Adjuvant Proton Radiation Following Transoral Robotic Surgery for HPV-Positive Oropharyngeal Squamous Cell Carcinoma.

Objective: Advances in the treatment of human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) include transoral robotic surgery (TORS) and proton beam therapy (PBT). This study aims to improve understanding of the treatment toxicities associated with adjuvant PBT following TORS for OPSCC.

Methods: A retrospective review. Methods: An academic tertiary care center in Baltimore, Maryland. Methods: Patients undergoing TORS followed by adjuvant PBT from 2017 to 2023 were reviewed.

Results: Forty-seven patients with HPV-associated OPSCC underwent TORS followed by adjuvant PBT. Forty-one (87.2%) patients were male. The median age at first radiation fraction was 61.7 years. Forty-one (87.2%) identified as white and 6 (12.8%) as African American. Most patients had T1 (23 [48.9%]) or T2 (22 [46.8%]), N1 (41 [87.2%]) disease. The majority (98.3%) of acute toxicities were grade 1 or 2, with only 1 (2.1%) patient developing grade 3 toxicities. Three (6.4%) patients required a feeding tube for nutrition during adjuvant proton radiation treatment. The 3 patients who required feeding tubes during radiation also required postoperative nasogastric tubes for a median of 16 days, compared with 3 days for all other patients (Mann-Whitney U, P = .02). The most common chronic toxicities included xerostomia, dysphagia, dysgeusia, and lymphedema, which decreased over time.

Conclusions: HPV-associated OPSCC treated with TORS followed by adjuvant PBT demonstrated a favorable toxicity profile with mostly grade 1 or 2 acute toxicities. Feeding tube requirement during adjuvant PBT was low at 6.4%. Many chronic toxicities appeared to decrease in frequency with time from radiation, although further study is required.