ML-5 THE TRANSITION OF THE TREATMENT OF 60 PCNSL CASES AT OUR INSTITUTION AND CLINICAL CONSIDERATIONS

The efficacy of RMPV-A (rituximab, methotrexate, procarbazine, vincristine, and cytarabine) and whole brain irradiation for primary central nervous system lymphoma (PCNSL) have recently been reported. Our institution also introduced RMPV therapy in 2020 after an era of conventional HD-MTX to cytarabine and rituximab combination. In this report, we analyzed 60 PCNSL cases treated from 2013 to 2021.There were 32 female patients (53%) with a median age of 70 years (30-87). Five patients (8%) received radiotherapy alone as initial treatment, 30 (50%) received HD-MTX (including radiation), 17 (28%) received HD-MTX plus rituximab or cytarabine, and 9 (13%) received RMPV therapy. The response rate (CR, CRu, PR) in the HD-MTX group was 88%, and the complete response rate (CR, CRu) was 51%. In contrast, the RMPV arm had a response rate of 100% and a complete response rate of 6 patients (66.7%). 7 patients (14%) in the HD-MTX arm and 2 patients (22%) in the RMPV arm were unable to continue treatment due to adverse events. The treatment of PCNSL has undergone significant changes in recent years, with the availability of RMPV-A, thiotepa, and tirabrutinib, and it is now possible to construct treatment that avoids leukoencephalopathy caused by radiation therapy as much as possible, which had been a major problem of conventional therapy. However, because of the use of strong drugs, caution must be exercised when treating patients in poor general conditions, especially the elderly. However, the present analysis indicates that many elderly patients can be successfully treated with careful observation. In the future, it is essential to accumulate cases treated with RMPV therapy and tilabrutinib and conduct further data analysis to establish a new generation of treatment for PCNSL.