Diagnostic Accuracy of Magnetic Resonance Imaging in Endometrial Cancer

Accuracy of MRI in predicting deep myometrial invasion in endometrial cancer and the influence of leiomyoma, adenomyosis and the microcystic elongated and fragmented tumour pattern

INTRODUCTION

The most common form of endometrial cancer is Type 1 endometrioid adenocarcinoma. Depth of myometrial invasion is the most important prognostic factor correlating with overall patient survival. The objective was to investigate how accurate magnetic resonance imaging (MRI) is in predicting the depth of myometrial invasion in preoperative assessment, and the influence of leiomyoma and/or adenomyosis, or microcystic, elongated and fragmented (MELF) pattern of invasion on MRI diagnostic performance.

METHOD

Retrospective audit of 235 endometrial cancer patients from the regional Gynaecology Oncology multidisciplinary meeting at Auckland City Hospital, between January 2020 and January 2021. Radiologist assigned stage was compared to histopathology. Presence of leiomyoma, adenomyosis and MELF pattern evaluated followed by analysis under a Biostatistician's supervision.

RESULTS

Overall MRI diagnostic accuracy for depth of myometrial invasion was 86%. For deep myometrial invasion, MRI had a sensitivity of 72% and specificity 91%. Out of the misreported 32/235 cases, 16 demonstrated fibroids and/or adenomyosis leading to a sensitivity of 57% and specificity 93% for deep invasion, compared with 94% and 74% respectively in the population without, demonstrating statistical significance. Thirty seven cases with MELF pattern of invasion showed a sensitivity of 81% and specificity 80% for deep invasion, compared with 63% and 92% respectively in the group without, demonstrating no statistical significance.

CONCLUSION

MRI assessment of the depth of myometrial invasion in endometrial cancer has high accuracy. In the presence of background uterine fibroids/adenomyosis, pre-operative MRI accuracy of evaluating deep invasion shows a statistically significant reduction.

Preoperative magnetic resonance imaging predicts clinicopathological parameters and stages of endometrial carcinomas

BACKGROUND

We investigated the agreement and accuracy of preoperative magnetic resonance imaging (MRI) with postoperative pathological characteristics and stages of endometrial endometrioid carcinoma (EEC).

METHODS

We recruited 527 women with EEC who underwent staging surgery at a single medical institution. The preoperative MRI, stages, and clinical and pathological parameters, including myometrial invasion (MI), cervical invasion (CI), adnexal metastasis (AM), intra-abdominal metastasis, and pelvic and/or para-aortic nodal metastasis, were recorded and analyzed. The agreement and accuracy between the preoperative MRI findings and these parameters and stages were assessed.

RESULTS

The rate of the preoperative MRI-based clinical stage matching the postoperative surgical stage was 85.2% in International Federation of Gynecology and Obstetrics stage IA, 51.9% in stage IB, 35.5% in stage II, 5.3% in stage IIIA, 33.3% in stage IIIB, 28.6% in stage IIIC1, 64.3% in stage IIIC2, and 93.8% in stage IVB. The consistency between radiologists and pathologists was 80.5% for deep MI, 91.5% for cervical invasion, 92.2% for adnexal metastasis, 98.9% for intra-abdominal metastasis, and 87.5% and 92.2% for pelvic and para-aortic nodal metastases, respectively. The negative predictive value of intra-abdominal metastasis was the highest with 99.8%.

CONCLUSIONS

Preoperative MRI could be an excellent tool for routine preoperative assessment to predict pathological parameters and stages of EEC, especially in excluding intra-abdominal metastatic disease.

Diagnostic Accuracy in Assessment of Depth of Myometrial Invasion in Low-grade Endometrioid Carcinoma: A 2 Center Comparative Study by MRI and Intraoperative Assessment

The role of lymphadenectomy in endometrial carcinomas is controversial, especially in low-grade endometrioid carcinomas. In many institutions, lymphadenectomy in the latter neoplasms is undertaken only when there is deep myometrial invasion, defined as invasion involving 50% or more of the myometrium (FIGO stage IB). There has been considerable debate as to the best modality to detect deep myometrial invasion. In Europe, preoperative magnetic resonance imaging (MRI) is the most commonly used modality while in North America, intraoperative assessment (IOA) is undertaken in most, but not all, institutions. The aim of this study was to compare the diagnostic accuracy of these 2 modalities in identifying deep myometrial invasion in low-grade endometrioid carcinomas. Two patient cohorts were studied from Belfast, UK (n=253) and Boston, USA (n=276). With respect to detecting deep myometrial invasion, MRI had a sensitivity of 72.84%, positive predictive value of 75.64% and a positive likelihood ratio of 6.59 (95% confidence interval; 4.23-10.28). IOA had a sensitivity of 78.26%, positive predictive value of 80% and a positive likelihood ratio of 20.00 (95% confidence interval; 10.35-38.63). The superior positive likelihood ratio suggests that IOA is better than MRI in determining deep myometrial invasion and the nonoverlapping 95% confidence intervals suggest this is a significant finding. However, there are significant resource implications associated with IOA and preoperative MRI carries other advantages that are discussed herein.

ACR Appropriateness Criteria® Abnormal Uterine Bleeding

This publication summarizes the relevant literature for the imaging of patients with symptoms of abnormal uterine bleeding, including initial imaging, follow-up imaging when the original ultrasound is inconclusive, and follow-up imaging when surveillance is appropriate. For patients with abnormal uterine bleeding, combined transabdominal and transvaginal ultrasound of the pelvis with Doppler is the most appropriate initial imaging study. If the uterus is incompletely visualized with the initial ultrasou2nd, MRI of the pelvis without and with contrast is the next appropriate imaging study, unless a polyp is suspected on the original ultrasound, then sonohysterography can be performed. If the patient continues to experience abnormal uterine bleeding, assessment with ultrasound of the pelvis, sonohysterography, and MRI of the pelvis without and with contrast would be appropriate. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

The value of MRI in management of endometrial hyperplasia with atypia

Background

The value of the magnetic resonance imaging (MRI) in the assessment of women with endometrial hyperplasia and its role in diagnosis of myometrial invasion or coexistence of cancer is not known. This study aimed to evaluate the accuracy and usefulness of MRI in the management of patients diagnosed on endometrial biopsy with complex endometrial hyperplasia with atypia (CEHA).

Methods

A retrospective study of 86 cases diagnosed with endometrial hyperplasia with atypia on the initial endometrial biopsy in a tertiary university teaching hospital between 2010 and 2015 was carried out. The MRI accuracy in predicting malignant changes and influence the clinical management was compared among women who had either pelvic MRI, transvaginal ultrasound (TVUS), or no additional imagistic studies.

Results

MRI was performed in 24 (28%) and TVUS in 11 (13%)cases, while 51 (59%) women had no additional imagistic studies. In the group of women with no imaging studies, 26/51 (51%) were surgically treated and 8/26 (31%) were diagnosed with endometrial cancer (EEC) stage 1a. In the group of women who had TVUS, 5/11 (45%) were surgically treated and none was diagnosed with EEC. In the group of women who underwent an MRI examination, 20/24 (83%) were surgically treated. Among these, 11/20 (55%) were diagnosed with EEC, 7 had EEC stage 1a, and 4 had EEC stage 1b. Although MRI was able to identify malignant changes with a good sensitivity (91.7%), it had a low specificity in characterisation of malignant transformation (8%). MRI correctly identified 31% of the stage 1a and 33% of the stage 1b endometrial cancer.

Conclusion

In this study, we found a potential diagnostic value of MRI for identifying malignant transformation in patients with CEHA. However, pelvic MRI has a rather weak predictive value of myometrial invasion in women with CEHA and concurrent EEC. The diagnostic and therapeutic benefits of MRI assessment in patients with CEHA need further validation.

A Prospective Observational Study Evaluating the Accuracy of MRI in Predicting the Extent of Disease in Endometrial Cancer

This prospective study looks into the accuracy of magnetic resonance imaging (MRI) in predicting the depth of MI, cervical invasion, lymph node metastasis, and extrauterine spread (EUS) of disease in endometrial cancer. Between June 2014 and December 2015, 58 patients with biopsy-proven endometrial cancer who underwent MRI prior to surgery were included in the study. MRI findings like myometrial invasion, extrauterine spread, lymph nodal metastasis, and cervical invasion were compared against the histopathology report. Sensitivity, specificity, PPV, NPV, and overall accuracy of MRI for myometrial depth assessment were 75.0%, 73.08%, 77.2%, 70.37%, and 74.14 respectively. Sensitivity, specificity, PPV, NPV, and overall accuracy of MRI in assessing lymph node spread were 88.64%, 66.67%, 95.12%, 44.44%, and 86.0% respectively. As for predicting extrauterine spread and cervical invasion, MRI showed poor sensitivity (37.5% and 50% respectively) and a high specificity (92% and 100% respectively). Our study shows that preoperative MRI has high sensitivity and specificity to predict myometrial invasion and lymph node involvement. But, it is not sensitive enough to predict cervical involvement or extrauterine spread.

Assessment of Myometrial Invasion in Premenopausal Grade 1 Endometrial Carcinoma: Is Magnetic Resonance Imaging a Reliable Tool in Selecting Patients for Fertility-Preserving Therapy?

OBJECTIVES

The aim of this study was to evaluate the diagnostic ability of magnetic resonance imaging (MRI) in premenopausal women with G1 endometrial carcinoma.

METHODS

Twenty-six patients underwent T2W, diffusion weighted, and dynamic contrast-enhanced 3-T MRI. The degree of myometrial invasion was pathologically classified into no invasion, shallow (3 mm or less), and more. Two radiologists assessed myometrial invasion on MRI. Diagnostic accuracy, sensitivity, specificity, positive and negative predictive values, AUC, and interobserver agreement were analyzed.

RESULTS

For assessing myometrial invasion, mean accuracy, sensitivity, specificity, positive predictive values, negative predictive values, and AUC, respectively, were as follows: 63%, 42%, 85%, 79%, 47%, and 0.75. Mean interobserver agreement was fair (k = 0.36). Shallow invasions were underestimated as no invasion on MRI in all 6 cases.

CONCLUSIONS

Magnetic resonance imaging produced false-negative result on half of patients. The misjudgments tended to happen in patients with shallow invasion.

[Pertinence of the preoperative exploration in the evaluation of the risk of lymph node metastasis in endometrial cancer]

PURPOSE

To assess the relevance of MRI, endometrial biopsy and curettage in the diagnosis of endometrial cancer at high risk of lymph node metastasis.

PATIENTS AND METHODS

A retrospective study on continuous series of patients treated for endometrial cancer limited to the uterus between 2004 and 2008, results of preoperative evaluation of tumor stage using MRI, histological type and grade by endometrial curettage and biopsies were compared to final histological examination.

RESULTS

One hundred and sixty-nine patients were included in the study. Ninety (53.3%) had MRI, 112 (66.2%) curettage and 61 (36.6%) endometrial biopsy using Pipelle de Cornier. Sensibility (SN), specificity (SP), positive (PPV) and negative predictive values (NPV) of MRI, in the diagnosis of endometrial cancer at high risk of lymph nodes metastases were of 65.6%, 87.2%, 77.7%, 79.2%. For EB and curettage SN, SP, PPV and NPV were of 42.9%, 96.9%, 85%, 79.5%; 80.6%, 98.3%, 96.2% and 90.6% respectively. 37.8% of cancers diagnosed to be at low risk of lymph node metastasis were at high risk in definitive histologic examination.

DISCUSSION AND CONCLUSION

Preoperative evaluation by MRI, endometrial curettage and biopsy has good diagnostic value in the identification of endometrial cancer susceptible to benefit from lymphadenectomy. Underestimation, however, is encountered in approximately one third of cases.

Prediction of lymph node and distant metastasis in patients with endometrial carcinoma: a new model based on demographics, biochemical factors, and tumor histology

OBJECTIVE

To develop a model that might predict the probability of lymph node and distant metastasis (stages IIIC-IV) in endometrial carcinoma.

METHODS

We studied 774 patients with endometrial carcinoma treated in a single institution. Demographic factors, biochemical factors and preoperative tumor characteristics, identified as potential risk factors for advanced carcinoma in unadjusted analyses, were used to create a logistic regression model with lymph node and distant metastasis as the dependent variable. Statistically significant odds ratios in the regression model were rounded to the nearest whole number. These rounded values were the estimated weights for each factor that were summed to generate a score that might predict the probability of stage IIIC-IV carcinoma.

RESULTS

Biochemical factors and preoperative tumor characteristics predicted lymph node and distant metastasis in the regression model, whereas demographic factors were without effect. The score combining weighted risk factors was: (2 × leukocytosis)+(3 × thrombocytosis)+(7 × elevated CA125)+(4 × high-risk histology). The area under curve (AUC) for this total score was 0.823, with 71.6% sensitivity, 75.2% specificity, 25.9% positive predictive value, and 95.7% negative predictive value, using 6 as cut-point. After excluding stage IV carcinomas from the dataset, the AUC was 0.813 for the total score in predicting nodal involvement (P=0.82 vs. total score in predicting stage IIIC-IV carcinomas in the complete dataset).

CONCLUSIONS

Based on the high negative predictive value, this prediction model could be applied for identifying patients who may not benefit from lymphadenectomy for endometrial carcinoma staging.