Cell kinetic investigations in brain tumors studied by serial stereotactic biopsy.

Between July 1983 and July 1986, 109 consecutive patients affected by brain tumors and selected for stereotactic biopsy underwent in vitro investigation of cell kinetics. The potential proliferative activity of these different neoplasms, evaluated as in vitro 3H-thymidine labeling index (LI), has been determined in 46 mature astrocytomas, 19 anaplasic astrocytomas, 25 glioblastomas, 5 cystic craniopharyngiomas, 6 metastatic tumors, 4 primary C.N.S. lymphomas, 3 pineal germinomas and one choroid plexus papilloma. The relevance of LI on prognosis has been evaluated in 35 patients affected by glial tumors with adequate follow-up longer than 2 years. This retrospective study allowed us to demonstrate the prognostic value of LI in mature astrocytoma and anaplasic astrocytoma series. The feasibility of LI determination by in vitro procedure has been demonstrated also in non-neuroectodermal tumors. In craniopharyngioma the LI investigations allowed to demonstrate a peculiar topographic arrangement of cells in S phase.