Hodgkin's disease--the role of radiation therapy in advanced disease.

The success of radiation therapy (XRT) in the management of early-stage Hodgkin's disease (HD) has led to its use in a variety of programs for the management of advanced disease. This article includes discussion of these roles of radiation in advanced disease: 1) use of XRT as an adjuvant after chemotherapy; 2) use of XRT to convert patients who are 'partial responders' (PRs) after chemotherapy to 'complete responders' (CRs); 3) use of XRT as an integrated component of combined modality therapy; 4) use of XRT as a 'salvage' treatment after failure of primary chemotherapy; and 5) incorporation of XRT into programs of high-dose therapy with autologous stem cell (or marrow) rescue. 1) Randomized trials of adjuvant XRT after completion of chemotherapy in advanced disease have been conducted by the Southwest Oncology Group (SWOG), German HD Study Group, and the European Organization for the Research and Treatment of Cancer/Group Pierre Marie Curie (EORTC/ GPMC). The SWOG study shows improvements in disease-free survival, but not overall survival with the addition of XRT. The German Study Group trial was negative, but the number of patients reported in the abstract of the trial was too small to be conclusive. The EORTC/GPMC study has not been reported. 2) Both the SWOG and EORTC/GPMC trials treated "PRs' with XRT. Results in both show conversion to CR in > 80% of patients. Conversion to CR was most likely for patients with just minimal residual disease after chemotherapy. 3) Planned XRT in advanced disease (especially bulky sites) may permit reduction in chemotherapy doses (e.g., the Stanford V chemotherapy program) and maintain excellent outcome (freedom-from-progression > 80%). Reduction in total doses of chemotherapy as well as dose and extent of radiation should limit potential long-term toxicity. 4) Very selected patients with asymptomatic limited nodal relapse may be "salvaged' with XRT, but published reports include only a small number of patients and this should not be considered a standard approach. 5) XRT may be used as total body, total lymphoid, or local field in high-dose therapy programs. Since HD at relapse is still often a local-regional problem, local field irradiation is probably the most rational approach to use in this setting. Recent Stanford data show an improvement in outcome with the inclusion of local field treatment in these patients.