Pineal region tumors: the role of stereotactic radiosurgery

Between July 1992 and August 1995, 11 patients with pineal region tumors (PRTs) were treated at our center. Ages ranged from 8 to 72 years (median 21). Diagnosis was confirmed by histological examination in 7 patients. The remaining cases had strong neuroradiological and marker evidence of the diagnosis, so that a stereotactic biopsy could be avoided. The pathological diagnoses were pinealocytoma (n = 1), tectal astrocytoma (n = 1), germinoma (n = 2), pinealoblastoma (n = 2), and meningioma (n = 3). The marginal dose of these tumors ranged from 12 to 18-20 Gy. Conventional external radiotherapy was never used in this series. With a median follow-up of 12.3 months (range 2-34), all tumors responded to treatment and disappeared or ceased growing. We observed no mortality or major morbidity. One patient (tectal astrocytoma) had a mild radiation-induced reaction, with headache and transient worsening of an abducent nerve palsy, which were controlled with steroids. In germinomas and pinealoblastomas, recovery of normal cerebrospinal fluid circulation was observed in less than 7 days, in parallel with major tumor shrinkage. In this study we confirm that radiosurgery can be an effective and safe alternative for the treatment of pinealocytomas and low-grade tectal gliomas. Moreover, we consider that the characteristics of the radiosurgery technique suggest the method should be evaluated for the treatment of malignant PRTs.