Description: Publication date: Available online 6 July 2018 Source: Radiotherapy and Oncology Author(s): Everett J. Moding, Ranjana Advani, Saul A. Rosenberg, Richard T. Hoppe Background and purpose The role of irradiation to non-bulky and bulky sites of disease in advanced stage Hodgkin lymphoma is controversial. We aimed to review the long-term outcomes of patients treated with combined modality therapy to clarify the role of consolidative radiotherapy. Materials and methods Patients with stage III or IV Hodgkin lymphoma treated with Stanford V chemotherapy and consolidative radiotherapy to initial sites of disease ≥5 cm were analyzed retrospectively to determine patient outcomes, patterns of failure, and factors associated with treatment failure. Results A total of 170 patients were analyzed. Overall survival was 91.2%, freedom from progression was 80.6%, and progression-free survival was 78.9% at 10 years. 5 patients (2.9%) had refractory disease and 27 patients (15.9%) relapsed after treatment. Only an International Prognostic Score (IPS) greater than 2 predicted disease progression. 19 out of 27 relapses occurred exclusively outside of the radiation treatment field, and 17 out of 27 relapses occurred exclusively at original sites of disease. However, only 11 of 170 patients (6.5%) relapsed exclusively at original, non-bulky sites of disease not treated with radiation therapy. The cumulative incidence of local failure at 10 years was 4.6% for unirradiated sites and 2.6% for irradiated sites. Conclusion Patients with advanced stage Hodgkin lymphoma treated with combined modality therapy including consolidative radiotherapy to bulky disease sites had excellent long-term outcomes. Given the low frequency of isolated failures at initial sites, our results suggest that selective radiation therapy to sites at high risk of relapse may be feasible.