The benefit of consolidation radiotherapy to initial disease bulk in patients with advanced Hodgkin's disease who achieved complete remission after standard chemotherapy

Abstract

Yasser Bayoumi,1,2 Abdulaziz Al-Homaidi,3 Syed Zaidi,3 Imran Tailor,3 Ibrahiem Motiabi,3 Nawal Alshehri,3 Assem Al-Ghazali,3 Samer Almudaibigh3 1Radiation Oncology, National Cancer Institute, Cairo University, Egypt; 2Radiation Oncology Department, 3Department of Haematology and Oncology, Comprehensive Cancer Center, King Fahad Medical City, Riyadh, Saudi Arabia Background/purpose: The aim of this study was to evaluate the role of consolidation radiotherapy (RT) in advanced-stage Hodgkin's disease (HD) with initial bulky sites after radiological complete remission (CR) or partial response (PR) with positron emission tomography-negative (metabolic CR) following standard chemotherapy (ABVD [Adriamycin, bleomycin, vinblastine, and dacarbazine]) six to eight cycles. Patients and methods: Adult patients with advanced-stage HD treated at our institute during the period 2006 to 2012 were retrospectively evaluated. One hundred and ninety-two patients with initial bulky disease size (>7 cm) who attained radiological CR/PR and metabolic CR were included in the analysis. One hundred and thirteen patients who received radiotherapy (RT) as consolidation postchemotherapy (RT group) were compared to 79 patients who did not receive RT (non-RT group). Disease-free (DFS) and overall survival (OS) rates were estimated using the Kaplan–Meier method and were compared according to treatment group by the log-rank tests at P ≤0.05 significance level. Results: The mean age of the cohort was 33 (range: 14 to 81) years. Eighty-four patients received involved-field radiation and 29 patients received involved-site RT. The RT group had worse prognostic factors compared to the non-RT group. Thirteen (12%) relapses occurred in the RT group, and 19 (24%) relapses occurred in the non-RT group. Nine patients (8%) in the RT group died, compared to eleven patients (14%) in the non-RT group. Second malignancies were seen in only five patients: three patients in the RT group compared to two patients in the non-RT group. At 5 years, overall DFS was 79%±9% and OS was 85%±9%. There was significant statistical difference between the RT group and the non-RT group regarding 5-year DFS: 86%±7% and 74%±9%, respectively (P ≤0.02). However, the 5-year OS was 90%±5% for the RT group and 83%±8% for the non-RT group, with no statistical difference (P ≤0.3). Conclusion: The results of our study suggest that consolidation RT in patients with advanced-stage HD with initial bulky disease who had postchemotherapy radiologic CR or PR with metabolic CR improved the DFS. Keywords: Hodgkin's disease, radiological and metabolic complete remission, involved-field radiation, involved-site radiation