J.Jpn. Surg. Soc.
ISSN 1880-1129

[Abstract] [Full Text PDF] （in Japanese / 674KB） [Members Only And Two Factor Auth.]

J.Jpn. Surg. Soc.. 93(3): 266-273, 1992

Original article

RADIOIMMUNODETECTION OF COLORECTAL CANCER, USING ANTI-CEA MONOCLONAL ANTIBODY CEA 102: WHOLE lgG VERSUS F(ab')2 FRAGMENTS

1) The Second Department of Surgery, Nagoya University School of Medicine, Nagoya, Japan
2) Department of Radiology, Nagoya University School of Medicine, Nagoya, Japan
3) The Department of Gastrointestinal Surgery, Aichi Cancer Center Hospital, Nagoya, Japan
4) The Department of Surgery, Nagoya National Hospital, Nagoya, Japan

Kimio Wada1), Tadashi Watanabe, Masanori Tadokoro2), Junichi Sakamoto3), Hiroki Murayama4), Sadayuki Sakuma2), Hiroshi Takagi1)

In order to improve cancer imaging with radiolabeled antibodies, three factors appeared to be of particular importance: (1) The selection of the most favorable monoclonal antibody directed to tumor-associated antigen. (2) The use of F(ab')2 or Fab fragments. (3) Selection of the most convenient isotope.
Monoclonal antibody CEA 102 was produced by immunization by purified CEA, and its F(ab')2 fragments were compared with whole lgG as a radiotracer for radioimmunodetection of the colorectal cancer. Fragments were eliminated from the circulation twice as fast as whole lgG, and tumor-to-background ratio was achieved more than 1 at 2-3 days with F(ab')2, but 6-7 days with whole lgG in tumor bearing nude mice. In clinical study, F(ab')2 demonstrated clear image on the 1 at day after injection, whereas achievement of the image was possible on the 3rd day in whole lgG. These results indicated that fragments are preferred over whole lgG. Therefore fragments make it possible to preclude dualisotope subtraction methods, and omit the long delays before imaging. They also make it possible to use short half life radionuclides with excellent photon properties, such as 123I and 99mTc.

<< To previous pageTo next page >>

To read the PDF file you will need Adobe Reader installed on your computer.