Role of Salvage Radiation Treatment of Relapses in Relapsed/Refractory Diffuse Large B Cell Lymphoma Post Autologous Stem Cell Transplant
Menée à l'aide de données portant sur 165 patients atteints d'un lymphome diffus à grandes cellules B récidivant ou réfractaire et ayant reçu une greffe autologue de cellules souches hématopoiétiques sur la période 2004-2016 (durée médiane de suivi : 48,9 mois), cette étude analyse, du point de vue du taux de réponse objective, l'efficacité d'une radiothérapie de sauvetage
Purpose: Approximately 50% of patients with relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL) will relapse post autologous stem cell transplant (ASCT) and the role of salvage therapy is not well defined. We examined radiation therapy (RT) as salvage treatment in this patient population. Materials and Methods: A retrospective review of patients with DLBCL who had an ASCT during 2004-2016 and subsequently relapsed was performed. Clinical and pathologic characteristics were collected including detailed information regarding post-ASCT treatment. Response rates were tabulated and survival analysis was performed, stratified by salvage modality. Results: A total of 165 patients with R/R DLBCL who relapsed following ASCT were identified, of which, 91 patients received salvage chemotherapy as their first line of relapse therapy and 14 received salvage radiation. Median salvage RT dose was 36 Gy (range: 24-50). The objective response rate with salvage chemotherapy and RT was 53.0% and 78.5%, respectively (p=0.07), while complete response rate was 31.3% and 57.1%, respectively (p=0.06). Median follow-up among living patients was 48.9 months (range: 4.8-136.17). Among patients with one site of relapse post ASCT, median overall survival in patients who received salvage RT was significantly improved (p=0.008) relative to chemotherapy (not reached [95%CI: 8.4-NR] versus 10.0 months [95%CI: 5.3-17.8]). Median progression-free survival in patients who received salvage RT was not significantly different (p=0.16) relative to chemotherapy (8.4 months [95%CI: 2.5-47.7] versus 3.9 months [95%CI: 2.4-8.5]). Conclusions: Patients who received RT as first salvage therapy post ASCT, particularly with localized disease, had favorable oncologic outcomes. Future studies are needed to understand which patients with R/R DLBCL who relapse after ASCT may benefit from early salvage RT versus chemotherapy.
International Journal of Radiation Oncology, Biology, Physics 2022