3603 - Predictors of Patient-Reported Dysphagia after Transoral Robotic Surgery and De-Intensified Adjuvant Radiation Therapy for HPV-Associated Oropharyngeal Squamous Cell Carcinoma
Presenter(s)
M. D. Riina1, A. Ramkissoon1, A. Giron2, M. S. Gentile3, R. J. L. Maxwell2, E. J. Ojerholm4, D. Basu4, R. Brody4, S. B. Cannady5, R. M. Carey5, A. Chalian5, K. Rajasekaran5, C. Rassekh5, G. S. Weinstein5, R. Cohen6, A. Singh6, L. Sun4, K. Montone4, A. Lin2, and J. N. Lukens4; 1Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, 2Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 3Massachusetts General Hospital; University of Pennsylvania, Department of Radiation Oncology, Boston, MA, 4University of Pennsylvania, Philadelphia, PA, 5Department of Otorhinolaryngology: Head and Neck Surgery, University of Pennsylvania, Philadelphia, PA, 6Department of Hematology and Oncology, University of Pennsylvania, Philadelphia, PA
Purpose/Objective(s): De-intensified adjuvant radiation therapy (DI-aRT) after transoral robotic surgery (TORS) for HPV+ oropharyngeal squamous cell carcinoma (OPSCC) may reduce treatment-related toxicity while preserving excellent oncologic outcomes. However, data characterizing predictors of patient-reported dysphagia following treatment with this approach remain limited.
Materials/Methods: As part of an institutional, single-arm Phase II study of DI-aRT after TORS for HPV+ OPSCC including both dose de-escalation (50/45Gy) and target volume reduction with selective omission of the oropharyngeal resection bed (primary site) and contralateral low neck, patients completed the MD Anderson Symptom Inventory (MDASI-HN) prior to RT, at the end of RT, and 3, 6, 12, 18, and 24 months after completion of RT. Linear mixed models were used to evaluate dysphagia symptom scores (0-10) from the end of RT to 24 months post RT incorporating time (continuous) and a single covariate as fixed effects and patients as random effects. Covariates demonstrating association at p<0.1 on univariable analysis were analyzed together as main effects along with demographics (age and sex) in a multivariable linear mixed model.
Results: Among 149 patients treated per protocol, MDASI completion rates at each timepoint were: End of RT-74%, 3 months-68%, 6 months-68%, 12 months-60%, 18 months-56%, and 24 months-47% respectively, with 81% completing at least one long-term survey (12-24 months). Linear mixed models of single covariates showed significant association of increased patient-reported dysphagia with targeting of the primary site (ß=1.2 [95% CI: 0.5-1.9], p<0.01), free flap reconstruction (ß=1.0 [95% CI: 0.1-2.0], p<0.05), mean dose to the pharyngeal constrictors (ß=0.8/10Gy [95% CI: 0.2-1.4/10Gy], p<0.01), and mean dose to the bilateral parotid glands (ß=1.7/10Gy [95% CI: 0.6-2.8/10Gy], p<0.01). Additional covariates that were not statistically significant, but have clinical relevance, were primary tumor site (Tonsil v. BOT/BOT+Tonsil/unknown primary) (ß=0.7 [95% CI: -0.04-1.4], p=0.07) and receipt of chemotherapy (ß=0.8 [95% CI: -0.1-1.6], p=0.08). Covariates that remained significant in the multivariable model included treating the primary site (ß=0.9 [95% CI: 0.1-1.7], p<0.05), and mean dose to the bilateral parotid glands (ß=1.4/10Gy [95% CI: 0.3-2.6/10Gy], p<0.05). Free flap reconstruction (ß=0.8 [95% CI: -0.1-1.7], p=0.1) and mean dose to the pharyngeal constrictors (ß=0.05/10Gy [95% CI: -0.6-0.8, p=0.9) did not maintain statistical significance in the multivariable model.
Conclusion: Among patients with HPV+ OPSCC treated with TORS and DI-aRT including both dose and volume reduction, targeting of the primary site and higher mean dose to the bilateral parotids are associated with greater patient reported dysphagia symptom severity. As a component of DI-aRT, selective omission of the primary site may reduce the swallowing-related morbidity of primary surgical management of HPV+ OPSCC.