Comparison Of RMI And GI-RADS Ultrasonographic Stratification In Differentiating Benign From Malignant Adnexal Masses

Objective To compare the risk of malignancy index(RMI) with gynecologic imaging reporting with data system(GI-RADS) classification in differentiating benign from malignant adnexal masses. Methods A retrospective analysis was conducted on342 patients who were underwent surgery or received interventional treatment after ultrasonographic diagnosis of adnexal masses at the Second Affiliated Hospital of Fujian Medical University from January 2012 to December 2015. If GI-RADS 1~ 4b was considered as benign, GI-RADS 5 as malignant, defined as GI-RADS-1. If GIRADS 1~ 4a was considered as benign,GI-RADS 4b~5 as malignant, defined as GIRADS-2. If GI-RADS 1 ~ 3 was considered as benign, GI-RADS 4a~5 as malignant,defined as GI-RADS-3. Taking RMI1,RMI2,RMI3 = 200 and RMI4= 450 as critical points and using GI-RADS-1,GI-RADS-2, GI-RADS-3 to differentiate benign from malignant respectively, the sensitivity, specificity, positive predictive value(PPV),negative predictive value(NPV) and area under the curve(AUC) were calculated for GI-RADS and RMI compared with gold standard(pathology diagnoses).Results(1)Taking RMI1, RMI2, RMI3 = 200 and RMI4 = 450 as critical points, the sensitivity were 50.51%, 52.53%, 50.51%, 53.54%, respectively, specificity were 95.47% in common, PPV were 81.97%, 82.54%, 81.97%, 82.81%, respectively, and NPV were82.56%, 83.15%, 82.56%, 83.45% respectively. RMI1, RMI2, RMI3, RMI4 had no statistically significant difference(p>0.05).(2)When using GI-RADS-1, GI-RADS-2,GI-RADS-3, the sensitivity were 38.38%, 70.71%, 89.90%, respectively, specificity were 99.59%, 98.77%, 67.90%, respectively, PPV were 97.44%, 95.89%, 53.29%,respectively, and NPV were 79.87%, 89.21%, 94.29%, respectively, respectively. GIRADS-1, GI-RADS-2 and GI-RADS-3 had statistically significant difference(p<0.05).(3)RMI4 and GI-RADS-2 had statistically significant difference(z=2.97, P=0.003),which AUC were 0.903, 0.813 respectively. Conclusions(1)RMI1, RMI2, RMI3, RMI4 had the same value in differentiating benign from malignant adnexal masses.(2)GIRADS-2 was thought to be most accurately among the three definition predictive method of GI-RADS.(3)GI-RADS-2 was found to be more accurately than RMI4.