and results of the performed and ongoing QAPs. A panel of expert radiation oncologists (second study generation HD4-6, 1988-1994, and third study generation HD7-9, 1993-1998) retrospectively evaluated the adequacy of treatment fields, applied radiation doses, treatment time, and technical parameters. Furthermore, a detailed analysis of relapses in correlation with the performed RT was conducted. For the fourth study generation (HD10-12, 1998-2002), the RT reference center changed from Munich to Cologne. New RT QAPs were initiated according to the demands of the new trials and former programs were enhanced: (1) central prospective radiation oncologic review of cross-sectional imaging (HD10, HD11) to create the individual radiation treatment plan; (2) retrospective analysis of the adequacy of the performed involved-field (IF) RT (HD10, HD11); (3) the multidisciplinary HD12 panel (radiation oncologists, medical oncologists, diagnostic radiologists); (4) initiation and integration of a teleradiotherapy network into the GHSG trials. (orig.)