[Two cases of lung cancer patients with postoperative brain metastases obtaining long-term survival after gamma knife radiosurgery].

We report two cases of lung cancer patients with postoperative solitary brain metastases obtaining long-term survival after gamma knife stereotactic radiosurgery. Both were seventies men and had good performance status without active extracranial disease. In one case, an asymptomatic metastatic brain tumor 1.8 cm in maximum diameter appeared one year and two months after the operation and was irradiated with gamma knife resulting in complete local control for seven years. He is alive with solitary lung metastasis in good performance status. In the other case, gamma knife was employed for a metastatic brain tumor 2.7 cm in maximum diameter that appeared nine months after the operation accompanying incomplete left hemiplegia. Six months later, the tumor was enlarged and gamma knife was repeated, but the tumor growth could not be suppressed. Following deterioration of hemiplegia and appearance of convulsion, he died of neurological disorder three years and two months after the onset of brain metastasis. Gamma knife stereotactic radiosurgery for metastatic brain tumors is less invasive and a repeatable technique, and is expected to provide a good local control and a survival benefit for appropriately selected patients.