Patterns of failure after involved field radiation therapy for pediatric and young adult Hodgkin lymphoma

Background: Involved field radiation therapy (IFRT) is integral in curative therapy for Hodgkin lymphoma (HL), although primarily used in patients with intermediate/high-risk HL. We present failure patterns and clinical outcomes in a cohort of pediatric and young adult patients with HL treated with IFRT at the Johns Hopkins Hospital. Procedure: Patients ≤40 years old with intermediate/high-risk HL who received chemotherapy and IFRT from 1997 to 2012 were included in this retrospective analysis. Patients were evaluated for failure patterns, overall survival (OS), and event-free survival (EFS) using Kaplan-Meier curves, descriptive statistics, and Cox proportional hazard regressions. Results: We reviewed 74 patients (45 pediatric and 29 young adult) with a median follow-up of 4.4 years. The mean age at diagnosis was 21.4 years. Patients received a median of 29.75Gy of IFRT (range 15-39.6Gy). The majority of pediatric patients received ABVE-PC chemotherapy (n=25) and <30Gy of radiation (n=33) while most young adults received ABVD chemotherapy (n=24) and ≥30Gy (n=25). Estimated 5-year OS and EFS were 96% and 81%, respectively. Thirteen patients had recurrence; eight were pediatric. Distant relapse alone comprised 83% of failures in patients receiving ≥30Gy. Of the seven patients who received <30Gy and had recurrence, six had local failure as a component of their recurrence. Caucasian race (P=0.02) and nodular sclerosing histology (P=0.01) predicted for increased EFS. Late effects were minimal and all deaths (n=4) were from HL. Conclusions: In this series, pediatric and young adult patients were treated with differing chemoradiation and had distinct recurrence patterns. Pediatr Blood Cancer 2014;61:1210-1214.