A Result and Prognostic Factors of Hypofractionation Radiation Therapy in Early Glottic Cancer

Korean Journal of Head & Neck Oncology 2005;21(2):132-138.
Published online November 30, 2005.

Mi Jo Lee;Hun Jung Kim;Woo Chul Kim;Jun Gou Loh

초기 성문암 환자에서 소분할조사법의 방사선 치료 결과와 예후 인자

이미조;김헌정;김우철;노준규

Abstract

Purpose
The purpose of this study was to establish general guidelines for the treatment of patients with early glottic cancer(T1-2N0M0), by assessing the role of primary radiation therapy and by analyzing the tumor-related and treatment-related factors that influence treatment results. We also studied the results of hypofractionated radiation therapy for early glottic cancer. Material and Methods: This retrospective study comprised 48 patients who suffered from early glottic cancer and were treated by primary radiotherapy at Inha University Hospital, between May 1997 and October 2004. T-stage distribution showed 38 patients as T1 and 10 patients as stage T2. Thirty-eight patients underwent hypofractionated radiotherapy using a 6 MY photon beam, a total tumor dose of 63Gy, in 5 weekly fractions of 2.25Gy, with an overall radiation treatment time of 38 days. Ten patients in the T2 stage tolerated a total dose of 63-72 Gy(median 68.4Gy) in 5 weekly fractions of 1.8-2.0Gy, with an overall radiation treatment time of 40-87 days(median 51 days). All patients were followed up for at least 3 years. Univariate and multivariate analyses were performed to identify the prognostic factors affecting the treatment results. Result: The 5-year survival rate was 92% for all patients, 94% for T1 patients and 91% for T2 patients. The local control rate was 93.5% for all patients, 95% for T1 and 92.2% for T2 patients. Three patients suffered a relapse following radiotherapy, and underwent subsequent salvage surgery. We included T-stage, tumor location, total radiation dose, field size and overall radiation treatment time as potential prognostic factors. Only T-stage was found to be statistically significant in the univariate analysis, but in the multivariate analysis, it was not found to be significant.
Conclusion
High curative and voice preservation rates were obtained with hypofractionated radiotherapy. Further study with a larger number of patients is needed to determine the prognostic factors affecting treatment results.

Key Words: Early glottic cancer, Hypofractionated radiation therapy, Prognostic factors