Comparison of 36 Gy, 20 Gy, or No Radiation Therapy After 6 Cycles of EBVP Chemotherapy and Complete Remission in Early-Stage Hodgkin Lymphoma Without Risk Factors: Results of the EORT-GELA H9-F Intergroup Randomized Trial

Abstract

While patients with early-stage Hodgkin lymphoma (HL) have an excellent outcome with combined treatment, the radiation therapy (RT) dose and treatment with chemotherapy alone remain questionable. This noninferiority trial evaluates the feasibility of reducing the dose or omitting RT after chemotherapy. Patients with untreated supradiaphragmatic HL without risk factors (age≥50years, 4 to 5 nodal areas involved, mediastinum-thoracic ratio≥0.35, and erythrocyte sedimentation rate≥50mm in first hour without B symptoms or erythrocyte sedimentation rate≥30mm in first hour with B symptoms) were eligible for the trial.Patients in complete remission after chemotherapy were randomized to no RT, low-dose RT (20Gy in 10 fractions), or standard-dose involved-field RT (36Gy in 18 fractions). The limit of noninferiority was 10% for the difference between 5-year relapse-free survival (RFS) estimates. From September 1998 to May 2004, 783 patients received 6 cycles of epirubicin, bleomycin, vinblastine, and prednisone; 592 achieved complete remission or unconfirmed complete remission, of whom 578 were randomized to receive 36Gy (n=239), 20Gy of involved-field RT (n=209), or no RT (n=130). Randomization to the no-RT arm was prematurely stopped (≥20% rate of inacceptable events: toxicity, treatment modification, early relapse, or death). Results in the 20-Gy arm (5-year RFS, 84.2%) were not inferior to those in the 36-Gy arm (5-year RFS, 88.6%) (difference, 4.4%; 90% confidence interval [CI] -1.2% to 9.9%). A difference of 16.5% (90% CI 8.0%-25.0%) in 5-year RFS estimates was observed between the no-RT arm (69.8%) and the 36-Gy arm (86.3%); the hazard ratio was 2.55 (95% CI 1.44-4.53; P<.001). The 5-year overall survival estimates ranged from 97% to 99%. In adult patients with early-stage HL without risk factors in complete remission after epirubicin, bleomycin, vinblastine, and prednisone chemotherapy, the RT dose may be limited to 20Gy without compromising disease control. Omitting RT in these patients may jeopardize the treatment outcome.