Object. The aim of this study was to document the possible role of Gamma Knife radiosurgery, suitable for the treatment of deep
and well limited tumors, in the management of pineal parenchymal tumors (PPT).
Population and methods. We reviewed retrospectively a series of 13 patients with PPT treated by Gamma Knife radiosurgery during 16 procedures. Mean
age was 31 (range 10 to 74). Eight patients had pineocytomas (61.5%), and 5 had pineoblastomas (38.5%). Radiosurgery was performed
alone in 6 cases, after partial microsurgical resection in 3 cases, in association with chemotherapy in 3 cases and following
conventional fractionated radiotherapy in 1 case. The marginal dose to these tumors ranged from 11 to 20 Gy (mean 15 Gy).
Results. With a mean follow-up of 34 months (range 6 to 88), all tumors responded to treatment and disappeared or ceased growing.
Two patients with pineoblastoma had tumor size progression out of the initial target requiring several radiosurgery procedures.
At the end of the follow-up period, 10 out of 12 patients were alive. Two patients with pineoblastoma died because of carcinomatous
meningitis or tumor size progression. We observed no mortality or major morbidity related to radiosurgery.
Conclusion. This study confirms that radiosurgery can be an effective and safe primary treatment modality for patients with pineocytomas.
It should have a role in multimodality therapy which includes microsurgical resection, fractionated radiotherapy and chemotherapy
for the management of malignant pineal tumors.
Keywords: Gamma Knife radiosurgery; pineal region tumors; pineal parenchymal tumors; stereotactic biopsy; pineocytoma; pineoblastoma.