Repeated courses of low-dose 2 × 2 Gy radiation therapy in patients with indolent B-cell non-Hodgkin lymphomas

Purpose: In patients with indolent B-cell non-Hodgkin's lymphoma (B-NHL), one course of low-dose radiotherapy (LD-RT) 2 × 2 Gy is emerging as new option of therapy in palliative setting. Efficacy of LD-RT when repeated remains to be determinate. This study aims to assess the efficacy of repeated LD-RT given in patients with indolent B-NHL. Materials and Methods: All consecutive adult patients who received two or more courses of LD-RT 2 × 2 Gy for indolent B-NHL at Gustave Roussy institution, during the period 1990-2015 were retrospectively investigated. Results: Thirty-three patients received two or more courses of LD-RT for indolent B-NHL during the study period. The median age was 57 (range 37-80) years, histological types were distributed among follicular lymphoma (n = 24 pts; 73%), marginal-zone lymphoma (n = 6 pts; 18%), and primary cutaneous follicle center lymphoma (n = 3 pts; 9%). The median number of low-dose radiation therapy courses given per patients was 2 (range 2-6). The overall response rates following the first and the second course of LD-RT were 96% and 88%, respectively (P =.31). The 1- and 2-years local control rates following the first courses of LD-RT were 94% (CI 95: 86-100) and 94% (CI 95: 86-98); and were 91% (CI 95: 82-100) and 88% (CI 95: 77-100) following the second course of LD-RT (P =.39). Conclusion: The repeated courses of LD-RT offered similar efficacy compare with the first course in patients with indolent B-NHL. LD-RT repeated is a simple, easy to give, and non-toxic asset that could be investigated as treatment option in patients with indolent B-NHL.