Is 99mTc-LeucoScan scintigraphy useful in the assessment of location in Crohn’s disease?
Background/Aims: Scintigraphy with 99mTechnetium
HMPAO labelled white blood cells (99mTc HMPAO-WBC)
is routinely used for the assessment of inflammatory bowel
disease (IBD). The main disadvantages of this diagnostic
test are the time consuming in vitro cell labelling and the
handling of blood itself. To overcome these problems, new,
equally effective agents are under development. To assess
the value of a new, easily prepared agent, the 99mTc-
Leucoscan, in IBD, we performed a pilot scintigraphic study
in patients with active Crohns disease (CD). In the event
of negative results, it was envisaged, that another agent 99mTc
(V) dimercaptosuccinic acid (DMSA) would be tested.
Patients - Method: We performed 99mTc-Leucoscan
scintigraphy in 7 patients with clinically active CD and in 3
of them an additional scintigraphy with 99mTc (V) DMSA.
Two of the 7 patients were males and 5 females; aged 26-70
years (mean age 42 years). Two of them had extra-intestinal
manifestations with joint involvement.
Results: In one of these patients 99mTc-Leucoscan scintigraphy
was considered as indeterminate because of
relatively increased uptake in the bowel and in the other 6
it was false negative. In the 2 patients with joint involvement
99mTc-Leucoscan images did show increased uptake in the involved bone areas. Three of all patients subsequently
underwent 99mTc (V) DMSA scintigraphy and all 3 were
considered true positive.
Conclusion: Our study concludes that 99mTc-Leucoscan
scintigraphy has no place in the assessment of gastrointestinal
inflammation in CD. 99mTc (V) DMSA could be suggested as
a reliable tracer that could substitute for 99mTc-HMPAO
WBC scintigraphy in IBD patients.
Key Words: Crohns disease, 99mTc-Leucoscan, 99m Tc (V)
DMSA, Scintigraphy, Intestinal inflammation.