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

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSION: The incidence of late dysphagia is similar in IMRT and CRT, but the mechanism of dysphagia is different.