Usefulness of imaging ovarian cancer recurrence with In-111-labeled monoclonal antibody (OC 125) specific for CA 125 antigen. The INSERM Research Network (Nantes, Rennes, Reims, Vuillejuif, Saclay

Abstract

Background: A progressive rise in serum CA 125 concentration during follow-up monitoring of ovarian cancer after treatment of primary tumor is suggestive of a recurrence.

Patients and methods: A study was carried out in 19 patients with suspected recurrence of a previously treated ovarian carcinoma. All patients underwent ultrasonography (US), computed tomography (CT) and immunoscintigraphy (IS) using F(ab')2 fragments of indium-111-labeled OC 125 monoclonal antibody (specific for CA 125 antigen). The definitive diagnosis of recurrence was made on the basis of histological data obtained at surgery.

Results: In all 15 of the 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 resection of the recurrence. IS was positive and concordant with US and/or CT 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 in 1 case.

Conclusion: Thus, immunoscintigraphy would appear to be an efficient method for detecting a recurrence early when limited involvement can make it possible for the surgeon to achieve total resection.