Comparison of early and delayed scintigraphy with 99mTc-apcitide and correlation with contrast-enhanced venography in detection of acute deep vein thrombosis.
Preliminary studies with 99mTc-apcitide (99mTc-P280), a synthetic peptide that binds to glycoprotein IIb/IIIa receptors expressed on activated platelets, have shown promising results in the detection of acute deep vein thrombosis (ADVT). The purpose of this study was to compare the diagnostic value of early and delayed imaging with 99mTc-apcitide in patients with suspected ADVT, using contrast-enhanced venography as the gold standard.


METHODS
Thirty-nine patients (17 women, 22 men; mean age 59 y) with signs or symptoms suggestive of ADVT (within 10 d of onset) and scheduled for contrast-enhanced venography were prospectively studied. The patients were injected with approximately 740 MBq (20 mCi) 99mTc-apcitide within 36 h of contrast-enhanced venography. Both anterior and posterior planar images (8-10 min/view) of the lower extremities using a dual-head gamma camera were obtained at 10, 60 and 120 min after the injection of 99mTc-apcitide. The three sets of images initially were interpreted randomly and separately by three experienced observers unaware of the clinical history, the site of ADVT and results of contrast-enhanced venography. All images from the three sets for a given patient were then analyzed together during a second session. Conventional contrast-enhanced venography was performed on 31 patients before 99mTc-apcitide scintigraphy and in the remaining 8 patients after 99mTc-apcitide scintigraphy. 99mTc-apcitide findings were considered positive forADVT when a focus of increased uptake was found to correspond to the location of a deep vein. Disagreements were resolved by consensus.


RESULTS
Twenty-two patients had ADVT observed on contrast-enhanced venography, whereas 17 had normal findings. Six cases of ADVT were infrapopliteal. One patient did not complete the third set of images with 99mTc-apcitide. The sensitivity of 99mTc-apcitide in detecting ADVT was 63.6% (14/22), 68.2% (15/22), 76.2% (16/21) and 86.4% (19/22) for images obtained at 10, 60 and 120 min and for the three sets analyzed together, respectively. The specificity was 82.4% (14/17), 76.5% (13/17), 88.2% (15/17) and 88.2% (15/17) for images obtained at 10, 60 and 120 min and for the three sets of images together, respectively.


CONCLUSIONS
Although the set of 99mTc-apcitide images obtained 120 min after injection showed good overall diagnostic accuracy, the combination of at least two sets of images provided the highest accuracy in detecting ADVT.
Taillefer
R
R
Department of Nuclear Medicine, Centre Hospitalier de l'Université de Montréal, Canada.
Thérasse
E
E
Turpin
S
S
Lambert
R
R
Robillard
P
P
Soulez
G
G
D000208:Acute Disease; D003287:Contrast Media; D005260:Female; D006801:Humans; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D010456:Peptides, Cyclic; D010690:Phlebography; D011446:Prospective Studies; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity; D013997:Time Factors; D020246:Venous Thrombosis / Q000000981:diagnostic imaging*
D003287:Contrast Media; D015609:Organotechnetium Compounds; D010456:Peptides, Cyclic; C094919:technetium Tc 99m P280