Purpose: To investigate if salivary function can be spared using submandibular gland (SMG) transfer in head-and-neck (HN) cancer patients with unilateral disease.
Methods: SMG transfer was performed for 10 HN patients treated with radiation therapy (RT). Seven matching controls have been enrolled. Mean doses to SMG and parotid glands were extracted from treatment plans. Stimulated and unstimulated salivary flow, quality of life data using xerostomia XeQoLS questionnaire and eating assessment tool, EAT-10, were collected pre-RT, and at 3, 6 and 12 months.
Results: Mean doses to spared and non-spared parotid glands from treatment plans were very similar, 18.2±4.5 and 29.2±8.1Gy among transfer patient; 17.4±6.0 and 31.3±11.3Gy among controls. Doses to non-spared SMG were 68.8±2.6 and 68.8±4.7Gy. Significant reduction of mean dose to the transferred SMG was achieved in planning, 17.9±4.8Gy vs 50.3±18.2, p<0.01. Overall recovery of both stimulated and unstimulated salivary flow was observed, albeit with significant patient-to-patient variation. Relative to pre-RT stimulated flow at 3 and 6 months was 68.4±50.7 and 79.8±19.5% among SMG transfer patients; 50.7±9.8 and 60.8±32.7% among controls, the difference was not significant. Xerostomia and eating assessment scores also indicated improved QoL among patients receiving SMG transfer, XeQoLS score 12.7±8.4, 8.7±6.9 and 8.8±7.1 at 3, 6 and 12 months compared to 20.3±18.4, 12.0±12.7 and 5.5±0.7 among controls with a similar trend for EAT-10 scores. None of the differences were statistically significant. Notably, two SMG transfer patients who showed slow salivary flow recovery also showed significant increase in mean dose to the spared based on CBCT analysis, from <20Gy to >30Gy.
Conclusion: Persistent but not statistically significant improvement in salivary flow and QoL was seen in patients receiving SMG transfer vs controls. A subset of SMG transfer patients showed significant increase in mean dose to spared SMG attributable to head tilt/lower jaw position.
Not Applicable / None Entered.