title: Utility of F-18 fluorodeoxyglucose posıtron emıssıon tomography/computed ın carcınoma of unknown primary.
abstract: 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.
authors: Department of Nuclear Medicine, Gaziantep University Gaziantep, Turkey.
authors: Umut
authors: U
authors: Elboga
authors: Department of Radiology, Gaziantep University Gaziantep, Turkey.
authors: Selim
authors: S
authors: Kervancioğlu
authors: Department of Nuclear Medicine, Namik Kemal University Gaziantep, Turkey.
authors: Ertan
authors: E
authors: Sahin
authors: Department of Nuclear Medicine, Gaziantep University Gaziantep, Turkey.
authors: Mustafa
authors: M
authors: Basibuyuk
authors: Department of Nuclear Medicine, Gaziantep University Gaziantep, Turkey.
authors: Y Zeki
authors: YZ
authors: Celen
authors: Department of Radiology, Molecular Imagıng Program at Stanford (MIPS), Clark Center, Stanford University Palo Alto, CA, USA.
authors: Cumali
authors: C
authors: Aktolun
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D009382:Neoplasms, Unknown Primary / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography / Q000379:methods; D011868:Radioisotopes; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult
chemical_list: D011868:Radioisotopes; D019788:Fluorodeoxyglucose F18
keywords: Carcinoma of unknown primary; F-18 FDG PET/CT; metastases; treatment change