Brain metastasis: an evaluation of the preoperative diagnostic work-up

This is a retrospective study of the evaluation of various preoperative diagnostic tests in locating the primary lesion in 50 patients with a solitary brain lesion seen on computerized tomography and suspected to be metastatic. These patients underwent craniotomy and 54% had primary tumors 40% metastatic tumors and 6.1% non-neoplastic lesions. Of 20 patients with metastasis, the primary was identified in 19 patients with the following locations: 11 pulmonary, 3 breast, 2 thyroid and 2 colon. In 2 patients, no primary was identified. Using simple conditional probability theory, it was established that the probability of a brain metastatic lesion in patients without a previous history of diagnosed non-nervous system cancer, negative chest x-ray, and normal CEA was 14.7%. However, in patients with a previous history of diagnosed non-nervous system cancer, the probability of having a metastatic lesion is high (88%). Extensive testing preoperatively may be justified in these cases because of its value in surgical decision-making and long-term prognosis. (Author)