PET with FDG-labeled leukocytes versus scintigraphy with 111In-oxine-labeled leukocytes for detection of infection.
OBJECTIVE
To compare prospectively the accuracy of positron emission tomography (PET) with leukocytes labeled in vitro with (18)F fluorodeoxyglucose (FDG) versus that of conventional scintigraphy with leukocytes labeled in vitro with (111)In oxine in patients suspected of having infection.


METHODS
This HIPAA-compliant study had institutional review board approval; informed consent was obtained from all patients. Patients were 25 men and 26 women aged 32-86 years. In vitro labeling of autologous human leukocytes with FDG and (111)In-oxine was performed according to published methods. Labeling efficiencies and cell viability were determined. Imaging was performed 2.5-5.8 hours after injection of 196-315 MBq of FDG-labeled leukocytes and approximately 24 hours after injection of 17-25 MBq of (111)In-oxine-labeled leukocytes. Forty-three (20 men, 23 women; mean age, 59 years; range, 32-86 years) patients could be successfully imaged with both tracers. Six patients were not injected with FDG-labeled leukocytes because of low labeling efficiency (<35%). Two patients were injected with FDG-labeled leukocytes but were not imaged. One reader interpreted all results as positive or negative for infection. Imaging results were compared with final diagnoses. Labeling efficiencies and cell viabilities were compared by using the paired t test. Differences between PET and scintigraphy were determined by using the McNemar test.


RESULTS
For the 43 patients who were imaged with both tracers, labeling efficiency of FDG was lower than that of (111)In oxine (72% +/- 8 [standard deviation] vs 90% +/- 5, P < .001). Viability of FDG-labeled leukocytes was not different from that of (111)In-oxine-labeled leukocytes (98% +/- 1 vs 97% +/- 3). There were no differences between FDG PET and (111)In scintigraphy in terms of sensitivity (87% vs 73%), specificity (82% vs 86%), or accuracy (84% vs 81%).


CONCLUSIONS
PET with FDG-labeled leukocytes was comparable to scintigraphy with (111)In-oxine-labeled leukocytes. Further investigation in a larger population with dedicated PET or PET/computed tomography seems warranted.
Rini
Josephine N
JN
Division of Nuclear Medicine, Division of Infectious Diseases, Division of Vascular Surgery, Long Island Jewish Medical Center, New Hyde Park, NY 11040, USA. rini@LIJ.edu
Bhargava
Kuldeep K
KK
Tronco
Gene G
GG
Singer
Carol
C
Caprioli
Russell
R
Marwin
Scott E
SE
Richardson
Hugh L
HL
Nichols
Kenneth J
KJ
Pugliese
Paul V
PV
Palestro
Christopher J
CJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D066298:In Vitro Techniques; D007205:Indium Radioisotopes; D007239:Infections / Q000000981:diagnostic imaging*; D007962:Leukocytes; D008297:Male; D008875:Middle Aged; D015125:Oxyquinoline / Q000493:pharmacokinetics; D011446:Prospective Studies; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D014055:Tomography, Emission-Computed
D007205:Indium Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D015125:Oxyquinoline