Radioimmunolocalization of tumours by external scintigraphy after administration of 131I antibody to human chorionic gonadotrophin: preliminary communication.

(131)Iodine ((131)I) labelled antibody directed against human chorionic gonadatrophin (hCG) was given on 21 occasions to 18 patients with hCG-producing neoplasms. Tumours were localized by external scintigraphy in 13 of 21 investigations. Positive results were obtained reliably when serum hCG exceeded 500 miu/ml and in some cases sensitivity was comparable to that of computerized tomography. A positive result probably implies viability in the tumour and this was of practical value in discriminating between necrotic deposits and living tumour before surgery.