- 作者：Yusuke Demizu ; Masao Murakami ; Daisuke Miyawaki ; Yasue Niwa ; Takashi Akagi ; Ryohei Sasaki ; Kazuki Terashima ; Daisaku Suga ; Isao Kamae ; Yoshio Hishikawa
- 刊名：International Journal of Radiation Oncology*Biology*Physics
- 出版年：2009
- 出版时间：1 December 2009
- 年：2009
- 卷：75
- 期：5
- 页码：1487-1492
- 全文大小：376 K
Purpose
To assess the incident rates of vision loss (VL; based on counting fingers or more severe) caused by radiation-induced optic neuropathy (RION) after particle therapy for tumors adjacent to optic nerves (ONs), and to evaluate factors that may contribute to VL.Methods and Materials
From August 2001 to August 2006, 104 patients with head-and-neck or skull-base tumors adjacent to ONs were treated with carbon ion or proton radiotherapy. Among them, 145 ONs of 75 patients were irradiated and followed for greater than 12 months. The incident rate of VL and the prognostic factors for occurrence of VL were evaluated. The late effects of carbon ion and proton beams were compared on the basis of a biologically effective dose at α/β = 3 gray equivalent (GyE3).
Results
Eight patients (11 % ) experienced VL resulting from RION. The onset of VL ranged from 17 to 58 months. The median follow-up was 25 months. No significant difference was observed between the carbon ion and proton beam treatment groups. On univariate analysis, age (>60 years), diabetes mellitus, and maximum dose to the ON (>110 GyE3) were significant, whereas on multivariate analysis only diabetes mellitus was found to be significant for VL.
Conclusions
The time to the onset of VL was highly variable. There was no statistically significant difference between carbon ion and proton beam treatments over the follow-up period. Based on multivariate analysis, diabetes mellitus correlated with the occurrence of VL. A larger study with longer follow-up is warranted.