Principles of treatment of the pineal region tumors.

BACKGROUND: A pineal region tumor is an uncommon deep-seated, heterogeneous group of mass lesions of the brain, and the management strategy of any types of these tumors remains controversial. It is the purpose of this communication to present results of our experience in treating patients with these neoplasms.

METHODS: From 1976 to 1999 about 700 patients with tumors of the pineal region and posterior third ventricle were managed at the Burdenko Neurosurgery Institute. In more than 330 cases the tumor was removed. In this paper we present results of 287 patients with histologically verified pineal region tumors for the period from 1976 to 1999. All of them had verified tumor histology, excluding only five cases in which stereotactic biopsy procedures were uninformative. There are four main groups of tumors: the germ cell tumors-87 (31%); the pineal parenchymal tumors-75 (27%); the glial tumors-77 (27%); and miscellaneous-43 (15%). There were 255 surgical procedures for tumor removal performed in 244 and stereotactically guided biopsies in 61 patients, 168 (58%) with obstructive hydrocephalus who underwent cerebrospinal fluid shunting. Radiation therapy was administered in 145 (51%) and chemotherapy in 16 patients. Follow-up data were collected in 209 cases (80%). Survival was calculated with the Kaplan-Meier product limit method.

RESULTS: The occipital transtentorial and infratentorial supracerebellar approaches were the most commonly used on our series-138 (54%) and 87 (34%), respectively. In the remaining cases, subchoroidal approach, approach through the fourth ventricle, and the combined approaches were used. A total tumor removal was achieved in 148 operations (58%), subtotal in 74 (29%) and partial in 33 (13%). The projected 5-year and 10-year survival rates for patients with malignant pineal tumors, who received irradiation after tumor resection or underwent radiation therapy alone, were: 95% and 88% for pure germinomas, 80% and 50% for high grade gliomas, 44% and 0% for malignant pineal parenchymal tumors, and 20% and 0% for malignant germ cell tumors, respectively.

CONCLUSIONS: Benign pineal tumors should be cured with surgery alone. Malignant tumors should be treated with aggressive resection followed with irradiation and chemotherapy. Pure germinomas, which are exquisitely radiosensitive, can be cured by conventional radiation therapy alone.