Detecting deep venous thrombosis with technetium-99m-labeled synthetic peptide P280

Scintigraphy, using small, thrombus-avid, synthetic peptides labeled with gamma-emitting nuclides is an innovative approach to the noninvasive detection of acute deep venous thrombosis (DVT). The goal of this study was to evaluate clinically ^99mTc-P280 for imaging DVT. The peptide P280 is a 26 amino acid dimer that binds with high affinity to the GPIIb/IIIa receptor expressed on activated platelets and can be labeled with ^99mTc. Methods: Scintigraphy with ^99mTc-P280 (10-22 mCi) was performed in nine patients with clinical suspicion and diagnostic evidence of DVT. Planar and tomographic images of the legs, abdomen/pelvis, chest and head were obtained immediately, 1, 2, 4 and 24 hr after injection. Results: No adverse effects were noted after ^99mTc-P280 administration in any patient. Positive visualization of thrombi occurred in eight of nine cases with confirmed DVT within 1 hr of tracer injection. The majority of the patients had recent onset of DVT symptoms (less than 3 wk), while the only negative case was diagnosed 42 days earlier and was likely related to an accident 7 mo earlier. Thrombi-to-background ratios were essentially constant over the study. Technetium-99m-P280 accumulation was also discernible in two patients with pulmonary embolism, while in a third patient the radiotracer concentrated in a cerebellar hemangioblastoma. Conclusion: These human studies indicate that ^99mTc-P280 is a potentially safe and sensitive procedure for diagnosing DVT and pulmonary embolism. It also may have substantial utility in monitoring active venous thrombosis.