Surgery, radiation therapy, and chemotherapy for metastatic tumors to the brain

Recent literature has confirmed patient age, Karnofsky status, and the extent of extracerebral tumor as independent prognostic variables in patients with cerebral metastases. In a good-risk population, surgery followed by radiation therapy is superior to radiation alone for treatment of patients with solitary metastases. Stereotactic radiosurgery is feasible in the same select patient population, but questions regarding the extent of delayed toxicity, tumor response, and the impact on quality of life and longevity remain to be answered. Studies of external beam radiation therapy for patients with brain metastases have shown that 1) misonidazole does not improve the response rate, quality of life, or duration of survival, 2) 5 Gy for six fractions and 3 Gy for 10 fractions produce similar results, and 3) reirradiation at doses of 25 Gy for tumors progressing after initial radiation may be feasible in a selected population of patients. Chemotherapy can affect regression of brain metastases in patients with small cell lung and breast carcinoma, as well as melanoma, but the overall contribution to the quality and duration of the patient's life compared with radiation alone is unknown. Intracarotid chemotherapy is feasible for patients with brain metastases, but substantial toxicity precludes its use outside of an investigational setting. Brain metastases remain an important cause of morbidity and mortality for patients with cancer, but the majority of patients still succumb to widespread systemic disease. The goal of treatment of brain metastases should be palliation with minimal infringement upon the patient's quality of life.