Favorable Outcome After Adjuvant Involved-Field Radiotherapy After Autologous Hematopoietic Stem-Cell Transplantation In Patients With High-Risk Relapsed/Refractory Lymphoma: A Single-Center Experience

Involved-field radiotherapy (IFRT) has been used in the peritransplantation period to minimize the risk of disease recurrence after autologous hematopoietic stem-cell transplantation in patients with bulky or residual lymphoma after salvage chemotherapy. However, the optimal timing of radiotherapy still remains under investigation. We provided IFRT early after transplantation in high-risk patients and demonstrated high survival rates with extremely low toxicity.Background: Patients with refractory or relapsed lymphoma diagnosed with bulky disease at relapse or with residual disease after salvage treatment are considered to have a dismal outcome, even after autologous hematopoietic stemcell transplantation, as a result of disease recurrence. To minimize the risk of relapse after receipt of a transplant, involved-field radiotherapy (IFRT) to sites of either bulky or localized residual disease has been utilized; however, the ideal timing for irradiation remains controversial. The aim of this study was to assess the safety and efficacy of IFRT in the early period after transplantation. Patients and Methods: We retrospectively evaluated the outcome of 24 autografted patients with relapsed/refractory lymphoma who presented with bulky disease at relapse or who had a persistent localized residual mass after salvage treatment and consolidated with IFRT within 4 months after autografting. Results: No significant toxicity was noticed during the early postradiotherapy period, while graft function was not impaired. After a median follow-up of 3 years for survivors, 21 patients were alive, 19 of whom were event free, while 2 patients died of disease recurrence and 1 died of treatment-related myelodysplastic syndrome. The 3-year overall, lymphoma relapse-free, and event-free survival rates were 86%, 86%, and 82%, respectively. Conclusion: Taking into consideration the poor-risk features of the study cohort, IFRT provided early after autologous hematopoietic stem-cell transplantation showed a safe and well-tolerated toxicity profile and demonstrated long-term effective tumor control, as reflected in the promising survival rates. (C) 2020 Elsevier Inc. All rights reserved.