Long-term efficacy and curative potential of radiotherapy in early and intermediate stages of Hodgkin's disease - experiences of the German Hodgkin Study Group (GHSG)

Between 1984 and 2001 more than 5000 patients were enrolled in the multicentric randomized trials of the GHSG and are evaluable for response, survival, recurrences, and toxicities. An extensive radiotherapy (RT) quality assurance program has been practiced during the study generations to improve nationwide patients sufficient therapy and adequate RT. Since 1998 involved field radiotherapy (IF-RT) is prospectively planned by the RT reference center in Cologne. The 1st protocol generation, HD0 - HD3 proved the efficacy of standard extended field (EF)-RT of 40 Gy in early stages and the combined modality treatment (CMT) of chemotherapy (CT) with COPP and COPP/ABVD with additional RT. In the 2nd generation (HD4 trial) including stage I + II without risk factors, there was no difference in FFTF comparing EF-RT of 40 Gy with EF-RT of 30 Gy plus 10 Gy to involved areas. Though the failure rate of 25% was quite high, long-term survival was more than 90% due to excellent salvage options. The 3rd generation (HD7) examined the efficacy of initial short term CT with 2 x ABVD before EF-RT of 30 Gy and IF-RT of 40 Gy to RT alone. Final results showed significant reduction of failures after CMT. The ongoing HD10 trial for early stages compares 2 vs. 4 cycles of ABVD before IF-RT of 30 Gy vs. 20 Gy. For intermediate stages, HD5 showed no benefit for COPP/ABV/IMEP vs. standard COPP/ABVD. The following HD8 trial proved the same efficiency of EF-RT vs. IF-RT after 2 x COPP/ABVD. The ongoing HD11 trial tests different CT (ABVD vs. BEACOPP) with 2 vs. 4 cycles and the additional effect of 30 Gy vs. 20 Gy IF-RT. There was a continuous shift from EF-RT to only IF-RT for definitive treatment of early and intermediate stages of Hodgkin's disease after CT during the last 17 years. Based on these experiences CMT with ABVD and IF-RT is recommended for early and intermediate stages