Research Paper
Jiwook Lee, Sung Hyun Pa
Abstract
Objective: Stereotactic Radiosurgery for atypical meningiomas was reported with variable degrees of success. Hydroxyurea as radiation sensitizer and salvage chemotherapy was established. We investigated the effect of hydroxyurea after Gamma Knife Radiosurgery (GKS) for atypical meningiomas on tumor control and survival. Materials and methods: Between November 2008 and December 2014, 35 patients with pathological atypical meningiomas were treated by GKS. The medical records were reviewed retrospectively, which included basic epidemiologic characteristics, radiologic features, and clinical courses. Results: Among them, 19 patients with 20 tumors were treated by GKS and followed by adjuvant chemotherapy using hydroxyurea for 1 year or more and were included in this study. They were followed up for 2 years or more after hydroxyurea chemotherapy. Twenty tumors were treated with 26 GKSs. Five tumors had staged treatment. Median volume of tumor was 12.7 cc. Mean prescription dose/session was 14 Gy (10-16 Gy). Patients received hydroxyurea (1000 mg/day) for 1 year after GKS (range 7 to 20 months). Mean follow up duration was 43 months. Tumor control achieved in 18/20 tumors (90%), 15 shrank and 3 stable. Two tumors experienced the progression (14 and 15 months). Transient edema occurred in 6 tumors, but there was no grade 3 or 4 myelosuppression. Distant progression outside the field was observed in 5 patients. In 3 patients, new tumors developed at the edge of craniotomy and in 1 patient, the tumor progression occurred after GKS for another lesion after the adjuvant treatment. Actuarial progression free survival and overall survival at 3 years were 89.5% and 94%. Conclusion: We suggested good tumor control of atypical meningiomas treated with GKS and a year of hydroxyurea. Randomized and double-arm studies are required to confirm the results.