Comparison of preoperative MRI and histopathological results in local staging of endometrium cancer

Introduction-Aim: The purpose of our study is to investigate the presence and degree of myometrial invasion, the diagnostic value of the preoperative MRI in evaluating the presence of cervical invasion, and the effectiveness of tumor mean ADC values in distinguishing histopathological subtypes in patients with endometrial cancer. Material and Methods: Sixty-seven patients who were operated with the diagnosis of endometrial cancer and had lower abdominal MRI before the operation were included in our study. First, sagittal, axial T2 and sagital, axial fat-suppressed T1-weighted images in terms of presence and degree of myometrial invasion and cervical spread were evaluated and MRI' s sensitivity, specificity, positive prediction, negative prediction and accuracy values were calculated. Then, ADC measurements of 47 patients were performed by placing circular "region of interest" (ROI) to localizations that were thought to be tumor areas radiologically.Patients were divided into 3 groups histopathologically. There were 34 patients with endometrioid carcinoma in the first group, 4 patients with uterine sarcoma in the second group, and 13 patients other than endometrioid subtypes (others) in the third group. Afterwards, the relationship between the mean ADC values of the patients in groups 1 to 2 and groups 1 to 3 and histopathological types was investigated.The efficiency of tumor mean ADC values in distinguishing histopathological subtypes was statistically evaluated using the Kolmogorov Smirnov test. Results:In the non-myometrial invasion group, the sensitivity of MRI was 75%, specificity 98,41%, PPD 75%, NPD 98,41%; In the group with less than 50%(superficial) myometrial invasion, the sensitivity of MRI was 85%, specificity 92,59%, PPD 94,44%, NPD 80,65%; In the group with more than 50%(deep) myometrial invasion, the sensitivity of MRI was 95,65%, specificity 88,64%, PPD 81,48%, NPD 97,50%; The accuracy rate of MRI in determining the depth of myometrial invasion was found to be 88%. In detecting those with cervical invasion by MRI, the sensitivity was 72,73%, specificity 100%, PPD 100%, NPD 94,92%; The accuracy rate in demonstrating the presence of cervical invasion was found to be 95%. In addition, the average ADC value of the 1st group was 0.76 (± 0.12) x 10-3 mm2/s; The average ADC value of group 2 was 0.74 (± 0.35) x 10-3 mm2/s; The average ADC value of the 3rd group was 0.78 (± 0.2) x 10-3 mm2/s. When the mean ADC values of the patients in the endometrioid and sarcoma group and the patients in the endometrioid and non-endometrioid groups were compared, the p values were found to be 0.912 and 0.620, respectively, and it was not statistically significant. Conclusion: MRI examination is a highly accurate imaging method in local staging of endometrial cancers, showing the depth of myometrial invasion and the presence of cervical spread. The efficiency of tumor mean ADC values in distinguishing histopathological subtypes could not be clearly demonstrated by MRI. More comprehensive and multiparametric studies are needed on this subject. Key Words:Endometrial cancer, Myometrial invasion, Cervical invasion, Magnetic resonance imaging, Mean ADC (Apparent diffusion coefficient) value