ML-12 HIGH-DOSE CHEMOTHERAPY AND AUTOLOGOUS STEM CELL TRANSPLANTATION (HDC-ASCT) FOR THE PATIENTS WITH PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA (PCNSL)

High-dose chemotherapy and autologous stem-cell transplantation (HDC-ASCT) for the patient with primary central nervous system lymphoma (PCNSL) has been used as treatment at relapse or as consolidation therapy. We report on the efficacy, safety, and future issues of HDC-ASCT. Twelve patients with PCNSL (10 males and 2 females) underwent HDC-ASCT, ranging in age from 45 to 66 years (median 58 years) and KPS from 70 to 100 (median 90) at the time of HDC-ASCT. HDC-ASCT was performed at the time of consolidation therapy (without radiation) in 7 patients, at first recurrence in 4 (including 1 without radiation), and at second recurrence in 1. Department of Neurosurgery and Neuro-Oncology (NSNO) was in charge from diagnosis to just before transplantation, Department of Hematopoietic Stem Cell Transplantation (HSCT) was in charge of HDC-ASCT, and Department of NSNO was in charge after discharge again. The conditioning regimen consisted of busulfan 3.2mg/kg/day for 4 days and thiotepa 5mg/kg/day for the 2 following days, followed by ASCT. The observation period after HDC-ASCT ranged from 2.8 to 43 months (median 16.1 months), and the hospitalization period for HDC-ASCT ranged from 26 to 38 days (median 33 days), with no serious complications. All patients have returned to society and there have been no deaths to date, but two patients (after 4.7 months and 10.9 months) had relapses, of which two were treated with tirabrutinib, and one was subsequently treated palliatively. HDC-ASCT in PCNSL is an important option to improve outcomes. Since the main focus of this treatment is Department of HSCT, it is important to have sufficient cooperation and communication among the departments from the time of tumor diagnosis until after the patient is discharged from transplantation, and it is essential to be fully aware of each role.