title: A multicenter prospective external validation of the diagnostic performance of IOTA simple descriptors and rules to characterize ovarian masses.
abstract: OBJECTIVE
  To evaluate the diagnostic performance of the IOTA (International Ovarian Tumor Analysis group) (clinically oriented three-step strategy for preoperative characterization of ovarian masses when ultrasonography is performed by examiners with different background training and experience.
  
  
  METHODS
  A 27-month prospective multicenter cross-sectional study was performed. 36 level II ultrasound examiners contributed in three UK hospitals. Transvaginal ultrasonography was performed using a standardized approach. Step one uses simple descriptors (SD), step two ultrasound simple rules (SR) and step three subjective assessment of ultrasound images (SA) by examiners. The final outcome was findings at surgery and the histological diagnosis of surgically removed masses.
  
  
  RESULTS
  1165 women with adnexal masses underwent transvaginal ultrasonography, 301 had surgery. Prevalence of malignancy was 31% (n=92). SD were able to classify 46% of the masses into benign or malignant (step one), with a sensitivity of 93% and specificity of 97%. Applying SD followed by SR to residual unclassified masses by SD enabled 89% of all masses (n=268) to be classified with a sensitivity 95% of and specificity of 95%. SA was then used to evaluate the rest of the masses. Compared to the risk of malignancy index (RMI), the sensitivity and specificity for the three-step (SD+SR+SA) strategy were 93% (95% CI: 86-97%) and 92% (95% CI: 87-95%) vs. 72% (95% CI: 62-80%) and 95% (95% CI: 91-97%) for RMI, respectively.
  
  
  CONCLUSIONS
  The IOTA three-step strategy shows good test performance on external validation in the hands of ultrasonography examiners with different background training and experience. This performance is considerably better than the RMI.
authors.affiliation: Department of Cancer and Surgery, Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0HS, UK.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Sayasneh
authors.forename: Jeroen
authors.initials: J
authors.lastname: Kaijser
authors.forename: Jessica
authors.initials: J
authors.lastname: Preisler
authors.forename: Susanne
authors.initials: S
authors.lastname: Johnson
authors.forename: Catriona
authors.initials: C
authors.lastname: Stalder
authors.forename: Richard
authors.initials: R
authors.lastname: Husicka
authors.forename: Sharmistha
authors.initials: S
authors.lastname: Guha
authors.forename: Osama
authors.initials: O
authors.lastname: Naji
authors.forename: Yazan
authors.initials: Y
authors.lastname: Abdallah
authors.forename: Fateh
authors.initials: F
authors.lastname: Raslan
authors.forename: Alexandra
authors.initials: A
authors.lastname: Drought
authors.forename: Alison A
authors.initials: AA
authors.lastname: Smith
authors.forename: Christina
authors.initials: C
authors.lastname: Fotopoulou
authors.forename: Sadaf
authors.initials: S
authors.lastname: Ghaem-Maghami
authors.forename: Ben
authors.initials: B
authors.lastname: Van Calster
authors.forename: Dirk
authors.initials: D
authors.lastname: Timmerman
authors.forename: Tom
authors.initials: T
authors.lastname: Bourne
mesh_terms: D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D011247:Pregnancy; D011446:Prospective Studies; D014463:Ultrasonography / Q000379:methods* / Q000592:standards*