The Long-Term Outcome of Cyberknife Radiotherapy for Central Skull Base Meningiomas: A Single-Center Experience

Abstract

Few reports exist demonstrating the effects of CyberKnife radiotherapy (CKRT) on the central skull base meningiomas (CSMs). Retrospective analysis of 113 patients were performed. The median age was 62 (IQR 50 – 72) years old, and 78 patients (69%) were female. Upfront CKRT was performed in 41 (36%), where 17 (15%) patients were asymptomatic. The other CKRT was for postoperative adjuvant therapy in 32 (28%), and for the recurrent or relapsed tumors in 40 (35%) patients. Previous operation was done in 74 patients (66%). Among the available pathology in 46 patients, 37 (80%) were WHO grade I, 8 (17%) were grade II, and 1 (2%) were grade III. The median prescribed dose covered 95% of the planning target volume was 2500 (IQR 2100 – 2500) cGy and the median target volume was 9.5 (IQR 3.9 – 16.9) cm3. The median PFS was 48 (IQR 23 – 73) months and 84% and 78% were free of tumor progression at five, and 10 years respectively. The median follow-up was 49 (IQR 28 – 83) months. PFS was better in grade I than grade II (p = 0.02). No other baseline factors including the history of previous operation was associated with PD or PFS. Adverse events of radiation therapy were radiation- induced optic neuropathy (0.9%), and cerebral edema (4.4%). Asymptomatic cavernous carotid stenosis was found in three (2.7%), five (4.4%) underwent ventriculoperitoneal shunt placement for normal pressure hydrocephalus, and five (4.4%) died. CKRT is useful for the management of CSMs with low rate of adverse events.