Table 1. Description of the IOTA methods evaluated in the IOTA study phase 3.
| IOTA method | Variables or features |
|---|---|
| LR1 10 (risks ⩾10% indicate malignancy) |
(1) Personal history of ovarian cancer (yes, 1; no, 0), (2) current use of hormonal therapy (yes, 1; no, 0), (3) age of the patient (in years), (4) maximum diameter of lesion (in mm), (5) tender mass at examination (yes, 1; no, 0), (6) ascites (yes, 1; no, 0), (7) blood flow in papillary projection (yes, 1; no, 0), (8) purely solid tumour, (9) maximum diameter of the largest solid component (in mm, but with no increase >50 mm), (10) irregular internal cyst walls (yes, 1; no, 0), (11) acoustic shadows (yes, 1; no, 0), and (12) colour flow score (1–4, where 1 is no flow and 4 is maximum flow).
The mathematical formula is presented in Supplementary Appendix. |
| LR210, (risks ⩾10% indicate malignancy) |
(1) Ascites (yes, 1; no, 0), (2) blood flow in papillary projection (yes, 1; no, 0), (3) maximum diameter of the largest solid component (in mm, but with no increase >50 mm), (4) irregular internal cyst walls (yes, 1; no, 0), (5) acoustic shadows (yes, 1; no, 0), (6) age of the patient (in years).
The mathematical formula is presented in Supplementary Appendix. |
| IOTA SRs11,a |
Benign features: unilocular tumour (B1), largest diameter of largest solid component <7 mm (B2), acoustic shadows (B3), smooth multilocular tumour with largest diameter <100 mm (B4), no intratumoural blood flow at colour or power Doppler (B5).
Malignant features: irregular solid tumour (M1), ascites (M2), At least four papillary projections (M3), irregular multilocular solid tumour with largest diameter ⩾100 mm (M4), very strong intratumoural blood flow at colour or power Doppler (M5). |
| IOTA SDs12,b | Benign descriptors: unilocular tumour with ground glass echogenicity in a premenopausal woman; unilocular tumour with mixed echogenicity and acoustic shadows in a premenopausal woman; unilocular anechoic tumour with regular walls and maximum diameter of lesion<10 cm; remaining unilocular tumours with regular walls. Malignant descriptor: tumour with ascites and at least moderate colour Doppler blood flow in a postmenopausal woman; age >50 years and CA-125 >100 U ml–1. |
Abbreviations: IOTA=international ovarian tumour analysis; LR1=logistic regression model 1; LR2=logistic regression model 2; SDs=simple descriptors; SR=simple rules.
A mass is classified as malignant if at least one M-feature and none of the B-features are present and vice versa. If no B or M features are present, or if both B and M features are present, then the rules are considered inconclusive (unclassifiable mass), and a second stage test should be used in the unclassifiable tumours.
A mass classified as malignant if at least one malignant descriptor and none of the benign descriptors are present and vice versa. If no benign or malignant descriptors are present, or if both benign and malignant descriptors are present, then the descriptors are inconclusive (unclassifiable mass), and a second stage test should be used in the unclassifiable tumours.