Salivary Gland Volume Predicts Malnutrition in Irradiated Head and Neck Cancer Patients: A Prospective Analysis.

Background/aim: Xerostomia following (chemo-) radiotherapy (CRT) is common in head and neck (HNC) patients. This prospective study focused on investigating the link between salivary gland function and the onset of malnutrition in HNC patients.

Patients and methods: Between 2018 and 2020, 61 HNC patients scheduled for curative CRT were prospectively recruited. Nutritional status was assessed by bioelectrical impedance analysis (BIA) and xerostomia was evaluated based on the Common Terminology Criteria for Adverse Events, (CTCAE). Patient-reported outcomes for xerostomia-related symptoms, such as "dry mouth" and "sticky saliva", were also collected. Data were assessed at the beginning of therapy, during treatment, at the end of treatment, and during follow-up. Organs at risk were contoured including the submandibular and parotid glands. Dose-volume parameters were extracted for the mean Dose (D_mean), V15 Gy, V30Gy and V45Gy.

Results: No correlation was found between the dosimetric parameters [D_mean, V15Gy (%), V30Gy (%) and V45Gy (%)] and the occurrence of malnutrition [defined by a fat-free mass index (FFMI) <15 kg/m² (♀) and <17 kg/m² (♂) kg/m² and/or body-mass index (BMI) <18.5 kg/m²] at any of the three time points tested. However, the volume of the parotid glands prior to therapy appeared to be related to the development of malnutrition. This effect was not observed with the submandibular glands. A cumulative parotid gland volume of 55.3 cm³ was identified as the threshold for malnutrition at the second follow-up examination.

Conclusion: Although none of the dosimetric factors were associated with the development of malnutrition, the baseline parotid gland volume emerged as an independent predictor of malnutrition in head and neck cancer patients with xerostomia.