Room: AAPM ePoster Library
Purpose: Patient xerostomia and dysgeusia are the two most frequent and severe toxicities reported by patients receiving de-intensified chemoradiotherapy (DCRT). We sought to determine the impact of oral cavity dosimetry (per region and treated as a single structure) to patient reported xerostomia and dysgeusia at 6 and 12 months post DCRT.
Methods: We analyzed 244 prospectively accrued patients treated with DCRT for HPV-associated oropharyngeal cancer. Each patient had their oral tongue, base of tongue, floor of mouth, cheeks, lips, hard palate, and soft palate contoured alongside all salivary glands. Patient reported outcomes (PRO) were acquired at 6 and 12 months post-treatment. Multivariate ordinal logistic analyses were conducted to assess the importance of the oral cavity (and each region) for patient reported xerostomia (PRX) and dysgeusia (PRD) at 6 and 12 months post DCRT. A stepwise AIC was used to determine optimal models.
Results: Mean dose to the oral cavity was significant for PRD at 12 months but not at 6 months (p = 0.01). The mean dose to the oral tongue (p = 0.04) and patient age (p = 0.005) were significant for PRD at 12 months. The mean oral cavity dose was significant for PRX at 6 months but not at 12 months compared to patients’ salivary glands. Baseline xerostomia (none vs. any) was significant at both time points. Mean dose to the floor of mouth, contralateral parotid, and baseline xerostomia were significant at 6 months for PRX and the mean dose to the contralateral submandibular gland and baseline xerostomia were significant for PRX at 12 months.
Conclusions: Our data suggests that only oral tongue and floor of mouth associate with analyzed toxicities at 6 and 12 months. Physician (or data driven) weighting between importance of dry mouth vs. taste changes would allow for plans to optimized for PRO.