IOTA Simple Rules (Adnexal Mass)
IOTA Simple Rules (Timmerman 2008; validated BMJ 2010)Applies the ten IOTA Simple Rules — five benign (B1–B5) and five malignant (M1–M5) ultrasound features — to classify an adnexal mass as benign, malignant, or inconclusive, with guidance on second-stage testing for inconclusive masses.
Also searched as: ovary · ultrasound · doppler · gynecology · ovarian
Information
Incomplete input
- The following information is still needed: assessment of: B1 — unilocular cyst, B2 — solid component(s), largest <7 mm, B3 — acoustic shadows, B4 — smooth multilocular tumor <100 mm, B5 — no blood flow (color score 1), M1 — irregular solid tumor, M2 — ascites, M3 — at least four papillary structures, M4 — irregular multilocular-solid tumor ≥100 mm, M5 — very strong blood flow (color score 4).
How this tool works
The IOTA Simple Rules (Timmerman et al., 2008; prospectively validated in BMJ 2010) are a triage tool for adnexal masses based on ten sonographic features. Benign features are a unilocular cyst (B1), solid components whose largest measures under 7 mm (B2), acoustic shadows (B3), a smooth multilocular tumor under 100 mm (B4), and absent Doppler flow, i.e. color score 1 (B5). Malignant features are an irregular solid tumor (M1), ascites (M2), at least four papillary structures (M3), an irregular multilocular-solid tumor of 100 mm or more (M4), and very strong Doppler flow, i.e. color score 4 (M5). A mass with only B features is classified benign; a mass with only M features is classified malignant; a mass showing both kinds of features, or none, is inconclusive and requires a second-stage test (expert subjective assessment or a risk model such as IOTA ADNEX). When conclusive, the rules achieved about 92% sensitivity and 96% specificity in the 2010 multicenter validation, and they apply to roughly three quarters of masses. The related Simple Rules Risk Assessment (2016) embeds the same features plus an oncology-center variable in a logistic model that returns a numerical malignancy risk, including for rule-inconclusive masses; that variant is not computed here.
References
- Timmerman D, et al. Simple ultrasound rules to distinguish between benign and malignant adnexal masses before surgery: prospective validation by IOTA group. BMJ 2010;341:c6839
- Garg S, et al. Evaluation of IOTA Simple Ultrasound Rules (feature definitions and pooled validation table), J Clin Diagn Res 2017
- Evaluation of Adnexal Masses: The IOTA Concept (Thieme review; SR risk assessment context)
Implemented from the cited published sources. Educational use only; confirm against current guidelines before clinical use.
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