USEFULNESS OF IMAGING OVARIAN-CANCER RECURRENCE WITH IN-111 LABELED MONOCLONAL-ANTIBODY (OC-125) SPECIFIC FOR CA-125 ANTIGEN

Background: A progressive rise in serum CA 125 concentration during fo llow-up monitoring of ovarian cancer after treatment of primary tumor is suggestive of a recurrence. Patients and methods: A study was carri ed out in 19 patients with suspected recurrence of a previously treate d ovarian carcinoma. All patients underwent ultrasonography (US), comp uted tomography (CT) and immunoscintigraphy (IS) using F(ab')2 fragmen ts of indium-111-labeled OC 125 monoclonal antibody (specific for CA 1 25 antigen). The definitive diagnosis of recurrence was made on the ba sis of histological data obtained at surgery. Results: In all 15 of th e patients with recurrence, all three of the imaging methods had false negative results once. In 7 patients, only the IS method had positive results; six of these 7 benefited from a macroscopically total resect ion of the recurrence. IS was positive and concordant with US and/or C T in 7 further patients. Two of them benefited from a total resection of their recurrence. The usefulness of IS was more evident when serum CA 125 concentration was below 500 U/ml. The absence of recurrence was correctly indicated by IS and CT in 1 case and by IS associated with negative US and CT in 2 other cases. IS and CT were falsely positive i n 1 case. Conclusion: Thus, immunoscintigraphy would appear to be an e fficient method for detecting a recurrence early when limited involvem ent can make it possible for the surgeon to achieve total resection.