Preoperative computed tomography of the brain in non-small cell bronchogenic carcinoma

Computed tomography of the brain is the most accurate diagnostic investigation for detecting intracranial tumours. A prospective study was undertaken to try to maximise the cost effectiveness of computed tomography of the brain in the preoperative evaluation of non-small cell lung cancer.

All patients with non-small cell lung cancer who were free of neurological symptoms and were thought to be free of metastases from the results of routine investigations were subjected to computed tomography of the brain in the 12-24 hours immediately before surgery.

Of 158 such patients, five showed positive evidence of metastases, confirmed on craniotomy and excision biopsy; one of these patients was found to have a non-metastatic tumour (false positive). Five patients with a negative scan who underwent lung resection returned within 12 months with neurological defects and positive findings on further computed tomography (false negative). The predominant cell type in patients with positive and false negative scans was adenocarcinoma or adenosquamous carcinoma (7/10); the majority had nodal state N2.

Computed tomography of the brain should be carried out if mediastinal disease is suspected or confirmed in non-small cell lung cancer before proceeding to surgery.