title: Diagnostic value of PET/CT is similar to that of conventional MRI and even better for detecting small peritoneal implants in patients with recurrent ovarian cancer.
abstract: OBJECTIVE
  The aim of this study was to evaluate the diagnostic value of 2-(fluorine-18)-fluoro-2-deoxy-D-glucose ((18)F-FDG) PET/CT in comparison with MRI for the detection of recurrent ovarian cancer.
  
  
  METHODS
  Forty-seven patients with suspected ovarian cancer recurrence after total ablative or cytoreductive surgery, as well as neoadjuvant or adjuvant chemotherapy, who had undergone (18)F-FDG PET/CT imaging were recruited for the present study. All patients also underwent MRI within a month of (18)F-FDG PET/CT for the same purpose. Recurrent cancer in the abdomen and pelvis was evaluated in each of the 47 patients and classified as either distant metastasis or local pelvic recurrence involving the vaginal stump, peritoneal implants, supradiaphragmatic region, and/or abdominal and pelvic lymph nodes. Special attention was paid to peritoneal implants. These were divided into five groups according to size of the implants: less than 0.5 cm (group 1), 0.5-1 cm (group 2), 1-2 cm (group 3), 2-3 cm (group 4), and larger than 3 cm (group 5). PET/CT findings were compared with abdominopelvic MR findings. Statistical analysis was carried out using the Wilcoxon signed rank test.
  
  
  RESULTS
  Thirty-nine of 47 patients were found to have recurrent ovarian cancer. Both PET/CT and MRI were negative for recurrence in six patients. Overall sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of PET/CT were 97.5, 100, 100, 87.5, and 97.8%, respectively, whereas those of MRI were 95, 85.7, 97.4, 75, and 93.6%, respectively. For the peritoneal implants in groups 2 and 3, the sensitivity, negative predictive value, and diagnostic accuracy values of PET/CT were significantly better than those of MRI (P<0.05).
  
  
  CONCLUSIONS
  The present study revealed that PET/CT is similar to conventional MRI for the detection of recurrent ovarian cancer. PET/CT has greater accuracy in the detection of small-to-medium-sized (<2 cm) peritoneal implants compared with MRI. This may affect surgical decision making.
authors.affiliation: Department of Nuclear Medicine, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey. yaseminsanli75@yahoo.com
authors.forename: Yasemin
authors.initials: Y
authors.lastname: Sanli
authors.forename: Cuneyt
authors.initials: C
authors.lastname: Turkmen
authors.forename: Baris
authors.initials: B
authors.lastname: Bakir
authors.forename: Cem
authors.initials: C
authors.lastname: Iyibozkurt
authors.forename: Sevda
authors.initials: S
authors.lastname: Ozel
authors.forename: Duygu
authors.initials: D
authors.lastname: Has
authors.forename: Ebru
authors.initials: E
authors.lastname: Yilmaz
authors.forename: Samet
authors.initials: S
authors.lastname: Topuz
authors.forename: Ekrem
authors.initials: E
authors.lastname: Yavuz
authors.forename: Seher Nilgun
authors.initials: SN
authors.lastname: Unal
authors.forename: Ayse
authors.initials: A
authors.lastname: Mudun
mesh_terms: D000008:Abdominal Neoplasms / Q000175:diagnosis* / Q000556:secondary; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000556:secondary; D010051:Ovarian Neoplasms / Q000175:diagnosis* / Q000473:pathology; D010386:Pelvic Neoplasms / Q000175:diagnosis* / Q000556:secondary; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18