Osteoradionecrosis as a complication following intensity-modulated radiation therapy or proton therapy in the treatment of oropharyngeal carcinoma.
Year: 2025
Type: conference-abstract
Abstract: 6066 Background: Osteoradionecrosis (ORN) is a late complication of head and neck radiotherapy (RT) that negatively impacts survivorship. Although there is an abundance of literature reporting on ORN for photon-based RT, few studies have investigated the correlation between proton therapy and ORN; also, the current literature on ORN incorporates a broad mix of head and neck subsites. Therefore, we report our 10-year institutional experience to assess rates of ORN in a homogenous and consecutive cohort of patients with oropharyngeal squamous cell carcinoma (OPSCC) treated with curative-intent radiotherapy, representing the largest available institutional series. Methods: A consecutive cohort of 1564 OPSCC patients (1344 definitive, 220 post-operative) who received at least 50Gy were treated at our institution between 2013 and 2023 were included in this study. Patients were treated with either IMRT or proton therapy. CTCAE version 5 was used for ORN grading. Results: Overall ORN rate was 4.35%. Of 1389 patients who underwent IMRT, 56 (4.03%) developed ORN, vs 12/175 (6.86%) treated with proton therapy (hazard ratio [HR] 2.62, 95%CI 1.39–4.93, P=0.003). Median time to ORN in the IMRT arm was 25mo (range, 2mo–91mo). Median time to ORN in the proton arm was 23.5mo (2mo–45mo). Post-operative vs definitive treatment setting was not associated with the rate of ORN (univariate Cox HR 1.00, 95% CI 0.51–1.95, P=0.99). On subset analysis of the 1344 patients treated in the definitive setting, 47/1210 (3.88%) patients treated definitively with IMRT developed ORN as compared to 11/134 (8.21%) patients treated definitively with protons (univariable Cox HR 3.62, 95% CI 1.85–7.09, P<0.001). On multivariable analysis including treatment modality and use of chemotherapy, proton therapy was associated with increased hazard of ORN (HR 2.75, 95%CI 1.46–5.19, P=0.002). Concurrent chemotherapy was also independently associated with increased hazard of ORN (HR 3.34, 95%CI 1.05–10.65, P=0.041). A total of 10 out of 1564 (0.64%) patients developed CTCAE grade 3 ORN. The rates of grade 3 ORN were 2/175 (1.14%) in the proton cohort and 8/1389 (0.58%) in the IMRT cohort. This difference was not statistically significant on univariable Cox analysis (HR 2.44, 95%CI 0.51–11.60, P=0.26). Conclusions: The overall prevalence of ORN was 4.35%; the prevalence of >/= grade 3 ORNs was 0.64% in this consecutive cohort of patients with OPSCC treated with either IMRT or proton therapy. The overall prevalence of ORN of any grade was statistically higher for protons versus IMRT, a difference that was more pronounced in the definitive setting. Given the uncertainties with relative biological effectiveness calculations in proton therapy, avoidance of hot-spots, frequent replanning, and use of empirical proton-specific normal tissue constraints may help to reduce rates of ORN. Future work should explore the role of combination proton and photon treatment, especially in the definitive setting.
Source: Journal of Clinical Oncology
Authors: Edward Christopher Dee, Fan Yang, Annu Singh, Yingzhi Wu, James Suggitt, Teeradon Treechairusame, Elizabeth Silverio Polanco, Zhigang Zhang, Dennis Mah, Haibo Lin, Sean Matthew McBride, Nadeem Riaz, Daphna Y. Gelblum, Yao Yu, Ian Ganly, Eric Jeffrey Sherman, Alan Loh Ho, Richard J. Wong, Cherry Estilo, Nancy Y. Lee
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W4410805002