Preoperative imaging in patients undergoing trachelectomy for cervical cancer: Validation of a combined T2- and diffusion-weighted endovaginal MRI technique at 3.0 T

•High spatial resolution endovaginal MRI of the cervix in patients potentially selected for trachelectomy•Correlation of MRI with histopathology in subcentimetre cervical tumours•Interobserver comparison of measured tumour maximum dimension and volume on endovaginal MRI

AimThe aim of this study is to validate high-resolution endovaginal T2- and diffusion-weighted MRI measurements (tumour size, volume and length of uninvolved cervical canal) against histology in patients undergoing trachelectomy.Patients/interventions55 consecutive patients 25-44 years with cervical cancer being considered for trachelectomy were prospectively assessed with endovaginal T2-W and diffusion-weighted MRI. Two independent observers blinded to histology recorded maximum tumour dimension, volume and distance from the superior aspect of the tumour to the internal os. Following trachelectomy, pathologist-outlined tumour sections were photographed with a set scale and similar measurements were recorded.ResultsFifteen of 45 patients subsequently treated with fertility-sparing surgery had residual tumour (median histological volume: 0.28 cm3, IQR = 0.14-1.06 cm3). Sensitivity, specificity, positive and negative predictive values for detecting tumour: Observer1: 86.7%, 80.0%, 68.4%, and 92.3%, respectively; Observer2: 86.7%, 90.0%, 81.0%, and 93.1%, respectively. Size and volume correlated between observers (r = 0.96, 0.84, respectively, p < 0.0001). Size correlated between each observer and histology (observer 1 r = 0.91, p < 0.0001; observer 2 r = 0.93, p < 0.0001), volume did not (observer 1: r = 0.08, p = 0.6; observer 2: r = 0.21, p = 0.16); however, differences between observer measurements and histology were not significant (size p = 0.09, volume p = 0.15). Differences between MRI and histology estimates of endocervical canal length were not significant (p = 0.1 both observers).ConclusionIn subcentimetre cervical cancers, endovaginal MRI correlates with pathology and is invaluable in assessing patients for fertility-sparing surgery.