Gamma Knife Radiosurgery of Brain Metastasis from Malignant Pleural Mesothelioma – Report of Three Cases with Autopsy Study in a Case –

The median survival time of malignant pleural mesothelioma (MPM) has been 9 months. Given the short survival, there have been only few cases in which brain metastases have been diagnosed and treated before death. Three cases of brain metastases treated by gamma knife radiosurgery (GKR) are reported. Case I showed a metastatic lesion in the right frontal lobe which was treated by GKR two years after diagnosis of MPM. The lesion markedly reduced and the symptoms were improved, But the patient died of progression of pleural tumor four months after GKR. A year and three months after the diagnosis, asymptomatic bifrontal lesions were treated with GKR. However, Case 2 died of abdominal mass a month after. Case 3 showed headache one and half year after the diagnosis. Three brain lesions were treated by GKR, which disappeared in 4 months. The patient died of new multiple brain metastases and periventricular dissemination seven months after. The autopsy revealed a MPM occupying the left pleural cavity. No neoplastic lesion was found in gamma knife-treated sites. The cause of death was the mass effect by new metastatic lesions. GKR was found effective also for the treatment of brain metastasis of MPM.