New observation of early detection of venous thromboembolism by FDG PET/CT in patients with multiple myeloma

Abstract

Objectives: Deep vein thrombosis (DVT) and acute pulmonary embolism (PE) are two manifestations of venous thromboembolism (VTE). Early detection of VTE by FDG PET/CT allowing earlier actions may prevent further DVT, PE and potential high-risk management. This study is to investigate early FDG PET/CT evidence of VTE among cancer patients with clinical VTE diagnosis. Methods: A total of 39 whole-body FDG-PET/CT scans of 10 multiple myeloma patients with clinical VTE diagnosis according to duplex ultrasound (DUS) and/or CT angiography (CTA) were reviewed and compared to DUS and CTA. All subjects had a FDG PET/CT scan at the time of VTE diagnosis and several before and after. Results: 4 patients had DVT, 2 had PE, and 4 had both PE and DVT. In 9/10 cases, VTE associated FDG uptake was present on scans performed at the time of diagnosis as well as in all scans performed prior to DUS and CTA (up to several months). In the one case with no FDG evidence of VTE, subsequent DUS were also negative, and CTA was reassessed; PE was retrospectively considered to be a misinterpretation of posttraumatic lesions. FDG only visualized PE directly in 1 of 5 cases with CTA-confirmed PE, but all cases showed clear evidence of DVT. In 3/4 cases of upper extremity or neck vein VTE, FDG-PET/CT showed additional VTE in the lower extremities. Conclusions: FDG PET/CT appeared to be sensitive for early detection of DVT processes, even in pre-symptomatic patients. Therefore, incidental findings suggestive of VTE in cancer patients should be reported and considered by clinicians. We suggest when there is no FDG evidence of DVT in patients suspected of PE, other possibilities should be investigated.