Long-Term Results of stereotactic Brachytherapy (Temporary 125Iodine Seeds) for the Treatment of Low-Grade Astrocytoma (Grade II)

Background: Treatment of low-grade astrocytoma (WHO grade II) (LGA II) remains a challenge. There is limited information regarding the long-term effects of stereotactic brachytherapy (SBT) (temporary 125Iodine seeds) on patients with LGA II. Objectives: The purpose of this study was to evaluate disease control and survival after stereotactic brachytherapy in patients with circumscribed and relatively small size tumors. Materials and Methods: A retrospective review of 29 patients, treated between 1991 and 2011, was conducted to evaluate survival, complications, and local disease control after stereotactic brachytherapy. They belonged to a larger group of 48 cases with low-grade gliomas, treated with stereotactic brachytherapy. The demographic and clinical characteristics in patients including age, sex, and survival time were extracted from records. Results: Thirteen patients were male and 16 were female, with the median age of 29 years (range, 2.5 - 64 years). The median follow-up was 95 (range, 6 - 240) months. Based on Pignatti classification, 10 patients were at low- and 19 patients at high-risk. The median overall as well as progression-free survivals for patients were 135 months (95% confidence interval: 76 - 194) and 96 months (95% confidence interval: 1 - 199), respectively. Five- and 10-year progression-free survivals were 41.4 % and 34.5 %, respectively, and the 5- and 10-year overall survivals were 65.5 % and 44.8%, respectively. Progression-free survival was not significantly higher in smaller size tumors (P = 0.224), nor for spherical versus non-spherical tumors (P = 0.307). There was no treatment-related morbidity after stereotactic brachytherapy, and no radiogenic complications occurred during the follow-up period. Mortality due to tumor progression occurred in 4 patients (14%), and 11 patients were alive at the last follow-up. Conclusions: The stereotactic brachytherapy for patients with circumscribed and relatively small size tumors appears to be a safe, feasible, and minimally-invasive treatment.