Indeterminate Ovarian Mass at US: Incremental Value of Second Imaging Test for Characterization—Meta-Analysis and Bayesian Analysis

Abstract

To compare value of current diagnostic strategies in assessment of changes in posttest probability of ovarian cancer when menopausal status and combination and sequence of diagnostic imaging tests are considered. Prevalence of ovarian cancer according to menopausal status in women with an ovarian mass and performance of combined gray-scale and Doppler ultrasonography (US), computed tomography (CT), and non-enhanced magnetic resonance (MR) imaging and contrast material-enhanced MR imaging after indeterminate results at gray-scale US were derived from meta-analysis by using MEDLINE database and institutional data. Study was approved by the institutional review board of University Hospital Geneva, Geneva, Switzerland; informed consent was waived. Posttest probability values were computed through Bayesian analysis and Monte Carlo simulation after initial gray-scale US and secondary combined gray-scale and Doppler US, CT, or MR imaging, while dependence of test results among imaging modalities was considered. Changes in posttest probability were compared among imaging modalities with summary receiver operating characteristic curves. Prevalence of ovarian cancer was 8.75% in premenopausal women and 32.40% in postmenopausal women with an ovarian mass. After characterization with initial gray-scale US, posttest probability in pre- and postmenopausal women changed, respectively, to 25% and 63% for indeterminate results and to 2% and 7% for benign results. Subsequent use of combined gray-scale and Doppler US, CT, or MR imaging had significant higher positive and lower negative posttest probability than did use of gray-scale US alone. In women with an indeterminate initial US result, posttest probability decreased after secondary testing with benign results for all imaging modalities to 2% in premenopausal women and to 8%-10% in postmenopausal women. After secondary testing for suspicious lesions, posttest probability increased more after non-enhanced (premenopausal women, 70%; postmenopausal women, 92%) or contrast-enhanced MR imaging (premenopausal women, 80%; postmenopausal women, 95%) than it did after combined gray-scale and Doppler US (premenopausal women, 30%; postmenopausal women, 69%) or CT (premenopausal women, 38%; postmenopausal women, 76%) (P < .001). In women with an indeterminate ovarian mass at gray-scale US, MR imaging results contributed to change in probability of ovarian cancer in both pre- and postmenopausal women more than did CT or combined gray-scale and Doppler US results.