Utility of F-18 fluorodeoxyglucose posıtron emıssıon tomography/computed ın carcınoma of unknown primary

• Published in: International journal of clinical and experimental pathology Vol. 7; no. 12; pp. 8941 - 8946
• Main Authors: Elboga, Umut, Kervancioğlu, Selim, Sahin, Ertan, Basibuyuk, Mustafa, Celen, Y Zeki, Aktolun, Cumali
• Format: Journal Article
• Language: English
• Published: United States e-Century Publishing Corporation 01-01-2014
• Subjects: Adult; Aged; Aged, 80 and over; Female; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Multimodal Imaging - methods; Neoplasms, Unknown Primary - diagnostic imaging; Original; Positron-Emission Tomography - methods; Radioisotopes; Tomography, X-Ray Computed - methods; Young Adult; metastases; treatment change; Carcinoma of unknown primary; F-18 FDG PET/CT
• ISSN: 1936-2625

Carcinoma of unknown primary (CUP) is a heterogeneous group of tumors with various clinical features causing diagnostic and therapeutic challenges. The aim of this study was to evaluate the ability of F-18 FDG PET/CT for localizing the primary tumor, disclosing additional metastases, and changing the treatment in patients with CUP. One hundred and twelve metastatic patients (female = 40, male = 72, median age = 60.5 years) in whom conventional diagnostic work-up failed to disclose the primary tumor were included in the study. F-18 FDG PET/CT imaging was performed in a standard protocol (patient supine, arms on patient's side, vertex to thigh, 369.3 MBq (296-444 MBq) F-18 FDG, a 60-minute uptake period, 6-7 bed position). Histopathology was taken as the only reference standard. F-18 FDG PET/CT correctly detected primary tumor in 37 of 112 (33.03%) patients. The most common site of primary tumor detected by F-18 FDG PET/CT was lung (n = 18), which was followed by nasopharynx (n = 7), pancreas (n = 5), tonsil (n = 2), breast (n = 2), thyroid (n = 1), uterus (n = 1) and colon/rectum (n = 1). F-18 FDG PET/CT imaging disclosed additional previously undetected metastases in 32 (28.5%) and changed the treatment in 33 (29.4%) of 112 patients. There were false positive F-18 FDG PET/CT results in 21 (18.5%) patients. F-18 FDG PET/CT is able to disclose the primary tumor, disclose new metatases and change the treatment in about one third of patients with CUP.