Efficacy of FDG PET/CT imaging for venous thromboembolic disorders: preliminary results from a prospective, observational pilot study.

PURPOSE: In recent years, several case reports have described venous thromboembolism (VTE) on FDG PET/CT. In this short communication, we present results from a proof-of-concept pilot study aimed at providing some preliminary data on the efficacy of FDG PET/CT in prospective patients with suspected VTE. PATIENTS AND METHODS: Fifteen patients with suspected deep venous thrombosis (DVT) and/or pulmonary embolism (PE) were included prospectively and underwent a whole-body FDG PET/CT. Patients were divided into 4 groups as follows: DVT+ (DVT proven by high clinical suspicion and positive compression ultrasound), DVT- (DVT ruled out by low clinical suspicion and negative compression ultrasound), PE+ (PE proven by high clinical suspicion and positive lung scintigraphy), and PE- (PE ruled out by low clinical suspicion and normal lung scintigraphy). Images were interpreted visually by 2 experienced nuclear medicine physicians independently and without knowledge of other imaging results. RESULTS: Seven DVT+, 6 DVT-, 6 PE+, and 1 PE- were included. Five patients were suspected of both DVT and PE. FDG PET/CT correctly diagnosed the presence or lack of DVT in all patients, whereas results are more ambiguous in PE with only 2 of 6 PE patients showing FDG avidity. The readers agreed in all cases. CONCLUSIONS: Although further studies are warranted for further clarification, our preliminary data substantiate that FDG PET/CT is a viable modality for assessing VTE, at least for DVT. We believe our results add positively to the limited data on this subject and are promising enough to warrant further larger series.

Tumor thrombus: ancillary findings on FDG PET/CT in an oncologic population.

PURPOSE: Thrombosis in cancer may manifest itself as venous thromboembolic disease or tumor thrombosis (TT). We present our experience with incidentally detected TT on FDG PET/CT in 21 oncologic patients. PATIENTS AND METHODS: We retrospectively reviewed all FDG PET/CT examinations during a 5-year period at the Army Hospital Research and Referral in New Delhi, India, and included all oncology cases with FDG-avid thrombosis in the report. The diagnosis of TT was based on FDG-avid solid masses inside the vessels in patients with known malignancy. The SUVmax was calculated. RESULTS: Twenty-one patients were included; the most common malignancies were renal cell carcinoma (n=6), hepatocellular carcinoma (n=3), and lung cancer (n=3). Indication for the scan was initial staging (n=15) and suspected recurrence (n=6). Several vessels were affected, the most common was the inferior vena cava (n=14), but most other major branches of the venous vasculature was represented, and some patients had thrombi in several vessels. FDG uptake was linear in 7 patients, linear with a dilated vessel in 6 patients, and focal in 7 patients. The mean SUVmax of the primary tumors was 10.3 (range, 2.6-31.2; median, 6.9), and the mean SUVmax of the thrombi was 7.85 (range, 1.7-23.2; median, 6.1). All but 2 patients had additional FDG-avid foci besides the thrombus. CONCLUSIONS: This study supports results from other smaller studies regarding the usefulness of FDG PET/CT in TT and corroborates the hypothesis that the SUVmax and the patterns of FDG uptake can be helpful for differentiating BT from TT in oncological patients.

Historic images in nuclear medicine: 1976: the first issue of clinical nuclear medicine and the first human FDG study.

In 1976, 2 major molecular imaging events coincidentally took place: Clinical Nuclear Medicine was first published in June, and in August researchers at the Hospital of the University of Pennsylvania created the first images in humans with F-FDG. FDG was initially developed as part of an evolution set in motion by fundamental research studies with positron-emitting tracers in the 1950s by Michel Ter-Pegossian and coworkers at the Washington University. Today, Clinical Nuclear Medicine is a valued scientific contributor to the molecular imaging community, and FDG PET is considered the backbone of this evolving and exciting discipline.