The role of adjuvant radiation therapy for stages III and IV Hodgkin's disease

Abstract

The treatment for advanced stage Hodgkin's disease was revolutionized approximately 30 years ago with the introduction of combination chemotherapy. This approach has resulted in the cure of approximately 50% of patients with advanced disease. In an effort to improve these results, consolidation radiotherapy (RT) was introduced approximately 25 years ago. The rationale for adjuvant RT comes from several observations: significant numbers of patients relapse following combination chemotherapy alone, these relapses occur predominantly at initially involved sites, and successful salvage following relapse can be quite difficult to achieve. Data from numerous phase II trials have demonstrated that adjuvant RT significantly reduces the relapse rate compared with what is seen following chemotherapy alone and appears to increase survival as well. Phase III trials have confirmed the reduction in relapse but, as yet, have failed to demonstrate survival benefits. Because definitive phase III trials are lacking, the use of consolidation radiotherapy has gained only partial acceptance and remains controlversial. There have been numerous methodological difficulties with the execution of the reported phase III trials, most notably the failure of a substantial portion of patients randomly allocated to the radiotherapy group to actually receive radiation. This review presents updated results of studies using chemotherapy alone including patterns of failure analyses, summarizes the available literature pertaining to both retrospective and prospective trials of combined modality therapy, discusses toxicity issues, and attempts to provide guidelines regarding patient selection, sequencing of chemotherapy and radiotherapy, and radiation dose and field size. It is our conclusion that the available evidence supports the routine use of combined modality therapy for patients with advanced stage Hodgkin's disease.