Consolidative radiation therapy for stage III hodgkin lymphoma in patients who achieve complete response after ABVD chemotherapy

OBJECTIVES: To examine the role of consolidation radiation therapy (RT) for patients with stage III Hodgkin lymphoma. METHODS: We retrospectively reviewed 118 patients with stage III Hodgkin lymphoma who were diagnosed and treated at the University of Texas M.D. Anderson Cancer Center from 1993 through 2006. We evaluated the influence of site and size of initial involvement and use of consolidative RT on survival and patterns of failure after complete response (CR) to ABVD chemotherapy (doxorubicin, bleomycin, vinblastine, and dacarbazine). RESULTS: After chemotherapy, 104 patients (88%) achieved CR; median follow-up time was 68 months (range, 8 to 190). Seventy-one patients (68%) received ≥6 cycles of ABVD, and 40 patients (38.5%) received consolidative RT. Comparing patients who received RT with those who did not, the 5-year, 10-year, and 15-year overall survival (OS) rates were 98%, 80%, and 80% versus 91%, 72%, and 29%, respectively (P=0.08). Disease-free survival (DFS) rates were 94%, 81%, 65% versus 78%, 45%, and 15%, respectively (P=0.04). On multivariate analysis, the presence of initial mediastinal involvement (P=0.001) and bulky head and neck disease (P=0.001) was associated with worse DFS; mediastinal RT was associated with improved DFS (P=0.003) and OS (P=0.029). Use of ≥6 cycles of ABVD was associated with improved OS (P=0.001). The pattern of failure analysis showed that most failures (23 of 28) occurred above the diaphragm. CONCLUSIONS: Consolidative RT after CR may benefit patients with initial disease above the diaphragm, whereas below-the-diaphragm disease seems to be well managed by chemotherapy alone.