Impact of Antigen Levels on Antibody Imaging in Cancer
Author Information
Author(s): B.R. Davidson, J. Babich, H. Young, W. Waddington, G. Clarke, M. Short, P. Boulos, J. Styles, C. Dean
Primary Institution: University College and Middlesex School of Medicine
Hypothesis
How do circulating antigen levels affect the biodistribution and imaging of radiolabelled antibodies in cancer patients?
Conclusion
The study found that successful antibody imaging can occur even with high levels of circulating antigens, but large doses of unlabelled antibodies are necessary to mitigate immune complex formation.
Supporting Evidence
- Patients with high circulating antigen levels had high tumor uptakes of radiolabelled antibody.
- Administration of cold MAb increased splenic uptake but did not affect tumor uptake.
- Chelate administration reduced urinary excretion of radioactivity but increased liver uptake.
Takeaway
This study shows that even when there are a lot of antigens in the blood, doctors can still see tumors using special antibodies, but they need to give a lot of extra antibodies to help.
Methodology
Patients were divided into three groups receiving different treatments before imaging, and the uptake of radiolabelled antibodies was measured in various organs.
Limitations
The study did not find significant improvements in imaging despite the administration of cold antibodies, suggesting that larger doses may be necessary.
Participant Demographics
Patients undergoing immunoscintigraphy for known or suspected colorectal cancer, aged 51 to 83.
Statistical Information
P-Value
p=0.005; p=0.034; p=0.000
Statistical Significance
p<0.05
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