[The Efficacy and Safety of Modified Thiotepa-Based Conditioning Followed by Autologous Stem Cell Transplantation in...

To explore and evaluate the efficacy and safety of a modified thiotepa-based conditioning regimen combined with autologous hematopoietic stem cell transplantation (ASCT) for the treatment of primary central nervous system lymphoma (PCNSL).

In a retrospective, single center, single arm study, we collected data of 28 patients with PCNSL who underwent high-dose chemotherapy followed by autologous stem cell transplantation (HDC-ASCT) at our center from March 2021 to December 2024. The clinical characteristics of the patients, the conditioning regimen details, treatment-related toxicities and adverse reactions, post-transplant disease remission status, and survival outcomes were analyzed.

A total of 28 patients were included. Among them, 19 patients received ASCT as first-line consolidation therapy in complete response (CR) or partial response (PR) status, and 9 patients with relapsed/refractory disease underwent salvage ASCT. The median time to neutrophil engraftment was 9 days (range: 5-11 days), and the median time to platelet engraftment was 10 days (range: 6-13 days). All patients achieved CR at the initial efficacy evaluation post-ASCT. The main complications during the transplantation period were febrile neutropenia (26 cases) and grade 3 diarrhea (9 cases). No transplantation-related mortality occurred. Post-ASCT, 19 patients received maintenance therapy, which was demonstrated to be safe and effective. Three patients relapse, and one patient died. The median progression-free survival (PFS) and overall survival (OS) of patients were not reached. The estimated 1-year and 2-year cumulative PFS rates were 88.4% and 66.3%, respectively, while the 1-year and 2-year OS rates were both 94.1%.

The modified thiotepa-based conditioning regimen combined with ASCT is safe and effective for the treatment of PCNSL.