Radiation Therapy of Nasopharyngeal Carcinoma

Nho, Young Ju; Cho, Jeong Gill; Ahn, Seung Do; Choi, Eun Kyung; Kim, Jong Hoon; Kang, One Chul; Chang, Hyesook

Abstract

PURPOSE
This is a retrospective study to evaluate the results of radiation therapy and prognostic factors influencing the results in nasopharyngeal carcinoma.
MATERIALS AND METHODS
From October 1989 to May 1996, 56 patients were treated for nasopharyngeal carcinoma at Department of Radiation Oncology. According to stage, patients were distributed as follows: stage I (2), II (13), III (11), IV (30). Twenty-eight patients were treated with radiation therapy only, 7 patients were treated with neoadjuvant chemotherapy followed by radiation therapy. Twenty-one patients were treated with radiation therapy and weekly CDDP. After external beam radiotherapy of 60Gy, 46 patients received boost dose with intracavitary radiation and 9 patients with 3D conformal therapy. One patient received boost dose with 2 dimensional photon beam therapy. The tumor dose ranged from 69.4Gy to 86.2Gy with median dose of 74.4Gy. The follow-up period ranged from 5 months to 92 months with a median of 34 months.
RESULTS
Forty-seven patients achieved complete response and 8 patients showed partial response. One patient showed minimal response. Patterns of failure were as follows : locoregional recurrence (8) and distant metastasis (18). Among these patients, 2 patients failed locoregionally and distantly. The sites of distant metastasis were bone (8), lung (8) and liver (4). Five years survival rate was 67.2% and 5 years disease-free survival rate was 53.6%. KPS (P=0.005) and response of radiation therapy (P=0.0001) were significant prognostic factors for overall survival. KPS (P=0.02) and response of radiation therapy (P=0.005) were significant prognostic factors for disease-free survival.
CONCLUSION
This retrospective study showed that distant metastasis was the predominant pattern of relapse in nasopharyngeal cancer. Neoadjuvantchemotherapy or weekly CDDP did not influence the distant metastasis-free survival. For advanced T stage, 3D conformal therapy provided an improved dose coverage compared to ICR. But further follow-up was needed in patients with 3D conformal therapy to assess the efficacy of this therapy. Development of techniques of radiation therapy to improve locoregional control and of more effective systemic chemotherapy regimen are needed.