Osteoradionecrosis in Pediatric Patients Treated with Proton Therapy for Head and Neck Malignancies

Purpose: Osteoradionecrosis (ORN) is a feared complication after head and neck (H/N) radiation, but the incidence and radiation therapy risk factors for ORN in children are unknown. In this retrospective analysis of a prospectively collected data set, we evaluated the incidence and factors associated with the development of ORN in children treated with proton therapy (PT) for H/N malignancies. Materials and Methods: We reviewed records from patients treated at a single institution between December 2006 and February 2020, including demographic data, tumor, treatment details, ORN occurrence, and dosimetry. Results: We identified 117 pediatric patients treated with PT for H/N malignancies. The most common histology was rhabdomyosarcoma (46%), and the most common involved sites were the parameningeal sites (44%) and the orbit (32%). The majority received passive scatter (n = 81, 69%) and the remainder intensity modulated PT (n = 36, 31%). Only 2 (1.7%) developed ORN. Both patients had previous dental work and high radiation doses to the affected bone. Patient 1 had a maximum and mean dose to the affected bone of 68 and 42 Gy, while patient 2 received 64.2 and 56.4 Gy, respectively. Conclusions: ORN was uncommon in our large, single institution cohort, occurring in only 1.7% of pediatric patients treated with PT for H/N malignancies.