TABLE A.III.

Risk of Malignancy Index (rmi)

rmi3,96

The rmi is a clinical prediction rule that calculates a numeric score based on the tumour marker cancer antigen 125 (CA125), which may be elevated in the blood of some cancer patients, multiplied by a menopausal score (M) and an ultrasonography-based morphology score (U). The most common threshold for probability of malignancy is 200. Scores are calculated as follows: $$\text{RMI}=\text{U}\times \text{M}\times \text{CA}125$$   where U is 0, 1, or 3 (see explanation, next); M is 1 (premenopausal) or 3 (postmenopausal); and CA125 is the serum CA125 in units per millilitre.

The transabdominal ultrasound imaging is scored 1 point for each of these characteristics: Multilocular cyst Evidence of solid areas Evidence of metastases Presence of ascites Bilateral lesions

If the score is 0, then U = 0; if the score is 1, then U = 1; if the score is 2 or more, then U = 3.

rmi297

The rmi2 is calculated in the same way as the original rmi, except that the U and M components are differently weighted: M is 1 (premenopausal) or 4 (postmenopausal). If the transabdominal ultrasound imaging score is 0 or 1, then U = 1; if the score is 2 or more, then U = 4.

rmi398

The rmi3 further refines the rmi and rmi2, using the same definitions, but adjusting the U and M components: M is 1 (premenopausal) or 3 (postmenopausal). If the transabdominal ultrasound imaging score is 0 or 1, then U = 1; if the score is 2 or more, then U = 3.