Partial-brain radiotherapy for primary central nervous system lymphoma: Multi-institutional experience

Whole-brain radiotherapy (wbrt) has been an important component of treatment for primary central nervous system lymphoma (pcnsl),but delayed neurotoxicity has been a matter of concern. we have employed partial-brain radiotherapy (pbrt) with wide margins for pcnsl patients with a single lesion or a few lesions. in this study,we evaluated the treatment outcome in pcnsl patients undergoing pbrt. between 2003 and 2014,24 patients were treated with pbrt; 16 received high-dose-methotrexate (mtx) -containing chemotherapy before pbrt. conventional fractionation with a median dose of 54 gy was used. for reference,15 patients undergoing mtx-based chemotherapy and wbrt were also analyzed. the 3-year overall survival rate was 60% for all 24 patients undergoing pbrt and 68% for the 16 patients undergoing mtx-based chemotherapy plus pbrt. the 3-year progression-free survival rate was 41% for all 24 patients undergoing pbrt and 36% for the 16 patients undergoing mtx-based chemotherapy. the in-field recurrence rate was 26% and the out-of-field recurrence rate was 15% at 3 years for all 24 patients undergoing pbrt. the rates for in-field recurrence and the out-of-field recurrence were 27% and 21%,respectively,for the 16 patients undergoing mtx-based chemotherapy. cns-recurrence rates were similar in patients undergoing mtx-based chemotherapy and pbrt to the rates in those undergoing mtx-based chemotherapy and wbrt. neurocognitive dysfunction developed in 3 of the 16 patients undergoing mtx + pbrt and in 4 of 15 patients undergoing mtx + wbrt (p = 0.68). pbrt seems to be a feasible treatment option for solitary pcnsl. further investigations are warranted to evaluate the advantages of pbrt over wbrt. © 2015 the author 2015. published by oxford university press on behalf of the japan radiation research society and japanese society for radiation oncology.