title: Value of (18)F-FDG PET/CT in the Detection of Ovarian Malignancy.
abstract: OBJECTIVE
  Ovarian cancer is a leading cause of gynecologic malignancy. As symptoms of ovarian cancer are nonspecific, only 20 % of ovarian cancers are diagnosed while they are still limited to the ovaries. Thus, early and accurate detection of disease is important for an improved prognosis. For the accurate and effective diagnosis of ovarian malignancy on (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT), we analyzed several parameters, including visual assessment.
  
  
  METHODS
  A total of 51 peritoneal lesions in 19 patients who showed ovarian masses with diffuse peritoneal infiltration were enrolled. Twelve patients were confirmed to have ovarian malignancy and seven patients with benign disease by pathologic examination. All patients were examined by (18)F-FDG PET/CT, and an additional 2-h delayed (18)F-FDG PET/CT was also performed for 15 patients with 42 peritoneal lesions. We measured semiquantitative parameters including maximum and mean standardized uptake values (SUVmax, SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) on a 1-h initial (18)F-FDG PET/CT image (Parameter1) and on a 2-h delayed image (Parameter2). Additionally, retention indices of each parameter were calculated, and each parameter among the malignant and benign lesions was compared by Mann-Whitney U test. We also assessed the visual characteristics of each peritoneal lesion, including metabolic extent, intensity, shape, heterogeneity, and total visual score. Associations between visual grades and malignancy were analyzed using linear by linear association methods. Moreover, a receiver operating characteristic (ROC) curve was analyzed to compare the effectiveness of significant parameters.
  
  
  RESULTS
  In a comparison between the malignant and benign groups in the analysis of 51 total peritoneal lesions, SUVmax1, SUVmean1, and TLG1 showed significant differences. Also, in the analysis of 42 peritoneal lesions that underwent an additional 2-h (18)F-FDG PET/CT examination, SUVmax1,2, SUVmean1,2, TLG2, and the RI of TLG showed significant differences between the malignant and benign groups. MTV did not show significant differences in either the analysis of 51 peritoneal lesions or of 42 lesions. Regarding visual assessments, metabolic intensity, shape, heterogeneity, and total visual score showed an association with malignancy. In the ROC analysis, the AUC of the visual score was larger than the AUC of other parameters in both the analyses of 51 peritoneal lesions and of 42 lesions.
  
  
  CONCLUSIONS
  Although further study with a larger patient population is needed, the visual assessment of (18)F-FDG PET/CT imaging has a primary role in the detection of malignancy in ovarian cancer patients with assistance from other semi-quantitative parameters.
authors.affiliation: Department of Nuclear Medicine, Korea University Guro Hospital, Seoul, South Korea.
authors.forename: Taegyu
authors.initials: T
authors.lastname: Park
authors.affiliation: Department of Nuclear Medicine, Korea University Guro Hospital, Seoul, South Korea.
authors.forename: Sinae
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Korea University Guro Hospital, Seoul, South Korea.
authors.forename: Soyeon
authors.initials: S
authors.lastname: Park
authors.affiliation: Department of Nuclear Medicine, Korea University Guro Hospital, Seoul, South Korea.
authors.forename: Eunsub
authors.initials: E
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Korea University Anam Hospital, #73, Inchon-ro, Seoungbuk-gu, Seoul, 136-705 South Korea.
authors.forename: Kisoo
authors.initials: K
authors.lastname: Pahk
authors.affiliation: Department of Nuclear Medicine, Korea University Anam Hospital, #73, Inchon-ro, Seoungbuk-gu, Seoul, 136-705 South Korea.
authors.forename: Seunghong
authors.initials: S
authors.lastname: Rhee
authors.affiliation: Department of Nuclear Medicine, Korea University Anam Hospital, #73, Inchon-ro, Seoungbuk-gu, Seoul, 136-705 South Korea.
authors.forename: Jaehyuk
authors.initials: J
authors.lastname: Cho
authors.affiliation: Department of Nuclear Medicine, Korea University Ansan Hospital, Ansan, South Korea.
authors.forename: Chulhan
authors.initials: C
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, Korea University Guro Hospital, Seoul, South Korea.
authors.forename: Jae Seon
authors.initials: JS
authors.lastname: Eo
authors.affiliation: Department of Nuclear Medicine, Korea University Anam Hospital, #73, Inchon-ro, Seoungbuk-gu, Seoul, 136-705 South Korea.
authors.forename: Jae Gol
authors.initials: JG
authors.lastname: Choe
authors.affiliation: Department of Nuclear Medicine, Korea University Anam Hospital, #73, Inchon-ro, Seoungbuk-gu, Seoul, 136-705 South Korea.
authors.forename: Sungeun
authors.initials: S
authors.lastname: Kim
keywords: 18F-FDG PET/CT; Diagnostic value; Maximal standardized uptake value; Metabolic tumor volume; Ovarian cancer; Total lesion glycolysis; Visual assessment