There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
Technetium-99m hexamethylpropylene amine oxime (HMPAO)-labeled leukocytes are well
established for the investigation of inflammatory disease. Their kinetics and normal
distribution are similar to those of indium-111-labeled leukocytes except for nonspecific
activity in urine, kidneys, gall bladder, and bowel, which results from the elution
of secondary 99mTc-labeled HMPAO complexes. The principal clinical indications for
[99mTc]HMPAO-leukocytes include inflammatory bowel disease (IBD), osteomyelitis, soft
tissue sepsis, and, to a lesser extent, occult fever. The superior resolution and
count density of 99mTc places [99mTc]HMPAO-leukocytes at an advantage over 111In-leukocytes
in IBD, especially for the identification of small bowel involvement in patients with
Crohn's disease. However, quantification of disease activity is more difficult than
with 111In. Technetium-99m HMPAO-leukocytes are indicated for most forms of acute
soft tissue and abdominal sepsis, although when compared with 111In, it may be more
difficult to demonstrate communication between an abdominal abscess and bowel lumen.
Chronic osteomyelitis, including infected joint prostheses, are better approached
with 111In-labeled leukocytes. Occult fever and fever of unknown origin (FUO) are
more controversial. There is still a place for gallium-67 in FUO, of which there is
a wide spectrum of causes. Occult fever implies a pyogenic cause for an undiagnosed
fever and should probably be imaged with 111In-leukocytes. With the advances being
made in other imaging modalities and in interventional radiology, there is a clear
need for radionuclide agents that can be used for whole-body screening in patients
with undiagnosed fever. Such agents may include fluorine-18-fluorodeoxy-glucose and
radiolabeled monoclonal antibodies to endothelial adhesion molecules activated at
the foci of inflammation.