title: The performance of contrast-enhanced FDG PET/CT for the differential diagnosis of unexpected ovarian mass lesions in patients with nongynecologic cancer.
abstract: OBJECTIVE
  This study aimed to evaluate the diagnostic accuracy of contrast-enhanced FDG PET/CT for unexpected ovarian lesions in patients with nongynecologic cancers.
  
  
  METHODS
  The present retrospective study was approved by the hospital institutional review board. We enrolled 72 nongynecologic cancer patients (33 colorectal cancer, 20 breast cancer, and 19 gastric cancer) who showed unexpected ovarian lesions on contrast-enhanced FDG PET/CT and subsequently underwent surgical resection of the ovarian lesions. The SUVmax values of the ovarian lesions were compared according to the histopathological results, and the accuracy of PET/CT was evaluated.
  
  
  RESULTS
  A total of 103 ovarian lesions were surgically resected from 72 patients (64 ovarian lesions were metastases, 21 were benign, and 18 were malignant primary ovarian cancer). SUVmax among the 3 groups were different (P < 0.0001). Using a cutoff SUVmax of 2.5, the sensitivity, specificity, and accuracy of PET/CT for detecting malignant ovarian lesions were 80.5%, 81.0%, and 80.6%, respectively. Detection rates of PET/CT for colorectal, breast, and gastric cancer metastases, as well as primary ovarian cancers were 91.4%, 83.3%, 47.8%, and 100.0%, respectively. Using contrast-enhanced CT findings with SUVmax, the sensitivity, specificity, and accuracy of contrast-enhanced FDG PET/CT were improved to 95.1%, 76.2%, and 91.3%, respectively (P = 0.003).
  
  
  CONCLUSIONS
  Conventional FDG PET/CT showed moderate diagnostic accuracy for the detection of malignant ovarian lesions mainly due to low detection rate in gastric cancer metastases. The PET/CT detection rate of malignant ovarian lesions can be improved using contrast-enhanced CT findings with FDG uptake measurement.
authors.affiliation: From the *Department of Nuclear Medicine, International St. Mary's Hospital, Catholic Kwandong University College of Medicine, Incheon; †Department of Nuclear Medicine, and ‡Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Institute of Women's Life Medical Science, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Jeong Won
authors.initials: JW
authors.lastname: Lee
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Lee
authors.forename: Arthur
authors.initials: A
authors.lastname: Cho
authors.forename: Mijin
authors.initials: M
authors.lastname: Yun
authors.forename: Jong Doo
authors.initials: JD
authors.lastname: Lee
authors.forename: Young Tae
authors.initials: YT
authors.lastname: Kim
authors.forename: Won Jun
authors.initials: WJ
authors.lastname: Kang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008875:Middle Aged; D064847:Multimodal Imaging; D010051:Ovarian Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18