1360PSCREENING FOR MALIGNANCY WITH PET/CT SCAN IN PATIENTS WITH UNPROVOKED VENOUS THROMBOEMBOLISM

ABSTRACT Aim: To assess the value of PET/CT scan for malignancy diagnosis in patients with unprovoked venous thromboembolism (VTE) Methods: PET/CT scan performed for malignancy screening in patients with unprovoked VTE from January 2009 to October 2013 were retrospectively reviewed. Clinical history, imaging findings including conventional total body CT-scan data, and final diagnosis were analysed. Results: PET/CT scan was performed for malignancy diagnosis in 68 patients with unprovoked VTE. Thirteen patients were excluded because of prior history of carcinoma (n = 5), congenital or acquired thrombophilia (n = 5), inability to confirm VTE diagnoses (n = 2) and incomplete information (n = 1). Fifty-five patients (27 females, mean age 63 + 17 years-old) were included. VTE was a first episode in 83.6% (46/55) of cases including pulmonary embolism in 38 cases. The mean follow-up was of 10 + 11months. In 28 patients (50.9%), PET/CT scan showed increased-uptake suspicious for malignancy. After additional procedures, malignancy was confirmed in 12/28 patients including pancreatic (n = 2), ovarian (n = 2), bladder (n = 1), lung (n = 1), kidney (n = 1), breast (n = 1) and gallbladder (n = 2) cancers and non-hodgkin lymphoma (n = 2). All malignancies were diagnosed at advanced stages. Six patients died during a mean follow-up of 2.9 + 2.6 months. In all cases of confirmed malignancies, conventional CT-scan had equivalent diagnostic accuracy than PET/CT scan. In 16/28 cases, the suspected diagnosis of malignancy could not be confirmed despite extensive workup including specialist visits (n = 6), testis ultrasound (n = 1), pelvis MRI (n = 1), bone MRI (n = 1), colonic endoscopy (n = 4), lung biopsy (n = 1), endometrial biopsies (n = 2), and hysterectomy (n = 1). Interestingly, CT-scan was negative in all 16 cases and, considering only CT-scan findings, no further investigations would have been scheduled. No patients with negative PET/CT scan (n = 27) were diagnosed with cancer during follow up. Conclusions: Among subjects with unprovoked VTE conventional CT-scan was abnormal in all patients with cancer confirmed during follow-up. PET/CT scan imaging had no additive value. Furthermore, in 29% of patients with VTE, abnormal TEP imaging with normal CT scan led to unjustified, alarming, money-and time-consuming investigations. Disclosure: All authors have declared no conflicts of interest.