IOTA Simple Rules for Ovarian Mass Classification
International Ovarian Tumour Analysis (IOTA) Simple Rules classify adnexal masses as malignant (M-features), benign (B-features), or inconclusive. Applicable when using ultrasound. Sensitivity 92%, specificity 96% when applicable.
Score interpretation
Count M-features and B-features separately. Apply classification below.
→ If only M-features (no B): Malignant — refer to gynaecology oncology; CA-125 + HE4; staging CT; MDT discussion. If only B-features (no M): Benign — reassurance + surveillance ultrasound; RMI score. If both or neither: Inconclusive — specialist assessment; consider MRI; RMI calculation; expert opinion
Multiple features present — apply IOTA Simple Rules classification logic above
→ IOTA result: if exclusively M-features = malignant suspect. If exclusively B-features = benign suspect. If both or neither = inconclusive — refer to expert centre or apply IOTA ADNEX model.
Interpretation bands for the IOTA Simple Rules. Apply clinical judgement and local guidance.
References
- Timmerman D et al. Simple ultrasound-based rules for the diagnosis of ovarian cancer. Ultrasound Obstet Gynecol. 2008;31(6):681–690.
Related
Curated clinical cross-links plus same-class fallbacks.
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.