title: Integrated FDG-PET/CT imaging is useful in the approach to carcinoid tumors of the lung.
abstract: BACKGROUND
  Carcinoids enter the differential diagnosis of the solitary pulmonary nodule. Bronchial carcinoids have been traditionally considered as FDG-PET negative but recent studies have found an higher sensitivity of integrated FDG-PET/CT for the detection of these neoplasms. The purpose of this study was to investigate the value of integrated FDG-PET/CT for the evaluation of SPN suspected to be carcinoids.
  
  
  METHODS
  All patients with pathologically proven bronchial carcinoids who had FDG-PET/CT scans between 2006 and 2012 have been retrospectively reviewed. PET/CT was performed with the same scanner and the same technique for all patients. The following data were retrieved: age, sex CT findings (side, location, size, shape, margins), SUVmax, type of operation, pathological findings (size and number of mitoses). Regarding PET findings, only SUVmax was considered, whereas the visual assessment was not undertaken. Carcinoids were defined as typical and atypical and as central and peripheral. The long-term follow-up was also recorded. The SUVmax was compared with the other clinical, radiological and pathological variables to find any significant difference or correlation.
  
  
  RESULTS
  Twenty-five patients were retrieved, 24 typical and one atypical carcinoid, 21 peripheral and 4 central lesions. The mean diameter on CT-scan was 25.3 mm and the clinical size correlated well with the pathological size. Sixty percent of the tumors were ovoid and 68% had smooth margins. The mean SUVmax was 3.6 (range 1.4-12.9). All the lesions were completely resected. The regression analysis showed a direct correlation between the SUVmax and the tumor size (p = 0.004). No further correlations were found between the SUVmax and the other variables. None of the patients had recurrent disease or died during the follow-up.
  
  
  CONCLUSIONS
  Our study showed that FDG-PET/CT might be a useful tool in the evaluation of SPNs suspected to be bronchial carcinoids. When a solitary pulmonary nodule shows an ovoid/round shape and smooth margins on the CT scan and demonstrates an FDG uptake higher than that of the normal lung and with a SUVmax value >1-1.5, a carcinoid should be suspected. If benign lesions can be presumably excluded, surgical resection or at least a biopsy of the lesion is recommended.
authors.affiliation: Department of Thoracic Surgery, University of Modena and Reggio Emilia, Modena, Italy. alessandro.stefani@unimore.it.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Stefani
authors.forename: Antonella
authors.initials: A
authors.lastname: Franceschetto
authors.forename: Jessica
authors.initials: J
authors.lastname: Nesci
authors.forename: Beatrice
authors.initials: B
authors.lastname: Aramini
authors.forename: Chiara
authors.initials: C
authors.lastname: Proli
authors.forename: Shaniko
authors.initials: S
authors.lastname: Kaleci
authors.forename: Alessandra
authors.initials: A
authors.lastname: Casolo
authors.forename: Lucia
authors.initials: L
authors.lastname: Massi
authors.forename: Christian
authors.initials: C
authors.lastname: Casali
authors.forename: Uliano
authors.initials: U
authors.lastname: Morandi
mesh_terms: D000328:Adult; D000368:Aged; D001984:Bronchial Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D002276:Carcinoid Tumor / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D012044:Regression Analysis; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18