Long-Term Patient-Reported Outcomes and Dosimetric Predictors of Quality of Life After Curative-Intent Radiation Therapy for Oropharyngeal Squamous Cell Carcinoma: A Cross-Sectional Study.

backgroundRadiation therapy (RT) is central to curative treatment for oropharyngeal squamous cell carcinoma (OPSCC) but may cause late side effects that can adversely impact quality of life (QOL). As OPSCC treatment becomes more personalised, clinically meaningful QOL endpoints and their predictors are increasingly important.

aimsTo assess long-term QOL, treatment regret, and predictors of QOL after curative-intent RT for OPSCC. METHODS AND

resultsThis cross-sectional survey included patients with primary OPSCC treated with curative intent RT between 2007 and 2023 at a single tertiary institution. Patients completed validated EORTC QOL questionnaires and additional items assessing perceived health and treatment regret. Survival outcomes were estimated using Kaplan-Meier methods, and compared by p16 status using log-rank test. QOL scores were analysed as continuous variables using univariate and multivariable linear regression models, with prespecified dosimetric predictors tested against clinically corresponding EORTC QOL-HN43 symptom scales and adjusted for multiple comparisons. Of the 344 patients treated, 274 (80%) had p16-positive disease. At median follow of 7.7 years, 5-year overall survival was 90% for p16-positive versus 52% for p16-negative disease, and disease-free survival 89% versus 72%. Of 232 patients contacted, 186 (80%) completed the QOL survey at median 6.3 years after RT. 173 (93%) reported no treatment regret regarding RT. Mean global health status was 81.3/100, while dry mouth/sticky saliva was the most affected domain (mean 41.9/100). On multivariable analysis, older age was associated with worse global health status (-4.9 points per 10 years, p = 0.001) and higher contralateral mean parotoid dose with worse dry mouth/sticky saliva scores (10.1 points per 10 Gy, 95% CI: 3.7 to 16.5, p = 0.002). Chemotherapy and prior surgery were not associated with any domain.

conclusionLong-term survivors of OPSCC reported favourable global QOL and little treatment regret after RT. However, dry mouth/sticky saliva remained a substantial burden, and more likely with higher contralateral parotid mean dose. These findings support ongoing contralateral parotid sparing and consideration of unilateral neck irradiation when oncologically appropriate, while recognising the cross-sectional cohort and need for rigorous prospective studies in this area.