Radioimmunodetection in patients with suspected ovarian cancer

Twenty-five patients, having either unilateral ovarian tumors of unknown etiology or suspected of having ovarian cancer recurrence were investigated by the method of immunoscintigraphy to rule out primary and/or metastatic tumor sites. Four-hundred micrograms of the tumor-associated monoclonal mouse antibody HMFG-2, raised against human milk fat globulin membranes and labeled with 123I, were used for each patient to display the tumor sites by external scintigraphy. The dose ranged between 0.5 and 2.2 mCi, the specific activity between 1.25 and 5.5 mCi per mg of antibody. Nineteen of the patients underwent operations a few days after immunoscintigraphy. The remaining six patients were investigated by transmission computed tomography (TCT) to establish the presence or absence of tumor of the imaging. In 22 of the 25 cases the scintigraphic results correlated with the situation found at the subsequent operation, or by TCT, respectively, as well as with the histological diagnosis of the tumor type. Overall, there were just two false-negative and one false-positive scan report, the latter due to faulty reading of the scintigrams. Sixteen out of 18 tumor sites in 25 patients could be revealed by immunoscintigraphy, the smallest one being 1.5 cm in diam. In four of the patients immunoscintigraphy was the only noninvasive investigation method that could reveal the malignant tumor sites prior to the operation.