To determine whether tumors containing carcinoembryonic antigen could be detected by administration of a radiolabeled, affinity-purified, goat lgG having 70 per cent immunoreactivity against carcinoembryonic antigen, 18 patients with a history of cancer of diverse histopathology received an average total dose of 1.0 mCi of 131l-labeled lgG. Total-body photoscans were performed with a gamma scintillation camera at various intervals after administration of the radioactive antibody. Ordinary photoscans proved difficult to interpret because of blood-pool background radioactivity, thus necessitating the computer subtraction of radioactive blood-pool agents from the antibody's 131l activity. Tumor location could be demonstrated at 48 hours after injection in almost all cases studied. The scans were negative in patients without demonstrable tumors or with tumors apparently devoid of carcinoembryonic antigen. Circulating antigen levels of up to 350 ng per milliliter did not prevent successful tumor imaging after injection of the radioantibody.

No abstract

No abstract

No abstract

No abstract

evidence of embolism by angiography. It is concluded firstly that lung scanning is a sensitive screening procedure for pulmonary embolism and, secondly, that segmental perfusion defects are highly suggestive of pulmonary embolism.

This study reports the use of radiolabeled antibodies to alpha-fetoprotein for the detection and localization of hepatocellular and germ cell carcinomas. Twelve patients with histories of histologically-confirmed neoplasia received a total dose between 1.0 and 4.4 mCi of 131I-labeled goat IgG prepared against human alpha-fetoprotein. Total-body photoscans were taken with a gamma scintillation camera at various intervals after injection of the radioactive antibody. Computer subtraction of radioactive technetium background images from the antibody 131I scans permitted the visualization of all tumor sites known to be present in 4 patients with either primary hepatocellular cancer or metastatic germ cell carcinoma of the testis. In contrast to the results with the specific antibody, radioactive normal goat IgG given to one of these patients with metastatic embryonal carcinoma of the testis failed to show equivalent localization. Among 8 patients with diverse neoplasms not believed to contain alpha-fetoprotein, 5 of 19 tumor sites showed radioactive antibody accretion, although significantly less than in the patients with liver or testicular cancer. Circulating antigen levels of up to 15,000 ng per milliliter did not prevent successful tumor imaging after intravenous injection of the radioantibody. This investigation indicates that alpha-fetoprotein-containing tumors can be detected and localized in vivo by the method of radioimmunodetection.

A prospective double-blind comparison of 99mTc-hydroxymethane diphosphonate (HMDP) and 99mTc-methylene diphosphonate (MDP) as bone-seeking agents was performed with 102 patients. Densitometry showed that both cancellous/compact bone and cancellous bone/soft-tissue ratios were greater with HMDP (p less than 0.05); compact bone/soft-tissue and bone lesion/normal bone ratios were the same with both agents. Bone delineation, soft-tissue uptake, and overall image quality were the same with both agents. The HMDP formulation contained 78% fewer stannous ions and had a longer useful life after technetium labeling than MDP.