CLINICAL EVALUATION OF TUMOR POSITIVE IMAGING WITH I-125 (or-131) LABELED ANTI-HUMAN AFP SPECIFIC ANTIBODY FOR AFP PRODUCING TUMOR LINE (JTG-1) AND CLINICAL CASES

Abstract

The present study was carried out to study the feasibility of the specific tumor positive imaging by the labeled anti-human AFP specific antibody (AAA) with the AFP producing tumor line JTG-1 and in two clinical cases. I-125-labeled AAA (0.68mg, 12μCi for a mouse) injected to five mice. The serial whole body imaging was performed with the pin hole collimator of the scintillation camera in each serial time of 1, 3, 5 and 8 days after administration. I-131-labeled AAA (0.2mg, 415μCi for a patient) was also injected to two patients. The serial whole body imaging was performed with the PHO/CON TM-Multi-Plane Imager System in each serial time of 1, 3 and 5 days after administration.
No preferential localization of labeled AAA in the tumor was observed 24 hours after administration. However, the radioactivity was recognized in the tumor tissue 3 days after administration and it was gradually accumulated. The satisfying tumor positive images could be obtained 5 and 8 days after administration.
The results of PHO/CON serial tomoscintiphotos in two clinical cases with metastases were unsatisfactory. The scintiphotos in 24 hours after administration demonstrated the kidney, the urinary bladder and the lung in the 2 cases but the thyroid gland in only one case. No accumulation was observed in any specific area except the thyroid gland 1, 3 and 5 days after administration. The preferential localization of the labeled AAA was not recognized in the metastatic lesion. We thought that the difference of the tumor imaging between nude mice and clinical cases depended upon the dose of the labeled AAA and the histological changes by the chemotherapy with cis-diaminodichloro platinum.