Radioimmunodetection of colorectal carcinoma with 111In-labelled monoclonal antibody IVP ZCE 025 (a tissue culture-produced anti-CEA MAb).

The aims of this prospective, nonrandomized phase I/II study were to evaluate (1) the safety and (2) the detection rate of tissue culture-derived, 111In-labelled anti-CEA monoclonal antibody IVP ZCE 025 in patients with primary, metastatic and occult colorectal carcinomas. 111In-IVP ZCE 025 imaging correctly identified 31 of 37 primary colorectal carcinomas, 10 of 19 hot liver metastases, 11 of 16 distant metastases and seven of seven local tumour recurrences. Previously unsuspected tumours were detected by IVP ZCE 025 imaging in 11 of 34 patients. The scans were also true negative in four patients. The overall performance characteristics of IVP ZCE 025 at monoclonal antibody doses of 1.0-5.0 mg were comparable to those obtained with 40.0 mg ascites-produced ZCE 025. No clinical or biochemical adverse reactions were encountered in the 61 patients entered into this study.

Colorectal carcinoma metastases: detection with In-111-labeled monoclonal antibody CCR 086.

A phase I/II clinical trial with indium-111-labeled antimucin murine monoclonal antibody (MoAb) CCR 086 was conducted. Seventeen patients with histologically proved colorectal carcinoma and known metastatic disease underwent external scintigraphy after administration of 5.5 mCi (203.5 MBq) of In-111 CCR 086 at doses of 5 and 20 mg. Of 25 known lesions, 17 were detected (sensitivity, 68%). The smallest detected lesion in the lung was 1 cm and in the liver was 1.5 cm. The serum half-life of In-111-labeled CCR 086 MoAb was approximately 64 hours. The formation of human antimouse antibody (HAMA) was detected in the serum of four of five patients who received 20 mg of MoAb. No HAMAs were detected in four patients receiving 5 mg of MoAb. No side effects were encountered. Because of effective detection of liver and lung metastases with lower doses (5-20 mg) of CCR 086 conjugated with In-111, further investigations are warranted to assess clinical and therapeutic potentials of CCR 086 in the management of colorectal cancer.

Uptake of myocardial imaging agents by rejecting and nonrejecting cardiac transplants. A comparative clinical study of thallium-201, technetium-99m, and gallium-67.

To study the scintigraphic detectability of cardiac rejection, we performed 135 planar myocardial scans ([99mTc]pyrophosphate, 85; 201Tl, 36; 67Ga, 14) together with endomyocardial biopsies in ten patients for a (mean) 17-mo postoperative period. Specificity of each agent exceeded 89%. Technetium-99m pyrophosphate showed results that significantly correlated with the severity of rejection (p = 0.03), as shown by biopsy, but neither 201Tl nor 67Ga did so (p = 0.63 and 0.81, respectively). Technetium-99m pyrophosphate showed better diagnostic accuracy (85%) than 201Tl (69%) and 67Ga (64%). Technetium-99m pyrophosphate also showed higher negative predictive value (91%) than thallium (76%) and gallium (69%). Thus, a normal 99mTc pyrophosphate scan was usually associated with absence of cardiac rejection. However, all three agents showed unacceptably poor sensitivity (0% to 30%) and thus were not useful as a screening test for cardiac rejection, even when the same agent was used serially in imaging a given patient.