Accelerated three-dimensional conformal radiotherapy for early-stage glottic cancer in reducing dose to the internal carotid artery and pharyngeal constrictor muscles

Background We evaluated clinical and dosimetric outcomes of radiotherapy using two anterior oblique portals (AOP), to reduce the dose to the bilateral internal carotid arteries (CAs) and pharyngeal constrictor muscle (PCM) during early-stage glottic cancer (ESGC) treatment.Methods We identified patients with ESGC who underwent definitive radiotherapy between June 2014 and May 2020.Results Among the 66 patients, 32 (48%) underwent radiotherapy using AOP, and the remaining underwent typical radiotherapy using parallel opposed lateral portals (POLP). The median follow-up duration was 53 months. No significant differences were observed in the 5-year local failure (0%/9.4%), progression-free survival (90.6%/90.8%), and overall survival (90.6%/91.0%) rates between the two groups. The grade >= 2 acute mucositis incidence rate was significantly lower in the AOP group (44%/85%). Radiotherapy using AOP maintained an adequate dose coverage to the target while markedly reducing the CAs and PCM doses.Conclusion Radiotherapy with AOP resulted in favorable clinical and dosimetric outcomes.