Phase II Study of Dose-Reduced Consolidation Radiation Therapy in Diffuse Large B-cell Lymphoma
Mené sur 62 patients atteints d'un lymphome diffus à grandes cellules B et ayant reçu une chimiothérapie de type R-CHOP ou R-EPOCH (durée médiane de suivi : 51 mois), cet essai de phase II évalue, du point de vue de l'absence de récidive locale à 5 ans, la possibilité de réduire la dose de rayonnements d'une radiothérapie de consolidation
Purpose : To evaluate the feasibility of reducing the dose of consolidation radiation therapy (RT) in diffuse large B-cell lymphoma (DLBCL). Patients and Methods : This phase II study enrolled patients with DLBCL not otherwise specified, and primary mediastinal (thymic) large B-cell lymphoma in complete response (CR) by PET-CT after ≥ 4 cycles of a rituximab/anthracycline-containing combination chemotherapy regimen. Consolidation RT utilized a dose of 19.5-20 Gy. The primary endpoint was 5-year freedom from local recurrence. Results : 62 patients were enrolled between 2010 and 2016. Stage distribution: I-II (n=49, 79%) and III-IV (n=13, 21%). Bulky disease (defined as ≥7.5 cm or ≥ 10 cm) was present in 23 (40%) and 16 (28%) of patients, respectively. Chemotherapy was R-CHOP in 58 (94%) and R-EPOCH in 4 (6%) with a median of 6 cycles. With a median follow-up of 51 months, 7 patients developed disease progression (6 outside the RT field, 1 within the RT field). Freedom from local recurrence at 5 years was 98% (90% lower confidence bound, 88%). Progression-free and overall survival at 5 years were 83% and 90%, respectively. Conclusion : With more effective systemic therapy (e.g., addition of rituximab), and more refined chemotherapy response assessment (e.g., PET-CT), the dose of RT in combined modality treatment programs may be able to be reduced to 20 Gy. This achieves excellent local control with the potential to decrease acute and long-term side effects.
https://www.redjournal.org/article/S0360-3016(19)30313-X/fulltext 2019