Comparative Analysis of Response-Adapted Radiotherapy in Patients with Early-Stage Hodgkin Lymphoma

Introduction : Consolidative radiotherapy (RT) in upfront management of patients with early-stage classic Hodgkin lymphoma (cHL) may differ widely among clinical institutions. While some centers routinely apply RT, others adopt response-adapted approach. Patients and methods : This multicenter retrospective study assessed real-world outcomes of patients with early-stage cHL diagnosed between 2011 to 2022 and compared PET-adapted RT vs routine RT to all. Primary focus was on key outcomes, including overall survival (OS), complete metabolic remission (CMR) and relapse rates. Results: A total of 490 patients (median age of 27 years) with stage I-II were included. RT was routinely applied after end of chemotherapy in 57.8%. CMR was achieved in 90.4% and 90.8% in RT and no-RT arm respectively. Overall, 42 relapses occurred (23 with RT and 19 without). Among patients achieving CMR following first-line chemotherapy, 57% received RT. In this CMR group, 5-years OS (p = 0.95) and relapse rates (p = 0.92) were not statistically significant. However, RT converted 33.3% of patients with positive EOT-PET to PET negative. Conclusions : Our real-world data suggests that routine consolidation with RT may be omitted for patients with early-stage cHL who achieved negative EOT-PET. However, for patients with positive EOT-PET, consolidative RT helps curing substantial proportion of these individuals.