Salvage therapy and late neurotoxicity in patients with recurrent primary CNS lymphoma treated with a modified ProMACE-MOPP hybrid regimen

We report the efficacy of salvage therapy with a modified ProMACE-MOPP combined with radiation in patients with primary central nervous system lymphoma (PCNSL). Thirty-two immunocompetent patients were treated with a regimen of pirarubicin, cyclophosphamide, etoposide, vincristin, and methotrexate (MTX: 500 mg/m²) administered in 21-day cycles. Patients received 20 Gy of whole-brain radiotherapy after three cycles of chemotherapy. A single cycle of chemotherapy was repeated every four months for two years. Nine patients with CNS relapse were retreated with additional cycles of the ProMACE-MOPP hybrid regimen with a 90% objective response rate. Median complete response (CR) duration was 13.2 months and median survival time (MST) for the nine patients treated after initial relapse was 30 months. One of 17 patients (5.8%) who had less than 20 Gy of whole brain irradiation developed dementia. In contrast, six of seven (85.7%) patients who had more than 30 Gy of whole brain radiotherapy became demented. Maintaining a moderate dose of MTX, while adding chemotherapeutic agents and 20 Gy of whole brain radiation therapy, improved disease control and overall survival and lowered the incidence of delayed neurologic toxicity in patients with PCNSL. Additional treatment with a ProMACE-MOPP hybrid regimen is still effective for relapsed disease.