Longitudinal Analysis of Swallowing Displacement Kinematics After Oropharyngeal Cancer Treatment

Background/objective: Quantitative swallowing displacement kinematics evolve in patients treated for oropharyngeal squamous cell carcinoma (OPSCC). We aimed to longitudinally assess these measurements and correlate them with functional swallowing outcomes.

Method: A retrospective review was conducted on patients with OPSCC treated with definitive (chemo)radiation ([C]RT) or surgery with adjuvant (chemo)radiation (S-[C]RT) who completed at least two videofluoroscopic swallow studies (VFSS). Longitudinal analysis was accomplished via mixed-effects logistic regression for the Functional Oral Intake Scale (FOIS), and Penetration Aspiration Scale (PAS), and mixed-effects linear regression for kinematic measures. Spearman's correlation was conducted between changes in FOIS/PAS and kinematic measures.

Results: Ninety-seven patients (76 males; mean age 61) completed 245 VFSS studies. A total of 94% had human papillomavirus (HPV)/p16 positive OPSCC and 74% were T0-T2. Sixty-four patients underwent [C]RT while 33 patients underwent S-[C]RT. After treatment, posterior pharyngeal wall at hold (PPWhold) increased 3.2 standard deviation (SD) between 0 and 6 months (p < 0.001), then decreased 2.2 SD between 6 and 12 months (p < 0.001) and did not return to baseline. Hyoid-to-larynx (HL) (p = 0.046) and maximal hyoid displacement (Hmax) + HL (p = 0.042) increased between 6 and 12 months. Hmax (p = 0.020) and Hmax + HL (p < 0.001) decreased between 12-24 months beyond baseline values. The decrease in HL and increase in PPWhold (p < 0.05) correlated with an increase in PAS. From baseline, increased pharyngeal constriction ratio correlated with decreased FOIS and PPWhold (p < 0.05).

Conclusions: Quantitative swallowing kinematic measures can effectively track changes in swallowing physiology. Increased PPWhold and restricted hyolaryngeal movement were seen in patients with OPSCC after treatment and correlated with a change in swallowing outcome, emphasizing the need for serial VFSS monitoring and targeted intervention.

Level of evidence: 3 Laryngoscope, 133:1339-1348, 2023.