Experience with hypofractionated stereotactic radiosurgery in a series of patients with skull base tumors

Introduction and objective Although the effectiveness of single-fraction brain stereotactic radiosurgery has been extensively demonstrated, recent evidence is suggesting that when skull base lesions are the targets, radiation near critical structures (e.g., optic nerves, and brainstem) should be reduced to avoid radiotoxic effects, with the risk of treatment inefficacy. Hence, in these tumors, hypofractionated stereotactic radiosurgery (HSRS) would offer a therapeutical opportunity. Here, we present our experience with this modality in the management of patients with skull base tumors. Methods A series of patients with skull base tumors was retrospectively analyzed to evaluate the treatment with HSRS. The primary endpoint was tumor control in post-treatment imaging. Age, sex, tumor histology, tumor volume, type of radiation protocol, pre-treatment Karnofsky performance status (KPS), previous neurosurgery, and prior radiotherapy were analyzed. Results A total of 84 patients were treated between January/2009 to January/2017. Median age: 51.5 years. Female gender: 53.6%. There was 92.7% of non-progression after HSRS, with a median f/u of 36 months. Main tumors treated were pituitary adenomas, acoustic schwannomas, and skull base meningioma. Most of the patients were treated with a 5-day fraction scheme of a 25 Gy total dose. No late radiotoxicity was observed. In multivariate analysis, a high KPS was associated with non-progression. Conclusions In our series of patients, the high incidence of non-progression of tumors indicated that HSRS could be a therapeutic option in some cases of skull base lesions, mainly residuals or tumoral recurrences of pituitary adenomas, schwannomas, and meningiomas.