Radiation Oncology (Jun 2012)
Radiotherapy dose–response analysis for diffuse large B-cell lymphoma with a complete response to chemotherapy
Abstract
Abstract Objective To examine the efficacy of different radiation doses after achievement of a complete response to chemotherapy in diffuse large B-cell lymphoma (DLBCL). Methods Patients with stage I-IV DLBCL treated from 1995–2009 at Duke Cancer Institute who achieved a complete response to chemotherapy were reviewed. In-field control, event-free survival, and overall survival were calculated using the Kaplan-Meier method. Dose response was evaluated by grouping treated sites by delivered radiation dose. Results 105 patients were treated with RT to 214 disease sites. Chemotherapy (median 6 cycles) was R-CHOP (65%), CHOP (26%), R-CNOP (2%), or other (7%). Post-chemotherapy imaging was PET/CT (88%), gallium with CT (1%), or CT only (11%). The median RT dose was 30 Gy (range, 12–40 Gy). The median radiation dose was higher for patients with stage I-II disease compared with patients with stage III-IV disease (30 versus 24.5 Gy, p Conclusion In-field control was excellent with a combined modality approach when a complete response was achieved after chemotherapy without a clear radiation dose response.