Characteristics of Premature Radiotherapy Terminations in Patients with Oral Cavity and Laryngeal Carcinomas

Abstract

Premature radiation therapy (RT) terminations in patients with head and neck cancer result in poor outcomes. However, the underlying factors that contribute to early RT termination are understudied, especially in the era of hypofractionated treatment. In this retrospective single institution study, we examined causes and clinical characteristics of premature terminations in oral cavity (OC) and laryngeal carcinomas. We reviewed charts of 188 patients treated with RT ± systemic therapy for OC and laryngeal cancer from 2017-2022. Patients were typically prescribed standard 1.8-2.0 Gy fractionation regimens, though patients deemed unlikely to complete conventional RT upon initial evaluation were given SBRT. Premature termination was defined as completion of less than 95% prescribed RT. We collected pertinent demographic, clinicopathological data on this termination cohort, which was compared to a matched cohort of patients with RT completion. We used logistic regression analysis to examine factors predictive of premature termination. Of the patients included in this analysis, 72.7% were prescribed adjuvant RT [9.1% OC, 45.5% larynx] vs. 27.3% primary RT [90.9% OC, 45.5% larynx]. 84.6% received conventional IMRT, while 15.4% received SBRT. 17 patients (9.0%) had premature RT (all IMRT) terminations- 9 OC and 8 laryngeal primaries. Mean age of those who had premature termination was 79.5 years (range: 70-98). 70.6% were male, 58.8% were white, and 23.5% were single/widowed. Majority received concurrent systemic therapy (58.8%), had AJCC (8th Ed.) Stage ≥ III (76.5%), Charlson-Comorbidity Index ≥6 (64.7%), ECOG score ≥2 (70.6%), smoked >10 pack-years (76.5%), and lived >10 miles from RT facility (58.8%). The most common documented reasons for premature termination were: subjective intolerance (29.4%), death (23.5%), objective RT toxicity (23.5%), and inpatient admission (17.6%). The mean time on treatment for IMRT was 27.8 days for termination cohort vs. 47.7 days for completion cohort. The percentage of patients reporting RT toxicity (CTCAE v5.0 mucositis, severe weight loss, oral infection, e.g.) was 88.2% for termination cohort vs. 29.6% for completion cohort. On regression analysis, ECOG score at the time of initiation of RT was independently associated with premature termination (OR: 2.438, 95% CI: 1.155-5.146, p = .019). This retrospective analysis of patients undergoing RT for OC and laryngeal cancers at our tertiary care center demonstrated nearly 1 in 10 patients are at risk for premature termination. Poor performance status was independently associated with premature termination. There was a 100% completion rate in hypofractionated treatment with SBRT. Taken together, poor performance status may identify patients at risk for premature termination and thus identify good candidates for SBRT protocols.