Immunoscintigraphy using CA 125 antibodies in the management of ovarian cancer.

Radioimmundetection (RID) using anti-CA 125 antibodies proved to be a valuable tool in the follow-up of metastasizing ovarian cancer. Sensitivity, specificity, and accuracy were high. RID had no clinical side effects. But some patients formed antibodies which interfered a) with the evaluation of the scintigram and b) with further measurement of CA 125 levels. We found 2 cm diameter metastases that were not detected by computed tomography. However, the heterogeneity of tumor metastases limits the sensitivity of this method. CA 125 serum levels, immunohistochemistry, and immunoscintigraphy did not always correlate. Monitoring serum levels of CA 125 was most valuable in clinical management of tumor spread and in the optimal use of RID.