"Pathophysiologic mapping" of venous thromboembolism: opportunities for radiolabeled peptides

The serious clinical and economic impact of venous thromboembolic (VTE) disease is undisputed. What concerns practitioners and researchers alike is the seeming inability to truly mitigate the ramifications of VTE. Ironically, the current approaches to the diagnostic evaluation of suspected VTE patients tends to favor the application of anatomic modalities, which by virtue of their principles of detection, seemingly ignore the extensive knowledge base of VTE pathophysiology and natural history. In other words, are we seeking the appropriate types of information in patients with suspected VTE? Research in nuclear medicine techniques for detecting VTE began approximately 25 years ago. Recently, the emergence of the radiolabeled peptides as a clinically applicable technology platform has encouraged a different way of evaluating VTE. Many radiolabeled peptide candidates are undergoing preclinical and clinical research. Currently, only one, (99m)Tc-apcitide (AcuTect), has been approved (since 1998) for clinical use, specifically in the United States. Its availability this time has fueled ongoing clinical research to further elucidate the benefits of this unique peptide technology. Consequently, significant insight has been gained from large prospective clinical trials. Furthermore, this insight has kindled increasing interest in (99m)Tc-apcitide and potential new entrants into this special "diagnostic class". Unlike the more popular modalities, radiolabeled peptides circumvent many of the clinical and anatomic challenges to objectively and accurately diagnosing VTE. The importance of an objective and accurate diagnosis is understood, because it is paramount to a cost-effective treatment strategy. In addition to describing the current activities concerning the development for and use of radiolabeled peptides for clinical practice, this manuscript is intended to promulgate a thought-provoking argument for changing our current approach to the diagnostic evaluation of VTE. Despite technological and medical advances, we continue to debate controversial issues in VTE, which seemingly and arguably disproportionately, focus on treatment (i.e., who?, when?, how much? and for how long?). Should we not adopt a more robust approach to VTE problem-solving, which would logically start with the diagnosis? Perhaps the validated and perceived advantages of the radiolabeled peptides are all the rationale we need to advance beyond the status quo? Only time and continued research will tell.