Clinical Evaluation of Silent Brain Metastasis in Lung Cancer Patients

In 360 lung cancer patients with no brain symptoms, CT scan of the brain was performed for the classification of M-factor. Silent (asymptomatic) brain metastasis was found in 10 cases (2.8%) out of 360 cases. The histologic types of primary lung cancer with brain metastasis were 4 cases of small cell carcinoma, 3 of adenocarcinoma, and 3 of squamous cell carcinoma. All metastatic lesions were solitary. They ranged from 1.0 to 4.5 cm in diameter, and perifocal edema was found in 4 cases. Six of the 10 cases were treated with whole brain irradiation and systemic chemotherapy. Five of the 6 cases revealed a partial response (PR) to treatment. The mean survival time of PR cases was 12.9 months, and 3 of them returned to home life. In conclusion, detection of silent brain metastasis is very important for proper treatment and to improve the quality of life.