Clinical assessment of 111In-CYT-103 immunoscintigraphy in ovarian cancer

The ability of 111In-CYT-103 immunoscintigraphy to aid in the diagnosis of patients with primary or recurrent/residual ovarian cancer was evaluated in a multicenter trial. The 111In-labeled immunoconjugate of the monoclonal antibody B72.3 was prepared using a site-specific conjugation method. A total of 103 patients received a 1 mg infusion of 111In-CYT-103 and subsequently underwent surgery or biopsy. The infusion of 111In-CYT-103 was well tolerated; only 1 patient experienced a modest elevation in blood pressure that was likely related to the infusion. 111In-CYT-103 immunoscintigraphy correctly identified surgically confirmed tumor in 68% of patients with ovarian adenocarcinoma. The sensitivity of 111In-CYT-103 immunoscintigraphy was positively influenced both by the size of the tumor lesion and the tumor TAG-72 antigen expression. The overall sensitivity of 111In-CYT-103 immunoscintigraphy was greater than that of CT imaging (44%). Antibody imaging detected occult disease in 20 of 71 patients with surgically documented ovarian adenocarcinoma; 6 patients being evaluated after initial surgery and chemotherapy had an otherwise negative presurgical workup and a normal CA 125 serum level. The results of this trial also indicate that 111In-CYT-103 immunoscintigraphy can contribute to the medical and surgical management of some patients with ovarian cancer. The results of this trial indicate that 111In-CYT-103 immunoscintigraphy should be a valuable addition to the presurgical evaluation of patients with suspected persistent or recurrent ovarian cancer.