Monoclonal antibodies in ovarian and prostate cancer

Radioimmunoscintigraphy (RIS)--using radiolabeled monoclonal antibodies (MoAbs) to image disease--is a growing subspecialty of nuclear medicine. RIS of the reproductive tracts of men and women has shown encouraging results in imaging both primary lesions and metastases of these cancers. Ovarian cancer is the most fatal gynecologic cancer in the United States, and prostate cancer is the most prevalent form of cancer in men. Several MoAbs against reproductive tumor antigens were used with limited success in clinical trials before 1989. Most recently, MoAbs CYT-103 (satumomab pendetide) and OV-TL 3 have shown promise as safe, sensitive imaging tools for ovarian cancer. Although to date more agents have been used to image ovarian carcinoma than prostate cancer, research has been restimulated in prostate carcinoma imaging because of development of a promising MoAb conjugate, CYT-356. Radionuclide indium-111 appears to be the most promising radiolabeled to date for ovarian and prostate carcinoma RIS performed in the United States. In future clinical trials, consideration of safety issues and a standardization of methods among institutions using RIS are needed before the use of MoAb technology in cancer imaging will become routine. Comparative studies with more traditional methods like computed tomography are needed, as well as more trials comparing radioimmunoscintigraphic findings with pathological evidence.