MRI in detection of brain metastases at initial staging of small-cell lung cancer.

We prospectively investigated 40 patients with small-cell carcinoma of the lung (SCLC) for signs of brain metastasis by neurological examination and MRI of the brain, to determine the significance of MRI for staging. MRI could not be completed in one patient, who was excluded from the study. The MRI studies of the remaining patients showed no abnormalities in 12, cerebral infarcts in 2 and brain metastases in 11 patients, of whom 3 no relevant symptoms. Nonenhancing white matter lesions were found in 14 patients. In 3 of the 4 patients with an abnormal neurological examination at diagnosis, nonenhancing white matter lesions later developed into contrast enhancing lesions compatible with brain metastases; in 2, this occurred during the course of the chemotherapy. MRI did not change the clinical staging in patients with asymptomatic brain metastases.