Leucocyte Radiolabelling Techniques: Practical Aspects

Abstract

Radiolabeled leucocytes migrate rapidly to sites of acute inflammation. The simplest technique for imaging intestinal inflammation involves radiolabelling patients' mixed white cells ex vivo with either ^99mTc or ¹¹¹In which are then reinjected. However, further purification of mixed white cells to granulocytes is needed for optimal results using ¹¹¹In. Owing to the simpler labelling procedure, availability, image quality and dosimetry, ^99mTc-HMPAO has gained favour for the investigation of acute inflammation including inflammatory bowel disease. Because of its longer half life, ¹¹¹In is more suited to the imaging of chronic inflammation such as osteomyelitis. Attempts to radiolabel granulocytes in vivo using monoclonal anti-granulocyte antibodies have been largely unsuccessful to date, and this approach remains a challenge for the future.

Key Words:

• Indium-111
• leucocytes
• technetium-99m
• radionuclide imaging