The First Prognostic Tool to Estimate the Risk of Late Grade ≥3 Xerostomia in Patients Irradiated for Head-and-Neck Cancer

Background/Aim: Xerostomia is a serious complication following radiotherapy of head-and-neck cancers. A prognostic tool was developed for estimating its risk. Patients and Methods: In our previous study, age, tumor site, bilateral lymph node involvement, definitive radiotherapy, and addition of systemic therapies showed significant associations with grade ≥3 late xerostomia or trends. In additional analyses, mean radiation dose to ipsilateral parotid gland was significant (p=0.011). These six factors were included in the prognostic tool. Scoring points of 0 (lower risk) or 1 (higher risk) were assigned to each factor and added for each patient. Results: Patient scores ranged between 0 and 6; Grade ≥3 xerostomia rates were 0%, 8%, 24%, 26%, 25%, 42%, and 100%, respectively. Three groups were designed (0-1, 2-4, and 5-6 points) with grade ≥3 xerostomia rates of 5%, 25%, and 50%, respectively (p<0.001). Conclusion: This new tool helps estimating the risk of radiation-induced grade ≥3 xerostomia. It can support physicians and other medical staff members during treatment planning.