title: The role of the breast radiologist in evaluation of breast incidentalomas detected on 18-fludeoxyglucose positron emission tomography/CT.
abstract: OBJECTIVE
  To evaluate the significance of incidentally discovered breast lesions on 18-fludeoxyglucose ((18)F-FDG) positron emission tomography (PET)/CT.
  
  
  METHODS
  6050 (18)F-FDG PET/CT studies, performed between January 2009 and February 2012, were retrospectively reviewed. 55 lesions in 50 patients were identified. Additional work-up, including mammography, ultrasound, follow-up (18)F-FDG PET/CT and biopsy, was available for 39 incidental breast lesions in 36 patients. All patients were female, with mean age 61.5 years (range 36-90 years). The maximum standardised uptake value (SUVmax), CT size and CT Breast Imaging Reporting and Data System (BI-RADS®) scores were compared between the malignant and the benign subgroups, using the unpaired t-test and Fisher's exact test. Tests were two-sided and a p-value of <0.05 was considered to be significant.
  
  
  RESULTS
  Incidental breast lesions were identified in 50 (0.8%) of 6050 (18)F-FDG PET/CT studies. 21 (53.8%) of the 39 breast incidentalomas were malignant on biopsy or imaging, of which 15 (38.5%) represented a second primary breast cancer. A statistically significant difference in the mean SUVmax between malignant and benign breast lesions was observed (p=0.021). Malignancy was significantly more common in the CT BI-RADS Category 4 or greater groups (76.2%; p=0.0105).
  
  
  CONCLUSIONS
  Incidental breast lesions detected at (18)F-FDG PET/CT are uncommon. When detected, however, they may represent malignancy in up to 53.8% of cases.
  
  
  CONCLUSIONS
  SUVmax and CT findings at (18)F-FDG PET/CT can assist with differentiating benign and malignant breast conditions, guiding further evaluation with dedicated breast imaging. Review of (18)F-FDG PET/CT-detected breast lesions by a breast radiologist may be helpful in determining the need for and correlation with further breast imaging. Radiologists and nuclear medicine physicians should be cognisant of breast pathology when reporting (18)F-FDG PET/CT image data sets.
authors.affiliation: Department of Radiology, St. James's Hospital, Dublin 8, Ireland. ruthdunne@yahoo.co.uk
authors.forename: R M
authors.initials: RM
authors.lastname: Dunne
authors.forename: D
authors.initials: D
authors.lastname: O'Mahony
authors.forename: G
authors.initials: G
authors.lastname: Wilson
authors.forename: R
authors.initials: R
authors.lastname: McDermott
authors.forename: S A
authors.initials: SA
authors.lastname: O'Keeffe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D033162:Incidental Findings; D007822:Laryngeal Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary; D008327:Mammography / Q000379:methods; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary; D016217:Ultrasonography, Mammary
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18