Clinical value of radioimmunoscintigraphy in the follow-up of ovarian carcinoma: a prospective study.

Twenty-five patients treated with debulking surgery and chemotherapy for ovarian cancer were prospectively studied to evaluate the efficacy of radioimmunoscintigraphy (RIS) in detecting residual tumor before second-look surgery. RIS was performed with the monoclonal antibody OC125 F(ab')2 labelled with I-131 without knowledge of clinical data and compared with subsequent surgical results. Second look showed tumor persistence in 12 patients, mostly characterized by small lesions. The overall diagnostic sensitivity of RIS was 50% and the specificity was 85%. In particular, RIS showed better sensitivity for pelvic tumor localizations than for abdominal sites (73% vs 33%); this was due to the inability of RIS to detect upper abdominal lesions. Therefore, our conclusion is that, at present, RIS cannot substitute surgical second-look in the management of ovarian cancer, however, considering that also ultrasonography, computer tomography and magnetic resonance are not always able to give definite diagnostic evidence in the follow-up of ovarian carcinoma, RIS could be added to these procedures to balance the limitations of each method. In this regard, the best application of RIS could be in the follow-up of patients with marker elevation without clinical evidence of disease, especially in the case of pelvic fibrosis or adhesions due to previous therapy, where the other non-invasive tools can give doubtful diagnostic results.