The Utility of PET/CT in Guiding Radiotherapy Reduction for Children With Hodgkin Lymphoma Treated With ABVD.

ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) is standard upfront chemotherapy for adults diagnosed with Hodgkin lymphoma (HL), but positron emission tomography (PET)-based response data following ABVD is lacking for pediatrics. Among children who received ABVD for HL, we document interim and end of therapy PET-computed tomography (CT) response by Deauville criteria, and survival outcomes following a response-based reduction in involved field radiotherapy (IFRT). Children 18 years of age or below with HL treated with ABVD between 2006 and 2015 who had interim PET/CT scans after 2 cycles of chemotherapy were included. Interim and end of therapy PET/CT scans were retrospectively re-evaluated using Deauville criteria by 3 radiologists. Among 45 children, 32 (71%) met criteria for intermediate risk, 86% achieved rapid early response (RER) and only 4 (9%) received upfront IFRT. Patients achieving RER had superior 5-year event-free survival (EFS) 95%±4% versus 50%±18% (P≤0.001) and overall survival (OS) 100% versus 83%±15% (P=0.025). Patients with bulk who achieved RER and received no IFRT achieved 5-year EFS of 92%±6% and OS 100%. Low, intermediate, and high risk patients had 5-year EFS of 100%, 94%±4%, and 50%±18% (P=0.002) and 5-year OS of 100%, 100%, and 75%±15% (P=0.03). RER following 2 cycles of ABVD is predictive of survival outcomes in children and adolescents with HL and may identify a group who may omit IFRT.