Efficacy of salvage radiotherapy for relapsed/refractory diffuse large B-cell lymphoma

BACKGROUND: Radiotherapy (RT) is a modality of salvage therapy in relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL), but its efficacy is currently not well defined. This paper reports a retrospective review of patients who received salvage RT for R/R DLBCL in our hospital. METHODS: We selected 32 patients who had relapsed and had progressive disease after chemotherapy or partial remission (PR) after chemotherapy. The patients had a median age of 47 years (range, 13–85 years) and were treated between January 1, 2009, and June 30, 2016. The histological type was DLBCL in all cases. Progression-free survival (PFS) and overall survival (OS) were estimated with the Kaplan-Meier method; predictors for adverse factors were evaluated using a Cox proportional hazards regression model. RESULTS: Median age-adjusted International Prognostic Index (IPI) score was 3 (range, 0–4), and 20 (62.5%) patients had large tumors. Patients were irradiated with a median dose of 42.7 Gy (range, 30–54 Gy): 4 (12.5%) by conventional RT, 2 (6.3%) by conformal 3D technique and 26 (81.3%) by intensity-modulated RT (IMRT). Most toxicities were mild (CTCAE grade 1 or 2), including neutropenia, diarrhea, dermatitis, mucositis and dysphagia. With a median follow-up of 25.4 months (range, 0.4–98.9 months) after irradiation, the 5-year PFS and OS were 61.8% and 83.2%, respectively. In multivariate analysis, adverse factors associated with PFS in our cohort were multiple lesions. CONCLUSIONS: Due to its low toxicity and ease of use, RT should remain a salvage therapy option for patients with R/R DLBCL.