THE ESTIMATION OF LATE RADIATION REACTION OF SALIVARY GLANDS IN PATIENTS WITH SQUAMOUS CELL CANCER IRRADIATED IN HEAD&NECK REGION – THE PROSPECTIVE STUDY

Purpose: The purpose of this study is to estimate the late radiation toxicity of salivary glands in patients with squamous cell cancer irradiated by conventional (3D CRT) or accelerated method (CAIR or CB).The special goal there is to analyse the influence of method of contouring the glands on the values of accumulated doses. Materials: In 65 patients with pharyngeal and laryngeal cancer irradiated to total dose in range 62.5-72,O Gy the estimation of late radiation toxicity of salivary glands was provided. All patients were irradiated by conventional (3D CRT) or accelerated method (CAIR or CB). There were used two methods of contouring parotids: whole organs and whole parotids including superficial part. The late radiation reaction was estimated after 3, 6 and every 6 months after final treatment with using CTC version 3.0 classification. The non parametric Mann-Whitney and Spearman test was used for the estimation of relationships. Results: We have observed the middle level of xerostomia connecting with change of amount and consistency of saliva after irradiation. The contouring of whole parotids including superficial part of organ had significant influence on decrease of mean, median and modal doses in whole organs. In our material we had: mean doses=29,93 Gy, median doses=29,18 Gy and modal doses =28,85 for whole parotids. Conclusions: Xerostomy is the most troublesome symptom in patients with squamous cell cancer in H&N region. The contouring of whole parotids including superficial part had significant influence on decrease of mean, median and modal doses in whole organ in the correlation to the group of patients with contouring only whole parotids.This prospective study is being continued.