Significance of treatment response when managing patients with primary central nervous system lymphoma

The precise role of radiation therapy in primary central nervous system lymphoma (PCNSL) remains controversial. We reviewed the records of all patients treated for PCNSL at our center between 2004 and 2015. A total of 103 patients treated with either chemotherapy alone (n = 30), radiotherapy alone (n = 36), or combined-modality treatment (n = 37) were analyzed. The median progression-free survival (PFS) and overall survival (OS) were 13.9 and 20.9 months, respectively. Of those who received chemotherapy, 52.2% achieved complete response/ unconfirmed complete response (CR/Cru) after induction; a trend for improved PFS was observed for those who received consolidation WBRT (NR vs. 30.1 months, p = .092) but not OS (NR vs. 31.6 months, p = .283). Patients who achieved a partial response with chemotherapy and proceeded with WBRT had a similar long-term survival to those who achieved CR/CRu with chemotherapy without WBRT (PFS 15.2 vs. 30.1 months, p = .888; OS 22.0 vs. 31.6 months, p = .340). Consolidation WBRT improved PFS, but not OS, and this must be balanced against possible risks of neurotoxicity.