Purpose: Aim of this study was to correlate dose to pharyngeal constrictors (PC) with subjective and observer-based assessments of swallowing in patients with head and neck cancer undergoing concomitant chemo-IMRT.
Materials and methods: Dose-volume histograms (DVHs) for superior constrictor (SC), middle constrictor (MC) and inferior constrictor (IC) were generated for 37 patients. Mean doses to SC, MC and IC were correlated to objective dysphagia grade (1 year, RTOG scoring) and global, total physical (TP) and most relevant components of the physical section (P6, P8) of the MD Anderson dysphagia inventory (MDADI) which was evaluated post-treatment. Odds ratios of dysphagia (>grade 0), poor global (<3), TP (<32), P6 (<3) and P8 (<3) for patients with mean dose>60 Gy to SC and IC were calculated.
Results: There was no significant correlation between mean dose to PC and any of the analysed MDADI parameters and observer-assessed dysphagia grade. Odds ratio of dysphagia (>grade 0), poor global (<3), TP (<32), P6 (<3) and P8 (<3) for patients with mean dose>60 Gy to IC and SC were not significantly higher than those for patients receiving <60 Gy.
Conclusion: This study did not find a statistically significant correlation between radiation dose to the PC and observer-assessed dysphagia grade or patient-reported MDADI questionnaire at 1 year.