Prospective swallowing outcomes after IMRT for oropharyngeal cancer: Dosimetric correlations in a population-based cohort.

OBJECTIVES: To identify dose constraints to preserve swallowing after head and neck (H&N) radiotherapy using prospectively collected functional outcomes.

MATERIALS AND METHODS: Stage III-IV oropharyngeal cancer patients were prospectively evaluated using the Royal Brisbane Hospital Outcome Measure for Swallowing and Performance Status Scale for H&N Cancer Patients at pre-treatment and 3, 6, 12, and 24months after intensity-modulated radiotherapy. Dosimetric parameters were correlated with swallowing function.

RESULTS: Ninety-six patients were evaluated with median follow-up of 14.1months (interquartile range 9.9-26.3). Six patients (8.3%) remained feeding tube (FT) dependent at 12months. At 2years, 32.6% tolerated a normal diet without restrictions. Mean doses of 55Gy to supraglottic larynx, 44Gy to glottic larynx, 48Gy to cricopharyngeus, and 44Gy to esophageal inlet were associated with >25% risk of FT dependence at 6months.

CONCLUSION: Higher mean doses to the larynx and pharyngo-esophageal junction were associated with longer duration of FT dependence and dietary restrictions.