Patient- and Clinician-Reported Outcomes in Human Papillomavirus-Associated Tonsillar Carcinoma Treated With Unilateral and Bilateral Intensity Modulated Radiation Therapy–A Substudy From TROG 12.01

The aim of this TROG 12.01 substudy was to report longitudinal variations in patient- (PRO) and clinician-reported outcomes based on receipt of unilateral (URT) or bilateral radiation therapy (BRT). Patients with lateralized T1-2 N1-2b human papillomavirus-associated tonsillar carcinoma (AJCC7) enrolled on TROG 12.01 were eligible. The primary endpoint was patient-reported radiation symptom severity score (MDASI-RSS) at 2 years, a composite of 9 MDASI-Head and Neck (HN) symptom items. Secondary endpoints included patient-reported symptom burden and interference (MDASI-HN), quality of life (FACT-HN), emotional distress (HADS), return to work (RTW), clinician-reported performance status scale (PSS-HN), and late adverse events (CTCAE). Mean MDASI-RSS, symptom severity (MDASI-SS), symptom interference (MDASI-SI) and selected single items were compared 1 week, 3 months, and 2 years post-RT. Seventy-four patients were eligible for analysis (26 URT, 48 BRT). Median follow-up was 3.7 years (1.8-5.2 years). Sociodemographic, staging, and treatment variables were mostly balanced, with larger primaries observed in the BRT group. Four regional failures were reported (3 URT, 1 BRT), including one isolated contralateral regional failure in the URT cohort. Mean MDASI-RSS scores did not differ at 2 years (URT vs BRT, 1.1 vs 1.3; difference 0.1 [95% CI: –0.7 to 0.9], P = .75) or at any other time points for the MDASI-RSS, MDASI-SS, and MDASI-SI scores, except for worse MDASI-SI 1 week after treatment in the BRT group (4.7 vs 5.6). Fatigue (6.6 vs 5.4) at 1 week and dry mouth (3.5 vs 2.0) at 2 years were also worse in the BRT group. FACT-HN, HADS, RTW, PSS-HN, and CTCAE results were similar across the follow-up period. In this favorable-risk cohort, treatment laterality resulted in fewer differences than anticipated in patient-reported or clinician-reported outcomes. Two years after treatment patients treated with BRT reported significantly worse dry mouth. Longer follow-up is needed to determine the impact of treatment laterality on late effects.