Mehrdad Bakhshayeshkaram - Department of Radiology, Shahid Beheshti University of Medical Sciences, Tehran, Iran- Pediatric Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Tehran, Iran
Farahnaz Aghahosseini - Department of Radiology, Shahid Beheshti University of Medical Sciences, Tehran, Iran- Pediatric Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Tehran, Iran
Sara Alavinejad - Department of Radiology, Shahid Beheshti University of Medical Sciences, Tehran, Iran- Pediatric Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Tehran, Iran
Yalda Salehi - Department of Nuclear Medicine, Tehran University of Medical Sciences, Tehran, Iran
Sharareh Seifi - Department of Radiology, Shahid Beheshti University of Medical Sciences, Tehran, Iran- Pediatric Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Tehran, Iran
Maryam Hassanzad - Department of Radiology, Shahid Beheshti University of Medical Sciences, Tehran, Iran- Pediatric Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Tehran, Iran

Background: The aim of the present study was to investigate the added value ofF-۱۸ fludeoxyglucose (FDG) positron-emission tomography (PET)/computedtomography (CT) compared with conventional imaging modalities for theevaluation of locoregional and distant sites of recurrence in breast cancer patients.Methods: From May ۲۰۱۳ to September ۲۰۱۶, ۱۰۹ patients with suspectedrecurrent breast cancer who underwent conventional imaging and F-۱۸ FDGPET/CT with an interval of ۶ weeks were consecutively enrolled (mean age: ۵۲.۶۶years; range: ۲۹-۷۹). Histopathologic results and clinical follow up based on thegold-standard imaging modality or serial imaging were considered as the referencefor verification of F-۱۸ FDG PET/CT findings.Results: Of ۱۰۹ patients, ۸۱ were found to have at least one site of recurrence(۷۴.۳۱%). Local recurrence was correctly identified in ۳۲/۳۲ patients followingPET/CT, which was higher than that on conventional imaging (۲۰/۳۲, ۶۲.۵%).PET/CT detected ۲۷ additional nodal metastases compared with conventionalimaging (۵۹ vs. ۳۲, ۴۵.۷۶%), most frequently in the hilar/mediastinal region (n=۲۷),followed by the supraclavicular lymph nodes (n=۲۰, ۶۲.۵%), internal mammarylymph nodes (n=۶, ۱۸.۷۷%), and axillary basin (n=۶, ۱۸.۷۷%). Additional sites ofdistant metastasis were identified in ۴۱ patients (۳۷.۶۱%) following F-۱۸ FDGPET/CT imaging, ۴۸.۷۸% of which were localized in the skeletal system (n=۲۰),۲۱.۹۵% in the liver (n=۹), ۱۲.۱۹% in the lungs (n=۵), ۱۲.۱۹% in the brain (n=۵), and۴.۸۷% in the adrenal glands (n=۲).Conclusion: F-۱۸ FDG PET/CT serves as a useful supplement to conventionalimaging techniques by identifying additional sites of disease recurrence in patientswith breast cancer, which may change the preferred treatment strategy, particularlyin regions that are not routinely evaluated by conventional imaging.

F-۱۸ FDG PET/CT, recurrence, breast cancer, conventional imaging