Intensity-modulated versus conventional radiation therapy for oropharyngeal carcinoma: long-term dysphagia and tumor control outcomes.

Abstract

The purpose of this study was to determine the relative clinical benefits of intensity-modulated radiation therapy (IMRT) versus conventional radiotherapy (CRT) in the treatment of patients with oropharyngeal carcinoma. We compared tumor control and toxicity outcomes in 132 patients with stage III to IVA/B oropharyngeal carcinoma treated with definitive chemoradiation in the human papillomavirus (HPV) era. Patients treated with IMRT had lower rates of xerostomia (p = .01) and shorter duration of gastrostomy-tube dependence (p < .0001), but increased risk of cervical esophageal stricture (p = .03). The overall rates of late dysphagia were not different between the 2 groups (p = .40). In multivariate analysis, IMRT was a significant predictor of decreased disease-specific mortality (hazard ratio [HR] = 0.24; p = .03) after adjustment for T-category and active smoking. After adjustment for T classification, IMRT use was associated with a trend toward a significant decrease in locoregional failure (HR = 0.17; p = .08). The incidence of late dysphagia is similar in IMRT and CRT, but the mechanism of dysphagia is different.