Resident Physician New York University Grossman School of Medicine New York, New York
Background/Objectives: Base of tongue (BOT) dysfunction is common following oropharyngeal concurrent chemoradiation therapy (CCRT) and is associated with dysphagia, malnutrition, and aspiration. We present a clinically relevant model quantifying effects of CCRT on BOT strength over time.
Methods: Fifty-two male and 52 female Sprague-Dawley rats were randomized to control or experimental groups. Experimental animals received cisplatin, 5-fluorouracil and 5 fractions of 7 Gy directed to the BOT. Controls received no intervention. At 2 weeks, 5 months, or 10 months after CCRT, animals underwent non-survival surgery to measure twitch and tetanic tongue strength, which were analyzed using linear mixed effects models accounting for sex, weight, time point, experimental group, and their interaction.
Results: No differences in tongue strength were detected between sexes, or at 2 weeks after CCRT. Estimated experimental group mean peak twitch forces were 16.4% lower than controls at 5 months (mean 178 mN, 95% CI [159-197] vs. mean 213 mN, 95% CI [194-232]) and 32.4% lower at 10 months (mean 167 mN, 95% CI [150-185] vs. mean 247 mN, 95% CI [228-266]). Estimated experimental group mean peak tetanic forces were 20.8% lower than controls at 5 months (mean 691 mN, 95% CI [632-750] vs. mean 873 mN, 95% CI [812-934]) and 26.7% lower at 10 months (mean 702 mN, 95% CI [647-756] vs. mean 958 mN, 95% CI [897-1019]).
Conclusions: This study demonstrates decreasing tongue strength over time following BOT CCRT in an animal model, mimicking the functional decline of many CCRT patients and facilitating understanding of oropharyngeal CCRT sequalae.