|Budget Amount *help
¥1,300,000 (Direct Cost : ¥1,300,000)
Fiscal Year 1992 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1991 : ¥700,000 (Direct Cost : ¥700,000)
Imaging using radiolabeled monoclonal antibody(MAb) to tumorassociated antigen is potentially specific approach to qualitative diagnosis. We Produced MAbCEA102 against CEA by immunization with purified CEA, and applied to 20 cases with colorectal cancer. This method was useful to distinguish postoperative fibrosis from local recurrence. Another experiment was performed to investigate the specific accumulation of radiolabeled CEA102 using Fuji Computed Radiography(FCR). Autoradiogram by FCR showed predominant localization of ^<131>I-CEA102 in primary tumor and even small liver metastases. Although the above results demonstrated that radioimaging was useful to qualitative diagnosis, many technical problems confront its clinical application. In this study, we compared F(ab')2 fragments with whole lgG, and used ^<111>In as a radiotracer, and Emission CT as an extra scanner. F(ab')2 were eliminated from the circulation twice as fast as whole IgG, and demonstrated clear image on the 1st day after injection, but 3rd to 4th day in whole IgG. ^<111>In was accumulated in liver more than 1 week, but suitable tools to diagnose local recurrence of rectal cancer using Emission CT.