The radiation dosimetry and normal value study of 99mTc-HMPAO-labeled leukocytes.
OBJECTIVE
Indium-111 (111In)-labeled leukocyte scanning has been used frequently in patients suspected of having infections. Recently, technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) has been used to label leukocytes. This study was undertaken to determine the distribution and dosimetry of 99mTc-HMPAO leukocytes in healthy subjects.


METHODS
Five healthy volunteers had leukocytes labeled with 99mTc-HMPAO. After injection of the labeled leukocytes, whole body images and blood and urine samples were obtained at multiple time points.


RESULTS
Visual interpretation of the images demonstrated significant bowel activity as early as 2 hours and increasing with time such that one the 8- and 24-hour images, the amount of bowel activity would preclude using 99mTc-HMPAO leukocyte scanning for abdominal processes. The dosimetry for this study is similar to that of other studies and is in an acceptable diagnostic range.


CONCLUSIONS
99mTc-HMPAO leukocyte studies are an acceptable alternative to 111In-labeled leukocyte studies in terms of dosimetry. Use of such studies in the abdomen should be limited to early images, usually before 2 hours, to avoid confusion with the normal route of excretion in the bowel.
Department of Diagnostic Radiology, Mayo Clinic and Foundation, Rochester, Minnesota.
M L
ML
Brown
J C
JC
Hung
R J
RJ
Vetter
M K
MK
O'Connor
S
S
Chowdhury
L A
LA
Forstrom
D005260:Female; D006801:Humans; D007239:Infections / Q000000981:diagnostic imaging; D007962:Leukocytes; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D010091:Oximes; D011829:Radiation Dosage; D011835:Radiation Protection; D011877:Radionuclide Imaging; D012016:Reference Values; D019690:Technetium Tc 99m Exametazime; D013997:Time Factors; D014018:Tissue Distribution
D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime