Imaging lung cancer with radiolabeled antibodies.

Radiolabeled antibodies have been studied by several investigators as to their potential role in the diagnosis and staging of lung cancer. Studies with indium-111-labeled antibodies in limited numbers of patients have shown that 75% to 100% of primary lung tumors can be delineated and that the detection of metastases is dependent on size and location. Hepatic metastases and lesions smaller than 2 cm frequently are not visualized. Other studies with a technetium-99m-labeled Fab fragment of NR-LU-10 have been carried out for the staging of small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). In a large, well controlled multicenter study of patients with SCLC, staging by antibody imaging alone was as accurate as a combination of the conventional staging tests, and the positive predictive value for antibody staging of extensive disease was greater than 95%. In patients with NSCLC, antibody imaging was comparable to computed tomography for staging the mediastinum and was able to identify distant metastases at the same time.