Radioimmunodiagnosis of ovarian cancer using 123I-labelled, tumor-associated monoclonal antibodies.

Monoclonal antibodies to epithelial cells, antigenic determinants labelled with I123 and I125, were administered to 10 immunodeficient mice bearing subcutaneous xenografts of human ovarian cancer. Radio scans of the body taken with a gamma camera at various time intervals demonstrated the presence of the cancer in all the mice. The smallest detectable tumor was approximately 1 mm in diameter. In a subsequent clinical study using 123I-labelled monoclonal antibodies in 10 patients with ovarian cancer, tumor detection was achieved in 8 patients, with tumor uptake of labelled antibody ranging between 0.2-2.6%. As a complementary method to existing forms of diagnosis, the targeting of monoclonal antibodies to ovarian cancer cells in vivo raises the hope of achieving early diagnosis in otherwise undetectable ovarian cancer, and provides encouragement to the concept of selective therapy in oncology.