Long-Term Outcomes of Stereotactic Radiosurgery for Pineocytomas: An International Multicenter Study

Pineocytomas are grade 1 tumors arising from the pineal parenchyma. Gross total resection can potentially cure these benign lesions but can be associated with morbidity. This study was designed to provide multi-institutional data to evaluate the results of stereotactic radiosurgery (SRS) for pineocytomas.

Centers participating in the International Radiosurgery Research Foundation were asked to review their database and provide data for patients who had SRS for histology confirmed grade 1 pineocytomas, for whom clinical and imaging follow-up of at least 6 months was available.

In total, 38 patients underwent SRS as part of the management of a pineocytoma. The median age at SRS was 39 years (range 8-76). SRS was performed as primary approach in 68%, adjuvant after partial resection 19%, and at recurrence in 13% of patients. The median margin dose was 15 Gy (range 11-25 Gy). The median treatment volume was 3.35 cc (range 0.1-17.9 cc). Local tumor control was achieved in 92% of patients, with a mean actuarial progression-free survival of 21.6 years (median not reached). At last follow-up, 82% were still controlled, 8% had local recurrence, and 10% had cerebrospinal fluid dissemination. Tumor control was significantly better when SRS was used as primary care compared with the adjuvant or recurrent setting ( P = .016). Five patients (13%) died during follow-up, all from tumor progression. The actuarial mean survival duration was 24.3 years, with a 5-year survival rate of 91%, and an estimated rate of 76% at 29 years. Larger tumor volume at SRS was found to be correlated to increased risk of death ( P = .045). Transient symptomatic adverse radiation effects were observed in 4 patients (11%).

SRS appears safe and effective for the management of pineocytomas. Long-term tumor control is achieved in most cases. SRS can be offered to selected patients as an alternative to surgical resection.