Analysis of pharyngeal edema post-chemoradiation for head and neck cancer: Impact on swallow function

Objectives Edema is a frequent clinical observation following chemoradiation treatment (CRT) of oral/oropharyngeal cancer and is thought to contribute to post-CRT swallowing impairment. Our aims were to reliably quantify pharyngeal edema pre- and post-CRT from videofluoroscopic (VF) swallowing studies and to explore the relationship between edema and swallowing impairment. Swallowing impairment was captured using patient-reported swallowing outcomes (EAT-10) and with VF confirmation of impairment (DIGEST). Methods 40 patients (24 M, age 38-76) with oral/oropharyngeal cancer received radiotherapy (70 Gy, 7 weeks) and 3 weekly doses of cisplatin. VF and EAT-10 were completed pre- and 1-month post-CRT. Edema was captured by measuring posterior pharyngeal wall (PPW) thickness, vallecular space, and pharyngeal area (PA) on a single post-swallow rest frame. Wilcoxon sign rank tests and paired t-tests evaluated within-subject changes in impairment and edema respectively. A linear mixed effect regression model explored the influence of time, patient-reported outcomes, and functional impairment on measures of edema. Results Swallowing function (EAT-10 and DIGEST) was significantly worse post-CRT. PPW thickness (but not vallecular space and pharyngeal area) was significantly worse post-CRT. PPW thickness was only significantly influenced by time (pre- vs. post-CRT) but not by measures of swallow function. Conclusion Our findings establish the use of PPW thickness as a reliable measure of acute edema in post-CRT treatment. In this small, retrospective sample, edema was not significantly correlated with either patient-reported or measured swallow function. Prospective longitudinal work, examining the relationship between objective measures of edema, patient perception of impairment, and swallow function and biomechanics is warranted.