Elgin Ozkan, Cigdem Soydal, Mine Araz and N. Ozlem Kucuk

DOI: http://dx.doi.org/10.15379/2408-9788.2016.03.02.03

Published: 14 October 2016

Purpose: To describe the impact of fluorine (¹⁸F) - fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in detecting primary tumor focus in our patient population who had histopathologically proven metastasis.

Methods:37 patients who underwent ¹⁸F-FDG PET/CT to detect primary tumor focus in our department were included in the study. The results of PET/CT and clinical follow-up data were reviewed retrospectively. PET/CT results were compared with histological analysis and/or clinical follow-up data.

Results:Primary site of malignancy was correctly identified by PET/CT in 16 patients (16/37, 43%). Lung was the most common detected site (7/16). The mean SUV of metastatic tumor was higher than that of primary tumor. False positive and false negative results were obtained in 2 patients, respectively. In the remaining patients (17/37; 46%) the primary tumor was not localized by PET/CT. According to these results, the sensitivity and specificity of PET/CT were calculated as 89% and 90%, respectively. However, PET/CT scan determined additional metastatic focus and therapy management was changed (9/37, 24%). The primary focus was established in 4 of 8 (50%) patients with metastatic cervical adenopathy and in 12 of 29 (41%) patients with extra cervical metastases.