Diagnosis of Deep Septic Thrombophlebitis in Cancer Patients by Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography Scanning: A Preliminary Report

PURPOSE: To determine the role of the fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) scan in the diagnosis and management of deep septic thrombophlebitis (STP). PATIENTS AND METHODS: We conducted a prospective observational evaluation of FDG-PET in patients with cancer and suspected STP. Retrospective evaluation of patients with cancer and deep venous thrombosis (DVT) who underwent FDG-PET and extremity duplex scan (DS) was also performed. RESULTS: Strong venous uptake was observed in FDG-PET of nine STP episodes versus 0 of 27 DVT episodes (P <.001). FDG-PET identified central vein STP in five patients, whereas DS and venography were negative in five and two of these patients, respectively. FDG-PET diagnosis of STP resulted in therapeutic changes in all patients. In four patients, follow-up FDG-PET confirmed resolution. CONCLUSION: In cancer patients, FDG-PET identifies STP even in areas not optimally visualized by DS or venography, distinguishes STP from DVT, and leads to significant therapeutic changes.