3D radiotherapy in the parotid gland and its dosimetric relationship with salivary flow and quality of life in patients with head and neck cancer

Aim: Hyposalivation and dry mouth affect the quality of life in patients with Head and Neck Cancer, who did the treatment with radiotherapy. Thus this study has the objective to evaluate the dosimetric relationship between 3D radiotherapy and changes in salivary flow, xerostomia and quality of life in patients with head and neck cancer according to the volume of the irradiated parotid gland. Methods: 23 patients with cancer in the head and neck area and in need of 3D radiotherapy were followed up during radiotherapy treatment, and the parotid gland (PG) design was also performed in radiotherapy planning. Questionnaires were carried out to determine xerostomia and quality of life, while the salivary flow was determined through calculations regarding the collection and weighing of saliva. Such data were collected in three moments: before the beginning of the radiotherapy treatment (D0), in the middle of the treatment (D1) and at the end of it (D2). The numerical variables are represented by measures of central tendency and measures of dispersion. Results: when associating the salivary flow, the xerostomia questionnaire and the OHIP-14, a statistically significant difference was found (p-value <0.001), as well as when comparing some volumes of irradiated PG with the OHIP-14. However, no relationship was found between dosimetric data, xerostomia and hyposalivation. Conclusion: patients undergoing 3D radiotherapy for malignant neoplasms in the head and neck region had decreased salivary flow, increased complaints of dry mouth and decreased quality of life. However, it was not possible to establish a statistically significant correlation between these findings and the volumes of irradiated parotids.