Impact of Dose Received by the Oral Cavity on Patient Reported Outcomes in the Setting of Deescalated Radiotherapy Treatment

Purpose: Xerostomia and dysgeusia are two of the most common and severe

complications for patients undergoing head and neck chemoradiotherapy. HPV positive

patients with oropharyngeal squamous cell carcinoma (OPSCC) have higher survival

rates than HPV negative patients. This research aimed to determine the impact of oral

cavity dosimetry to patient reported toxicity outcomes for 6 and 12 months.

Methods: Multivariate ordinal logistic regress was used to analyze 244 patients who

received deescalated chemoradiotherapy for OPSCC. For each patient both the oral

cavity as a whole and separate substructures of the oral cavity were analyzed to

determine the importance of said structures on xerostomia and dysgeusia.

Results: The results of the analysis showed the oral cavity was a significant predictor of

xerostomia at 6 months post treatment (p=0.0384), however not at 12 months.

Conversely, the oral cavity was not a significant predictor of dysgeusia at 6 months but

was at 12 months (p=0.0092). Additionally, baseline presence of xerostomia was a

predictor at all time points and age was a predictor of dysgeusia at 12 months (p=0.005).

Conclusion: The floor of mouth and oral tongue are the only substructures of the oral

cavity associated with xerostomia and dysgeusia at 6 and 12 months. Our data also

agrees with past studies suggesting the contralateral parotid gland and contralateral

submandibular gland should be spared to limit toxicities at 6 and 12 months.