Immunoscintigraphy of colo-rectal tumors with the monoclonal antibody BW 431/31

The activity ratio of 81Rb and its short-lived daughter product sup(81m)Kr meet the requirements for direct measurements of organ perfusion. Because of the short half-life of sup(81m)Kr the deviation from radioactive equilibrium is only 25 % at a perfusion rate of 100 ml/min x 100 g. We used a SPECT system with simultaneous recording in the two energy windows of 81Rb and sup(81m)Kr. As the tomograms are without superposition by other tissues, the potentials of 81Rb-sup(81m)Kr can be fully utilized. In 106 patients we found Rb-Kr tomograms recorded at rest to differentiate between sites of infarction and regions of ischemia. All examinations were compared with coronary angiography and some of them also with 201Tl scintigraphy. The method can also be used for demonstrating the benefits of coronary dilatation and bypass surgery. (Author)