Long-Term Outcome and Prognostic Factors in Early-Stage Nodal Low-Grade Non-Hodgkin's Lymphomas Treated with Radiation Therapy

Purpose: Retrospective analysis of therapy results in patients with stage I-II and limited stage III nodal low-grade non-Hodgkin's lymphoma (NHL). Patients and Methods: The present retrospective study covers 65 patients treated between 1988 and 2006 at the Department of Radiation Oncology, University of Cologne, Germany. 50 patients were treated with radiotherapy alone (EF [extended field]: n = 35, IF/REG [involved field/regional field]: n = 9, TNI/TLI [total nodal/total lymphatic]: n = 6), 15 patients additionally received chemotherapy. Median age was 58 years. 58 patients presented with centroblastic-centrocytic or follicular lymphomas, seven patients had centrocytic lymphomas. Apart from overall and relapse-free survival, relapse patterns were examined and the impacts of patient characteristics and therapy modalities were analyzed. Results: After a median follow-up of 9.1 years, overall 5-year and 10-year survival was 86% and 55%, relapse-free survival was 55% and 37%, respectively. Relapses occurred in 28 patients during the observation period. Overall survival was favorably influenced by low patient age (p = 0.037), centroblastic-centrocytic/follicular histology (p = 0.006), and early disease stage (p = 0.045). Favorable prognostic factors for relapse-free survival were low patient age (p = 0.035) and centroblastic-centrocytic/follicular histology (p = 0.001). Conclusion: Radiotherapy of early-stage low-grade NHL is a curative therapy option, particularly in younger patients and patients with follicular histology. Relapse analysis confirmed the benefits of total nodal or total lymphatic irradiation, although the small number of patients needs to be considered.