Preoperative Clinical Radioimmunodetection of Pancreatic Cancer by (111)In‐labeled Chimeric Monoclonal Antibody Nd2

The present study was carried out with the purpose of evaluating the clinical usefulness of radioimmunodetection (RAID) with (111)In‐labeled murine/human chimeric monoclonal antibody, Nd2 (c‐Nd2) in patients with pancreatic cancer. Nineteen patients suspected to have pancreatic cancer were administered intravenously 74 MBq/2 mg (111)In‐labeled c‐Nd2 in 100 ml of saline containing 2% albumin over 30 min. A scintigram was obtained on the 3rd day after infusion by using single photon emission computed tomography (SPECT) imaging. Of the 14 patients finally diagnosed as having pancreatic cancer on the basis of surgical specimens or progress of disease, specific focal uptake at the site of the tumor was detected in 12 (true positive cases), representing a sensitivity of 85.7% (12/14), and liver metastasis was found in one case with metastasis. Of the 5 patients diagnosed with tumor‐forming pancreatitis (TFP), 4 patients demonstrated true negative imaging, but one patient whose tumor demonstrated interesting findings in histology and immunostaining, showed false positive imaging. Of patients investigated for human anti‐chimeric antibody (HACA) response, none showed HACA response, and no allergic reaction was seen in any of the patients administered c‐Nd2. These results suggest that RAID with (111)In‐labeled c‐Nd2 is useful for differential preoperative diagnosis between invasive pancreatic cancer and TFP.