Retrospective cohort study of osteoradionecrosis after intensity-modulated radiation therapy or proton therapy in oropharyngeal carcinoma

Osteoradionecrosis (ORN) is a potentially debilitating late complication of radiotherapy for head and neck cancer. While proton therapy offers superior dose conformality, its impact on ORN risk is uncertain, particularly in patients with oropharyngeal squamous cell carcinoma (OPSCC). A retrospective cohort study at Memorial Sloan Kettering Cancer Center (New York, NY) investigated the incidence, seveity, and predictors of ORN in patients with OPSCC treated with curative-intent proton therapy or intensity-modulated radiation therapy (IMRT). In this study of 1564 patients, the 3-year incidence of ORN was 3.0%. Proton therapy was associated with higher ORN rates compared with IMRT (6.4% versus 2.7% at 3 years), while high-grade ORN remained rare (approximately 1%) and did not differ by modality. The authors conclude that proton therapy for OPSCC was associated with increased ORN risk, underscoring the need for refined dose constraints and treatment planning to mitigate late effects.