Late dysphagia after IMRT for head and neck cancer and correlation with dose-volume parameters

Many head and neck cancer (HNC) survivors experience diminished quality of life due to radiation-induced dysphagia. The aim of this study was to investigate frequency, intensity and dose-volume dependency for late dysphagia in HNC patients treated with curative IMRT.

Candidates for the study were 294 patients treated with primary IMRT from 2006 to 2010; a total of 259 patients accepted to participate by answering the EORTC QLQ-C30 and H&N35 questionnaires. A total of 65 patients were further examined with modified barium swallow (MBS) and saliva collection. Data on patient, tumor and treatment characteristics were prospectively recorded in the DAHANCA database. Dose-volume histograms (DVH) of swallowing-related structures were retrospectively analyzed.

QoL data showed low degree of dysphagia (QoL subscales scores of 17 and below) compared to objective measures. The most frequent swallowing dysfunction was retention; penetration and aspiration was less common. In general, objective measurements and observer-assessed late dysphagia correlated with dose to pharyngeal constrictor muscles (PCM), whereas QoL endpoints correlated with DVH parameters in the glottis/supraglottic larynx. Both xerostomia and dysphagia has been reduced after introduction of IMRT.

Radiation-induced dysphagia is still important, with a high degree of retention and penetration. Introduction of parotid-sparing IMRT has reduced the severity of dysphagia, primarily through a major reduction in xerostomia. Dose-response relationships were found for specific dysphagia endpoints.