QUANTITATIVE-ANALYSIS OF IN-111 SATUMOMAB PENDETIDE IMMUNOSCINTIGRAPHY - AN AID TO VISUAL INTERPRETATION OF IMAGES IN PATIENTS WITH SUSPECTED CARCINOMATOSIS

The diagnosis of the diffuse intraperitoneal spread of ovarian or colo rectal carcinoma (carcinomatosis) can be difficult when based on visua l interpretation of immunoscintigraphic images alone. Twenty-nine pati ents with either colorectal or ovarian cancer were retrospectively eva luated by three technologists for carcinomatosis employing a quantitat ive analysis technique that compares uptake of In-111 satumomab pendet ide (Oncoscint CR/OV, Cytogen Corp., Princeton, NJ) in a region of int erest in the femoral vascular bundle to the uptake in two regions of i nterest in the lower abdomen, resulting in an uptake ratio (UR). All 2 9 patients underwent laparotomy after immunoscintigraphy. Of the 29 pa tients evaluated, 7 had histologically proven carcinomatosis obtained from the laparotomy. Using quantitative analysis, patients who did not have carcinomatosis had a mean uptake ratio of 1.12, and patients wit h carcinomatosis had a mean uptake ratio of 2.12. The differences betw een the means of these two groups of patients was statistically signif icant for all three technologists (P<.05). The results of this study i ndicate that there is a significant difference in uptake ratios betwee n patients with carcinomatosis and those without it, and that quantita tive analysis can be a useful adjunct to visual interpretation.