Evaluation of salivary hypofunction and oral complication after radiotherapy in patients with malignant neoplasms of head and neck

Introduction. In patients with head and neck malignant neoplasms salivary glands are affected by the radiation therapy because they are located close to the place that is exposed to the total dose of radiation. Therefore, xerostomia and dysphagia are the most frequent post-radiation complications that affect the life of these patients. The volumetric modulated radiation therapy enables higher doses of radiation to be focused on the targeted place, and the surrounding healthy tissues to be exposed to the harmful effect of radiation as less as possible.
Method. This study was conducted by cooperation of the University Clinic for Radiotherapy and Oncology and University Clinic of Maxillofacial Surgery-Skopje. The study sample consisted of 30 patients treated with one of the radiation techniques: 3DCRT and VMAT. The stimulated salivary flow from parotid glands was defined using modified Lashley cups. Post-radiation xerostomia and mucositis were noted in grades based
on the clinical examination, and the rest of the post-radiation complications during the first control after the radiation therapy were registered if they appeared. The moisture of oral cavity was evaluated by the modified Schirmer method.
Results. The comparison of patients treated with one of the radiation techniques showed significantly larger amount of produced stimulated saliva
(ml/min) in patients treated with VMAT compared to those treated with3DCRT (p=0,0054). An insignificant linear negative correlation was found
between the volume of stimulated salivary flow (ml/min) and the localization of the malignant neoplasm-salivary flow was insignificantly decreased in patients with malignant neoplasm of the nasopharynx, oropharynx, hypopharynx and larynx (R(30)=-0,151; p=0,4602). The mucositis appearance was significantly associated with the use of 3DCRT method. The low grade of xerostomia was significantly associated with the use of VMAT method.
Conclusion. The use of the new technique, volumetric modulated radiation therapy, enables to spare the salivary function that is proved by the increased salivary flow, the decreased level of xerostomia and the decreased representation of all other post-radiation complications.
Keywords: hyposalivation, xerostomia, malignant neoplasm of head and neck, volumetric modulated radiation therapy, irradiation consequences