[en] Serum prostatic acid phosphates (PAP) immunoassay is used to evaluate patients with prostatic carcinoma; however, as with other tumor markers, the enzyme levels do not necessarily reflect the presence or extent of tumor. The authors investigated the use of radiolabeled PAP antibodies for the in vivo detection of prostatic carcinoma by external scintillation imaging. Nine patients with prostatic carcinoma were entered into the study. Each received from 2.0 to 2.5 mCi of I-131 labeled antibody to PAP, administered i.v. The immunogen (PAP) was purified from normal human seminal fluid. Antiserum was prepared in rabbits by injecting the purified PAP. The antibodies were labeled with I-131 by chloramine-T method (10 to 20 Ci/g of IgG). Total body images were obtained at 24 and 48 hrs following administration of the labeled antibody. Nontarget I-131 activity was diminished by computer processing. Tumor sites detected by I-131 antibodies were correlated with other diagnostic procedures. In 7 of 9 patients primary and metastatic sites of cancer were detected by antibody imaging, however, no bone lesions were detected (6 cases). In 3 patients with concomitant pulmonary tumors, one was identified as of prostate origin. The serum PAP was normal in 4 patients; however, the primary tumor was identified in 3 of these. These findings suggest that the localization of prostatic carcinoma by means of in-vivo imaging of labeled antibodies to PAP is feasible and offers diagnostic opportunities based upon the functional characteristics

[en] To evaluate gastric emptying, 20 patients with anorexia nervosa were given 150 μCi of Tc-99m triethylene tetraamine polystyrene resin in cereal and were imaged in the supine position. Data were accumulated at 5-minute intervals to determine the gastric emptying time (GET). The GET results were divided into three categories: prolonged (10 patients); rapid (eight); and normal (two). Although all patients had symptoms of gastric dysfunction, only 50% had prolonged GET. This study allows the objective documentation of gastric emptying and the separation of patients with rapid or normal GET from those with prolonged GET, who might benefit from metoclopramide

[en] Extensive efforts are expended each year on research to develop methods for early cancer detection and more effective cancer therapy. Nevertheless, cancer is the second major cause of death in the U.S. today. The magnitude of the problem can be appreciated from a recent study in which it was reported that an estimated one-third of the people in the United States will develop an invasive carcinoma (excluding the epidermoid skin cancers) during their lifetime. A number of sophisticated technological advances, such as planar and SPECT nuclear imaging using different radiopharmaceuticals, transmission computerized tomography, angiography, ultrasonography, and magnetic resonance imaging, have been developed in recent years. Although these new procedures produce images with improved contrast and resolution, they have not consistently provided the information necessary to differentiate malignant lesions from other pathological conditions. Other approaches combining high sensitivity with high specificity are therefore required for cancer detection and diagnosis. Many procedures, in addition to gamma camera imaging, could use antibody-based contrast agents to improve tumor-specific image enhancement; serious consideration should be given to this option, particularly in combination with angiographic, ultrasonographic, and magnetic resonance imaging

[en] Dual isotope scintigraphy and nuclear magnetic resonance imaging produce image data that is intrinsically multispectral. That is multiple images of the same anatomic region are generated with different gray scale distribution and morphologic content that is largely redundant. Image processing technology, originally developed by NASA for satellite imaging, is available for multispectral analysis. These methods have been applied to provide tissue characterization. Tissue specific information encoded in the grapy scale data from dual isotope and NMR studies may be extracted using multispectral pattern recognition methods. The authors used table lookup minimum distance, maximum likelihood and cluster analysis techniques with data sets from Ga-67 / Tc-99m, 1-131 labeled antibodies / Tc-99m, Tc-99m perfusion / Xe-133 ventilation, and NMR studies. The results show; tissue characteristic signatures exist in dual isotope and NMR imaging, and these spectral signatures are identifiable using multispectral image analysis and provide tissue classification maps with scatter diagrams that facilitate interpretation and assist in elucidating subtle changes