Gamma scintigraphy using Tc-99m labeled antibody to human chorionic gonadotropin

A case report is presented describing a 27-year-old woman with invasive trophoblastic hydatidiform mole metastatic to the lung. Gamma scintiscanning, using a polyclonal and monoclonal antibody specific to human chorionic gonadotropin, hCG, and labeled with Tc-99m, is described. The area of the primary lesion in the uterus was demonstrated with both antibodies tested without computer subtraction techniques; metastatic deposits in the lung were detected only with the aid of blood pool subtraction techniques.