ANALYSIS OF THE PROLIFERATIVE POTENTIAL OF RESIDUAL TUMOR AFTER RADIOSURGERY FOR INTRAPARENCHYMAL BRAIN METASTASES

retrospective immunohistochemical study of radiosurgically treated bra in metastases was performed to determine whether residual tumor has re duced proliferative potential. The monoclonal antibodies MIB-10 and PC -10 were used as markers for proliferation. The experimental group con sisted of pathological specimens obtained from five patients in whom b rain metastasis previously had been treated with radiosurgery. Patholo gical specimens obtained from 10 patients with brain metastases, match ed in histology to diseases in the experimental group but untreated by radiosurgery, served as controls. A significant decrease in prolifera tive indices was observed in metastatic brain cancers after radiosurge ry (p < 0.001). These results indicate that the persistent tumor that is present at the site of a metastasis previously treated with radiosu rgery is less viable and may not in itself be a significant finding.