Reducing posttreatment dysphagia: Support for the relationship between radiation dose to the pharyngeal constrictors and swallowing outcomes

Jacqui Frowen, Colin Hornby, Marnie Collins, Sashendra Senthi, Robin Cassumbhoy, June Corry

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11 Citations (Scopus)

Abstract

Purpose: This study used prospective swallowing data to establish the following: (1) whether doses to the pharyngeal constrictor muscles (PCMs) were significantly associated with swallowing outcomes; and (2) a mean dose constraint to aim for in intensity modulated radiation therapy planning. Methods and Materials: The PCMs were contoured and radiation dose data obtained for 55 patients with head and neck cancer. Associations between radiation dose and percentage of pharyngeal residue, penetration-aspiration and activity limitation measured at 6 months posttreatment were analyzed. Pretreatment swallowing function, tumor site, T classification, and chemotherapy were accounted for in multivariate analyses. Results: On multivariate analysis, the percentage of pharyngeal residue was statistically significantly associated with the mean dose to the superior PCM (95% confidence interval [CI], 0.15-1.66; P = .02). Penetration-aspiration was associated with the mean dose to the superior, middle, and inferior PCMs (95% CI, 1.02-1.27; P = .003; 95% CI, 1.02-1.23; P = .003; 95% CI, 1.04-1.21; P = .003, respectively) and the mean dose to the total PCM (95% CI, 1.05-1.31; P = .001). Activity limitation was also associated with the mean dose to the superior, middle, and inferior PCMs (95% CI, 1.01-1.20; P = .02; 95% CI, 1.00-1.15; P = .04; 95% CI, 1.01-1.15; P = .02, respectively) and the mean dose to the total PCM (95% CI, 1.02-1.23; P = .01). On univariate analysis, all 3 swallowing measures were statistically significantly worse for patients who received a biologically equivalent mean dose of >. 60 Gy to the PCMs. This remained significant on multivariate analysis for both penetration-aspiration and activity limitation (95% CI, 2.05-58.2, P = .004 and 95% CI, 1.14-27.7, P = .03, respectively). Conclusions: The radiation dose to the PCMs is significantly associated with swallowing dysfunction. Limiting the mean PCM dose to less than 60 Gy results in better swallowing outcomes.

Original languageEnglish
Pages (from-to)e187-e194
Number of pages8
JournalPractical Radiation Oncology
Volume3
Issue number4
DOIs
Publication statusPublished - Oct 2013
Externally publishedYes

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