Evaluation of Xerostomia Following 3 Dimensional Conformal Radiotherapy for Nasopharyngeal Cancer Patients

Park, Young Je; Ahn, Yong Chan; Park, Won; Ju, Sang Gyu; Nam, Heerim; Oh, Dongryul; Park, Hee Chul

Abstract

PURPOSE: This study is to evaluate the xerostomia following 3-dimensional conformal radiation therapy (3D CRT) in nasopharynx cancer patients using the xerostomia questionnaire score (XQS).
MATERIALS AND METHODS
Questionnaire study was done on 51 patients with nasopharynx cancer who received 3D CRT from Dec. 2000 to Aug. 2005. 3D CRT technique is based on "serial shrinking field" concept by 3 times of computed tomography (CT) simulation. Total target dose to the primary tumor was 72 Gy with 1.8 Gy daily fractions. Xerostomia was assessed with 4-questions XQS, and the associations between XQS and time elapsed after RT, age, sex, stage, concurrent chemotherapy, and parotid dose were analyzed.
RESULTS
Concurrent chemotherapy was given to 40 patients and RT alone was given to 11 patients. The median time elapsed after 3D CRT was 20 (1~58) months and the mean XQS of all 51 patients was 8.4+/-1.9 (6~14). XQS continuously and significantly decreased over time after 3D CRT (x(2)=-0.484, p<0.05). There was no significant difference in XQS according to sex, age, and stag. However, XQS of concurrent chemotherapy patients was significantly higher than RT alone patients (p=0.001). XQS of patients receiving total mean parotid dose > or=35 Gy was significantly higher than <35 Gy (p=0.05).
CONCLUSION
Decreasing tendency of XQS over time after 3D CRT was observed. Concurrent chemotherapy and total mean parotid dose > or=35 Gy were suggested to adversely affect radiation-induced xerostomia.