Clinical stage I endometrial carcinoma: pitfalls in preoperative assessment with MR imaging. Work in progress

Diagnostic Performance of Preoperative Imaging in Endometrial Cancer

BACKGROUND

Endometrial cancer is one of the most common gynecological malignancies. Because the findings mentioned in radiogram interpretation reports issued by diagnostic radiologists influence treatment strategies, we aimed to evaluate the diagnostic accuracy of preoperative computed tomography (CT) and magnetic resonance imaging (MRI) interpretation results in clinically relevant settings.

METHODS

The clinical records of patients diagnosed with endometrial cancer treated at Tohoku University Hospital from January 2012 to December 2021 were reviewed. The preoperative and pathologically estimated cancer stages were compared based on the results mentioned in the radiogram interpretation report.

RESULTS

The preoperative and postoperative cancer stages were concordant in 70.0% of the patients. By contrast, the cancer stage was underdiagnosed and overdiagnosed in 21.7% and 8.2% of the patients, respectively. The sensitivities of MRI for deep myometrial invasion, cervical stromal invasion, vaginal invasion, and adnexal metastasis were 65.1%, 58.2%, 33.3%, and 18.4%, respectively. The sensitivity and specificity for pelvic lymph node metastasis using a combination of CT and MRI were 40.9% and 98.4%, respectively. Those for para-aortic lymph node metastases using CT were 37.0% and 99.5%, respectively.

CONCLUSIONS

The low sensitivity observed in this study clarified the limitations of preoperative diagnostic performance in current clinical practice.

Magnetic resonance imaging pitfalls in determining myometrial invasion in stage I endometrial cancer: A case report and literature review

The degree of myometrial invasion (MI) is crucial in the preoperative diagnosis of endometrial cancer (EC) using MRI in terms of therapeutic and prognostic implications. However, several pitfalls should be kept in mind when using this modality. We report a case of EC on a 64-year-old woman, identified preoperatively without MI based on ultrasonography and MRI, implying a low risk of lymph node metastasis; surprisingly, the uterine incision showed the lesion had invaded <50% of the myometrium. Thus, a total laparoscopic hysterectomy and bilateral salpingo-oophorectomy were performed, and histopathologic analysis confirmed that the EC was on stage IA (cancer is in the endometrium only or less than halfway through the myometrium). In our case, thinning myometrium and uterine atrophy due to aging, multiple leiomyomas, previous curettage, and blood clots were all pitfalls for MRI in detecting MI. By detecting tiny or isointense tumors and depicting distinct vascularity of the malignancy in postmenopausal women, functional MRI techniques such as diffusion-weighted imaging (DWI) and dynamic contrast-enhanced MRI (DCE-MRI) can help reduce pitfalls when assessing MI. Clinicians can employ DWI preoperatively, which is more reliable and superior to DCE-MRI in determining tumor areas without contrast injection and perform a postoperative histopathological examination to confirm MI in EC.

Peritumoral Enhancement for the Evaluation of Myometrial Invasion in Low-Risk Endometrial Carcinoma on Dynamic Contrast-Enhanced MRI

Objectives

To explore the clinical value of subendometrial enhancement (SEE), irregular thin-layered peritumoral early enhancement (ITLPE) and focal irregular peritumoral early enhancement (FIPE) on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for myometrial invasion in patients with low-risk endometrial carcinoma.

Methods

Seventy-seven patients with low-risk endometrial carcinoma who preoperatively underwent DCE-MRI were included. Two radiologists independently evaluated and recorded the occurrences of SEE, ITLPE and FIPE on DCE-MRI in all patients. Interobserver agreement was calculated between the two radiologists, and the relationships between SEE, ITLPE, FIPE, and myometrial invasion were analyzed based on histologic findings. For statistically significant findings, the sensitivity and specificity were calculated, and the differences in myometrial invasion evaluations were analyzed. For those with no statistical significance, images were compared with the histopathologic sections.

Results

Inter-observer agreement was good (k = 0.80; 95%CI, 0.577–0.955) for SEE, and very good (k = 0.88; 95%CI, 0.761–0.972) (k = 0.86; 95%CI, 0.739–0.973) for ITLPE and FIPE. After consensus, SEE was identified in 12/77 (15.6%) patients; ITLPE and FIPE were found in 53/77 (68.8%) and 30/77 (39.0%) patients, respectively. SEE and ITLPE were significantly correlated with myometrial infiltration (P = 0.000), but FIPE were not (P = 0.725).The sensitivity and specificity of SEE and ITLPE for myometrial invasion in patients with low-risk endometrial carcinoma were 95.0 and 52.9%, and 85.0 and 88.0%, respectively. The area under the curve (AUC) of SEE and ITLPE for myometrial invasion were 0.740 (95%CI, 0.584–0.896), and 0.866 (95%CI, 0.763–0.970), respectively. The sensitivity and specificity were statistically different between SEE and ITLPE for the detection of myometrial invasion (P = 0.031, 0.016). According to the comparison between FIPE and histopathologic findings, the irregular endomyometrial junction was found in 30/77 (38.9%) cases, 24/30 (80.0%) with myometrial infiltration and 6/30 (20.0%) cases without myometrial infiltration.

Conclusions

FIPE was the irregular endomyometrial junction. It can be found in patients with or without myometrial infiltration and may lead to the overestimation of myometrial invasion by SEE on DCE-MRI. ITLPE presented high diagnostic performance and specificity for myometrial invasion in patients with low-risk endometrial carcinoma.

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.

Endometrial Cancer, the Current International Federation of Gynecology and Obstetrics Staging System, and the Role of Imaging

Imaging plays a crucial role in the diagnosis, staging, and follow-up of endometrial cancer. Endometrial cancer is staged surgically using the International Federation of Gynecology and Obstetrics (FIGO) staging system. Preoperative imaging can complement surgical staging but is not yet considered a required component in the current FIGO staging system. Preoperative imaging can help identify some tumor characteristics and tumor spread, both locally and distally. More accurate assessment of endometrial cancers optimizes management and treatment plan, including degree of surgical intervention. In this article, we review the epidemiology, FIGO staging system, and the importance of imaging in the staging of endometrial cancer.

Magnetic Resonance Imaging in Local Staging of Endometrial Carcinoma: Diagnostic Performance, Pitfalls, and Literature Review

Aims and background

To assess the diagnostic accuracy of magnetic resonance imaging in local staging of endometrial carcinoma, and to review the results and pitfalls described in the literature.

Methods

Thirty women with a histological diagnosis of endometrial carcinoma underwent magnetic resonance imaging. Unenhanced T2-weighted and dynamic contrast-enhanced T1-weighted sequences were obtained. Hysterectomy and salpingo-oophorectomy was performed in all patients. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated for the detection of deep myometrial and cervical infiltration.

Results

For deep myometrial infiltration T2-weighted sequences reached a sensitivity of 85%, specificity of 76%, PPV of 73%, NVPof 87%, and accuracy of 80%, while contrast-enhanced scans reached a sensitivity of 90%, specificity of 80%, PPV of 82%, NPV of 89%, and accuracy of 85%. For cervical infiltration T2-weighted sequences reached a sensitivity of 75%, specificity of 88%, PPV of 50%, NPV of 96%, and accuracy of 87%, while contrast-enhanced scans reached a sensitivity of 100%, specificity of 94%, PPV of 75%, NPV of 100%, and accuracy of 95%.

Conclusions

Unenhanced and dynamic gadolinium-enhanced magnetic resonance allows accurate assessment of myometrial and cervical infiltration. Information provided by magnetic resonance imaging can define prognosis and management.

Evaluating Myometrial Invasion in Endometrial Cancer: Comparison of Reduced Field-of-view Diffusion-weighted Imaging and Dynamic Contrast-enhanced MR Imaging

PURPOSE

To compare the diagnostic ability of reduced FOV diffusion-weighted (DW) MR imaging with that of 3D dynamic contrast-enhanced (DCE) MR imaging in evaluating the depth of myometrial invasion in patients with endometrial cancer.

METHODS

Three tesla MR images including T₂-weighted imaging, reduced FOV DW imaging and 3D DCE MR imaging in sagittal and oblique axial (short axis) planes in 25 women with surgically proven endometrial cancer were retrospectively evaluated. The depth of myometrial invasion (stage S: < 50% vs stage D: ≥ 50%) on MR imaging was correlated with surgical pathology results.

RESULTS

The 25 endometrial cancers included 16 stage S and 9 stage D tumors. The depth of myometrial invasion could be accurately evaluated in 68% of the cases for T₂-weighted imaging, 92% for 3D DCE MR imaging, and 96% for reduced FOV DW imaging. In two patients with coexisting adenomyosis, both T₂-weighted imaging and 3D DCE MR imaging failed to reveal the deep myometrial invasion, and reduced FOV DW imaging clearly demonstrated the tumor margin in the cases. Combination of reduced FOV DW imaging reading together with T₂-weighted imaging improved the assessment of myometrial invasion with a diagnostic accuracy of up to 100%.

CONCLUSIONS

Addition of reduced FOV DW imaging may improve the staging accuracy of MR imaging for endometrial cancer in assessing the depth of myometrial invasion. Especially, reduced FOV DW imaging has an advantage in assessing the depth of myometrial invasion for patients with coexisting adenomyosis. Reduced FOV DW imaging can be an alternative to 3D DCE MR imaging in evaluating myometrial invasion of endometrial cancer without the use of contrast medium.

Role of SUVmax and GLUT-1 Expression in Determining Tumor Aggressiveness in Patients With Clinical Stage I Endometrioid Endometrial Cancer

OBJECTIVE

The aim of this study was to determine the role of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography in estimating tumor aggressiveness in patients with clinical stage I endometrial cancer and the correlation between aggressiveness and expression of glucose transporter 1 (GLUT-1).

METHODS

F-fluorodeoxyglucose positron emission tomography/computed tomography was performed on 43 patients with clinical stage I endometrioid endometrial cancer. (18)F-fluorodeoxyglucose uptake was quantified by calculating the maximum standardized uptake value (SUV(max)) and GLUT-1 expression status based on immunohistochemistry.

RESULTS

The mean (SD) SUV(max) of the primary tumor was 8.55 (5.04). The mean SUV(max) and GLUT-1 expression in stage IB and stage IC were significantly higher than that in stage IA (P = 0.001; P = 0.003). The mean (SD) SUV(max) was 6.81 (4.55) in grade 1, 10.92 (4.61) in grade 2, and 15.35 (1.34) in grade 3 (grade 1 vs grade 2 and 3; P = 0.005). The mean (SD) GLUT-1 expression was 1.17 (0.94) in grade 1, 2.00 (0.94) in grade 2, and 3.00 (0.00) in grade 3 (grade 1 vs grade 2 and 3; P = 0.017).

CONCLUSIONS

Tumor aggressiveness, such as myometrial invasion or tumor grade, had a positive correlation with the SUV(max) and GLUT-1 expression in patients with clinical stage I endometrioid endometrial cancer.

MR assessment of myometrial invasion in women with endometrial cancer: discrepancy between T2-weighted imaging and contrast-enhanced T1-weighted imaging

PURPOSE

The purpose of the study was to investigate how frequently discrepant imaging findings are encountered between T2-weighted imaging and contrast-enhanced T1-weighted imaging in the preoperative magnetic resonance (MR) assessment of myometrial invasion in women with endometrial cancer.

METHODS

Seventy-one consecutive women (mean age, 59 years; age range 35-86 years) with endometrial cancer who underwent preoperative MR imaging were included in this single-institution, retrospective study. Depth of myometrial invasion was separately assessed on T2-weighted imaging and contrast-enhanced T1-weighted imaging, and the assessment was considered discrepant, when the two imaging sequences did not match each other. The image analysis also included potential pitfalls responsible for discrepant imaging findings, including the absence of the junctional zone, disruption of the junctional zone, extension to the uterine cornu, presence of leiomyoma and presence of adenomyosis. The results were correlated with histopathologic findings.

RESULTS

Of the 71 women, 19 (26.8%) showed discrepant imaging findings between T2-weighted imaging and contrast-enhanced T1-weighted imaging. Histopathologic findings revealed that contrast-enhanced T1-weighted imaging correctly depicted endometrial cancers in all women with discrepant MR imaging findings. Among the analyzed potential pitfalls, only disruption of the junctional zone showed a significant difference between women with concordant MR imaging findings (29.5%, 13/44) and women with discordant MR imaging findings (93.8%, 15/16) (p = 0.000).

CONCLUSION

In the preoperative MR assessment of myometrial invasion in women with endometrial cancer, discrepant imaging findings between T2-weighted imaging and contrast-enhanced T1-weighted imaging are frequently encountered, especially when the junctional zone is disrupted.

MR staging accuracy for endometrial cancer based on the new FIGO stage

BACKGROUND

Magnetic resonance imaging (MRI) has been frequently used to determine a preoperative treatment plan for gynecologic cancers. However, the MR accuracy for staging an endometrial cancer is not satisfactory based on the old FIGO staging system.

PURPOSE

To evaluate MR accuracy for staging endometrial cancer using the new FIGO staging system.

MATERIAL AND METHODS

Between January 2005 and May 2009, 199 women underwent surgery due to endometrial cancer. In each patient, an endometrial cancer was staged using MR findings based on the old FIGO staging system and then repeated according to the new FIGO staging system for comparison. Histopathologic findings were used as a standard of reference.

RESULTS

The accuracy of MRI in the staging of endometrial carcinoma stage I, II, III, and IV using the old FIGO staging system were 80% (159/199), 89% (178/199), 90% (179/199), and 99% (198/199), respectively, compared to 87% (174/199), 97% (193/199), 90% (179/199), and 99% (198/199), respectively, when using the new FIGO staging criteria. The overall MR accuracy of the old and new staging systems were 51% (101/199) and 81% (161/199), respectively.

CONCLUSION

MRI has become a more useful tool in the preoperative staging of endometrial cancers using the new FIGO staging system compared to the old one with increased accuracy.

Diagnostic possibility of diffusion tensor imaging for the evaluation of myometrial invasion in endometrial cancer: an ex vivo study

PURPOSE

To investigate the feasibility of magnetic resonance imaging (MRI) diffusion tensor imaging (DTI) for evaluating the myometrial invasion of uterine endometrial cancer.

MATERIALS AND METHODS

Twelve specimens of uterine endometrial cancer were obtained. The depth of myometrial invasion was classified as stage E (limited to the endometrium; n = 4), stage S (superficial invasion of less than 50% of the myometrium; n = 5), or stage D (deep invasion of greater than 50% of the myometrium; n = 3). The specimens were fixed in 10% formalin and stored at 4°C before imaging. At 15 hours after fixation, MRI was performed using a 4.7-T experimental imager/spectrometer system.

RESULTS

We found a high fractional anisotropy (FA) value zone (anisotropic zone) at the myometrium adjacent to the tumor on FA maps of histopathological stage S and stage D cancers, whereas the anisotropic zone did not exist in stage E cancers. Histopathological analysis showed that compared to the other regions, the anisotropic zone had tightly packed stromal tissue. The disruption of the anisotropic zone was consistent with myometrial invasion.

CONCLUSION

Our ex vivo study suggests that DTI might be a useful tool for the diagnosis of myometrial invasion of uterine endometrial cancer ex vivo.

Imaging of endometrial and cervical cancer

In this article we review the ever increasing role of imaging in endometrial and cervical cancer. Magnetic resonance imaging (MRI) has emerged as the most widely used technique in the management of women with gynaecological cancer. In endometrial cancer, MRI is reliable in identifying myometrial and cervical invasion and extra-uterine disease, thereby informing preoperative surgical planning. In cervical cancer, MRI plays a crucial role in distinguishing early from advanced disease, thereby stratifying patients for surgery and chemoradiation. MRI is also valuable in assessing proximal extension of cervical tumours in young women with early stage disease for feasibility of fertility preserving surgery. In both cancers, imaging is used for diagnosing nodal metastases, detection of recurrence, and dealing with complications of both the disease and treatment.

Staging of endometrial cancer with MRI: guidelines of the European Society of Urogenital Imaging

The purpose of this study was to define guidelines for endometrial cancer staging with MRI. The technique included critical review and expert consensus of MRI protocols by the female imaging subcommittee of the European Society of Urogenital Radiology, from ten European institutions, and published literature between 1999 and 2008. The results indicated that high field MRI should include at least two T2-weighted sequences in sagittal, axial oblique or coronal oblique orientation (short and long axis of the uterine body) of the pelvic content. High-resolution post-contrast images acquired at 2 min +/- 30 s after intravenous contrast injection are suggested to be optimal for the diagnosis of myometrial invasion. If cervical invasion is suspected, additional slice orientation perpendicular to the axis of the endocervical channel is recommended. Due to the limited sensitivity of MRI to detect lymph node metastasis without lymph node-specific contrast agents, retroperitoneal lymph node screening with pre-contrast sequences up to the level of the kidneys is optional. The likelihood of lymph node invasion and the need for staging lymphadenectomy are also indicated by high-grade histology at endometrial tissue sampling and by deep myometrial or cervical invasion detected by MRI. In conclusion, expert consensus and literature review lead to an optimized MRI protocol to stage endometrial cancer.

MR imaging in endometrial carcinoma as a diagnostic tool for the prediction of myometrial invasion and lymph node metastasis

PURPOSE

The purpose of this study was to evaluate the factors that are associated with the accuracy of magnetic resonance (MR) imaging for predicting myometrial invasion and lymph node metastasis in women with endometrial carcinoma.

MATERIALS AND METHODS

We retrospectively reviewed the medical records and preoperative MR imaging reports of 128 women who had pathologically proven endometrial carcinoma. We compared the MR imaging and the histopathology findings.

RESULTS

The sensitivity, specificity and accuracy for identifing any myometrial invasion (superficial or deep) were 0.81, 0.61 and 0.74, respectively; these values for deep myometrial invasion were 0.60, 0.94 and 0.86, respectively. The sensitivity, specificity and accuracy of MR imaging for detecting lymph node metastasis were 50.0%, 96.6% and 93.0%, respectively. The patients who were older, had more deliveries and a larger tumor size more frequently had incorrect prediction of deep myometrial invasion (p=0.034, p=0.044, p=0.061, respectively). A higher tumor grade, a histology other than the endometrioid type, myometrial invasion on MR findings and a larger tumor size were associated with a more frequent false-negative prediction of lymph node metastasis (p=0.018, p=0.017, p=0.002, p=0.047, respectively). A larger tumor size was also associated with more frequent false-positive results (p=0.009).

CONCLUSIONS

There are several factors that make accurate assessment of myometrial invasion or lymph node metastasis difficult with using MRI; therefore, the patients with these factors should have their MR findings cautiously interpreted.

MRI of malignant neoplasms of the uterine corpus and cervix

OBJECTIVE

In this article, we review the role of MRI in the imaging of malignant neoplasms of the uterine corpus and cervix, describing its role in staging, treatment planning, and follow-up.

CONCLUSION

MRI is not officially incorporated in the International Federation of Gynecology and Obstetrics (FIGO) staging system, but is already widely accepted as the most reliable imaging technique for the diagnosis, staging, treatment planning, and follow-up of both endometrial and cervical cancer. MRI protocols need to be optimized to obtain the best results and avoid pitfalls.

Accuracy of MR imaging for the prediction of myometrial invasion of endometrial carcinoma

OBJECTIVES

To retrospectively evaluate the accuracy of magnetic resonance (MR) imaging for the prediction of depth of myometrial invasion in the preoperative assessment of women with endometrial carcinoma.

METHODS

We retrospectively reviewed the medical records and MR imaging reports of 120 women with pathologically-proven endometrial carcinoma who underwent preoperative pelvic MR imaging between June 1997 and February 2006. Tumor signal intensity, the appearance of the junctional zone (JZ), the presence of large polypoid tumors and leiomyomas were analyzed. Univariate logistic-regression analysis was performed to identify associations between incorrect MR staging and the study variables.

RESULTS

Data from 120 patients were registered for the current study and analyzed. The sensitivity, specificity and accuracy of the MR imaging in assessment of myometrial invasion among patients with endometrial carcinoma were: 50.6%, 89.2% and 62.5% respectively. MR differentiation of deep myometrial invasion from superficial disease had an 83.3% accuracy (100 of 120 cases). Isointense JZ to myometrium (P<0.001), and the presence of polypoid tumors (P=0.037) on MR imaging were significantly associated with an underestimation of myometrial invasion by endometrial carcinoma.

CONCLUSIONS

Isointense JZ to myometrium and polypoid tumors are difficult to accurately evaluate for myometrial invasion of endometrial carcinoma by MR imaging.

MR staging of endometrial carcinoma

Endometrial cancer is the second most common gynaecological malignancy. The usual presentation with post-menopausal bleeding results in an early diagnosis in most cases and thus there is opportunity for cure. Magnetic resonance (MR) imaging is pivotal in the decision-making process regarding treatment options. We present a review of the magnetic resonance (MR) findings to illustrate its role in the staging of endometrial cancer.

Pitfalls in staging uterine neoplasm with imaging: a review

This review analyzes current pitfalls in pretreatment staging of endometrial and cervical carcinoma with magnetic resonance imaging (MRI) based on a critical review of the literature. Technical, patient, and tumor-related characteristics were analyzed to improve further staging of uterine neoplasm with MRI. For endometrial carcinoma staging, contrast-enhanced dynamic imaging appears essential to avoid false-positive findings for deep myometrial invasion by better delineating tumor from normal myometrium. However, leiomyomas, adenomyosis, and grade 3 tumors provide difficulties in staging for pathologists and radiologists. Slice orientation perpendicular to the long axis of the cervical channel might improve false-negative findings for deep stromal invasion on T2-weighted images in endometrial and cervical cancer. Contrast-enhanced sequences do not improve diagnosis of parametrial or vaginal invasion in cervical cancer. Assessment of lymph node invasion by any imaging modality has limited sensitivity in detecting lymph node metastasis smaller than 5 mm. Knowledge of diagnostic criteria is critical to avoid false-negative findings for bladder wall invasion. Higher spatial resolution with dedicated multichannel pelvic phase array coils, smaller fields of view and section thickness, and careful comparison of T2-weighted and contrast-enhanced sequences are strategies that might avoid misinterpretation of pelvic MRI in staging uterine neoplasm.

MR imaging in endometrial carcinoma as a diagnostic tool for the absence of myometrial invasion

OBJECTIVE

To evaluate whether magnetic resonance imaging (MRI) is a reliable modality for verifying preoperative diagnosis of stage IA endometrial carcinoma.

METHODS

One hundred sixteen patients with endometrial carcinoma underwent preoperative pelvic non-contrast T2-weighted or dynamic MRI. We compared the interpretations of the MRI results with the histological findings of the resected uterus.

RESULTS

In assessing the depth of myometrial invasion, the accuracy of MRI was 62.1%. As to the presence of cancerous myometrial invasion, the positive predictive value was 94.4% as high as previously reported by other institutions. However, the negative predictive value, the probability of the absence of myometrial invasion, was only 42.2%. Even when dynamic study was applied to the patient, the value only improved up to 60.0%.

CONCLUSION

MRI has a definite advantage in evaluating deep myometrial invasion, but not the absence of invasion. We should take precautions against the risk of under-diagnosis when selecting stage IA endometrial carcinoma with use of MRI to preserve fertility or to eliminate lymphadenectomy.

Imaging of endometrial adenocarcinoma

Endometrial cancer is the most common gynaecological malignancy and the incidence rising. Prognosis depends on age of patient, histological grade, depth of myometrial invasion and cervical invasion and lymph node metastases. Myometrial invasion and accurate cervical involvement cannot be predicted clinically. Pre-treatment knowledge of these criteria is advantageous in order to plan treatment. The clinical challenge is to effectively select patients at risk of relapse for more radical treatment whilst avoiding over treating low risk cases. This is important as endometrial cancer predominately occurs in postmenopausal women with co-morbidities. Modern imaging provides important tools in the accurate pre-treatment assessment of endometrial cancer and may optimize treatment planning. However, there is little consensus to date on imaging in the routine preoperative assessment of endometrial carcinoma and practice varies amongst many gynaecologists. Transvaginal ultrasound is often the initial imaging examination for women with uterine bleeding. However, once the diagnosis of endometrial cancer has been made, contrast-enhanced magnetic resonance imaging (MRI) provides the best assessment of the disease. The results of contrast-enhanced MRI may identify patients who need more aggressive therapy and referral to a cancer centre. In this article we review the role of imaging in the diagnosis and staging/preoperative assessment of endometrial carcinoma.

FDG PET for the assessment of myometrial infiltration in clinical stage I uterine corpus cancer

OBJECTIVE

For surgical planning of uterine corpus cancer, prior knowledge of the depth of myometrial invasion is important. Curative tumour resection is possible in superficial invasion (stages IA and IB), while post-surgical chemotherapy or radiation therapy is required in deep invasion (stage IC). We evaluated the value of positron emission tomography with 2-[(18)F]fluoro-2-deoxy-D-glucose (FDG PET) for estimating the myometrial invasion in uterine corpus cancer.

METHODS

We studied 22 patients with clinical stage I uterine corpus cancer, who underwent FDG PET prior to surgery. Standardized uptake value (SUV; tracer activity per injected dose normalized to body weight) was calculated on the PET image. PET findings were compared with magnetic resonance imaging (MRI) and the surgical staging.

RESULTS

The surgical stage was IA in five, IB in 11 and IC in six patients. SUVs in deep invasion (15.69+/-4.73, 8.83-21.84) were significantly higher than those in superficial invasion (9.09+/-3.29, 2.68-15.41) (P<0.005). Using 12.0 as a cut-off value of SUV for the differentiation of these two groups, PET results were correct in 19 patients but were incorrect in three patients. Although both PET and MRI provided correct staging in 14 patients, only MRI overestimated the myometrial invasion in four patients with stage IB and showed inconclusive findings in one patient with stage IC. Four of these five patients were post-menopausal.

CONCLUSIONS

The cut-off value of SUV (=12.0) may be a useful index for the differentiation of superficial invasion and deep invasion. FDG PET may be feasible for predicting the myometrial infiltration of uterine corpus cancer, especially when uterine atrophy makes it difficult at MRI in post-menopausal patients.

Percutaneous uterine artery embolization for the treatment of symptomatic fibroids: current status

Uterine artery embolization (UAE) is increasingly being used as an alternative treatment to hysterectomy for symptomatic fibroids. Symptoms of pelvic pressure, urinary frequency and menorrhagia are controlled in 73-98% of patients who undergo UAE. At the 1-year follow-up, the uterus may shrink by up to 55% but re-growth of fibroid may however occur. The rate of major complications and amenorrhoea following this procedure is low, ranging in most series from 1 to 3.5% and 1 to 7%, respectively. Nevertheless, the rate of amenorrhoea in women over 45 seems to be higher. In order to completely block the arterial supply to the fibroid, UAE is typically performed in both uterine arteries. Different embolic agents are used such as polyvinyl alcohol, gelfoam and more recently gelatine tris-acryl microspheres. After UAE, perfusion of the uterus is maintained. Uterine function is therefore conserved and although women who become pregnant after UAE seem to be at risk for malpresentation, pre-term birth, cesarean delivery and postpartum hemorrhage, successful pregnancies after UAE have been reported in some series. A major technical problem with UAE remains the possible presence of fibroid blood supply from other sources, such as the ovarian arteries or other pelvic branches, which can lead to failure of the procedure. In conclusion, although randomized trials are still underway, UAE appears a good option for those patients who whish to conserve their fertility or when surgery is contra-indicated. However, to evaluate the long-term effects of UAE longer follow up is required.

Myometrial invasion and cervical invasion by endometrial carcinoma: Evaluation by CO2-volumetric interpolated breathhold examination (VIBE)

PURPOSE

To assess myometrial invasion and cervical invasion by endometrial carcinoma, using CO2-volumetric interpolated breathhold examination (VIBE) enabling more precise evaluation of depth of tumor invasion.

MATERIALS AND METHODS

CO2-VIBE was performed in 21 cases of endometrial carcinoma (Stage Ia-IIb) prior to treatment. The images were interpreted by performing multiplanar reconstruction (MPR), and the findings obtained from the images (degree of myometrial invasion and presence or absence of cervical invasion) were assessed in comparison with the histopathological diagnosis.

RESULTS

The sites of the endometrial carcinoma lesions were clearly visualized by the CO2-VIBE method. Evaluation of the degree of myometrial invasion enabled a high correct diagnosis rate of 90.5%, and evaluation for the presence of cervical invasion also allowed a high correct diagnosis rate of 90.5%.

CONCLUSION

VIBE permits evaluation of any plane desired by means of thin slices, and it is a truly revolutionary method for preoperative evaluation of depth of invasion of endometrial carcinoma that enables highly accurate determination of the extent of lesion sites and degree of invasion before treatment.

The role of MRI in the conservative management of endometrial cancer

BACKGROUND

Young patients with endometrial cancer who desire to preserve their fertility often decline hysterectomy in favor of conservative progestin therapy. Proper candidates should have disease confined to the uterus and a well-differentiated tumor. One of the evolving techniques to evaluate the extent of the disease and myometrial or cervical invasion is magnetic resonance imaging (MRI).

CASE

A young patient with early-stage endometrial cancer initially declined surgery and was treated with megestrol. MRI suggested myoinvasion, and the patient consented to surgical staging. The final pathology revealed no residual carcinoma.

CONCLUSIONS

The accuracy of MRI in detecting myoinvasion is limited, and as such results should be interpreted with caution when this information is used in counseling a young patient regarding surgical staging for endometrial cancer.

Endometrial Carcinoma in Adenomyosis:Assessment of Myometrial Invasion on T2-Weighted Spin-Echo and Gadolinium-Enhanced T1-Weighted Images

OBJECTIVE

The aim of our study was to compare T2-weighted and contrast-enhanced dynamic T1-weighted images with histologic findings in assessing the depth of myometrial invasion by endometrial carcinoma in adenomyosis.

MATERIALS AND METHODS

We retrospectively reviewed the MRIs of 11 patients who had a total of 12 lesions of endometrial carcinoma within adenomyosis. T2-weighted and contrast-enhanced dynamic T1-weighted images were compared with the histologic findings separately. We assessed the extent of myometrial invasion by endometrial carcinomas. The depth of myometrial invasion seen on MRI was classified as stage S (superficial invasion), stage D (deep invasion), or undetectable. The staging accuracies of each sequence were assessed. The tumor-myometrium contrast-to-noise ratios were calculated for each sequence.

RESULTS

The histologic specimens revealed that myometrial invasion was deep in seven of 12 lesions and superficial in five. On T2-weighted images the depth of invasion was underestimated in two lesions and impossible to determine in five lesions. On dynamic T1-weighted images the depth of invasion was overestimated in one lesion and underestimated in one lesion. The staging accuracy on dynamic T1-weighted images (83%) was significantly higher than that on T2-weighted images (42%). The contrast-to-noise ratio was significantly higher on dynamic T1-weighted studies during the early phase (mean +/- SD, 2.68 +/- 0.94) than it was on T2-weighted studies (1.74 +/- 1.05) and during the delayed phase (2.01 +/- 0.86).

CONCLUSION

When adenomyosis coexists with endometrial cancer at the same site on T2-weighted images, contrast-enhanced dynamic T1-weighted imaging improves the accuracy of staging.

Clinical over- and under-estimation in patients who underwent hysterectomy for atypical endometrial hyperplasia diagnosed by endometrial biopsy: the predictive value of clinical parameters and diagnostic imaging

OBJECTIVE

The aim of this study was to analyze the clinical and imaging characteristics in patients diagnosed with atypical endometrial hyperplasia based on endometrial biopsy in comparison with the final diagnosis from resected uteri; i.e. to determine the rates of underestimation (endometrial cancer), equivalent diagnosis (atypical hyperplasia), and overestimation (hyperplasia without atypia or non-hyperplastic lesion).

MATERIALS AND METHODS

We reviewed 33 patients who were diagnosed with atypical endometrial hyperplasia by endometrial biopsy using a small curette and then underwent total abdominal hysterectomy between September 1992 and May 2002. Clinical parameters obtained from patients' charts, and imaging analyses using transvaginal ultrasonography (TUS) and magnetic resonance (MR) imaging were retrospectively re-examined.

RESULTS

Among 33 patients who underwent hysterectomy due to a diagnosis of atypical hyperplasia, nine cases (27.2%) were underestimated (cancer), nine cases (27.2%) were equivalent and 15 cases (45.6%) were overestimated as indicated by examination of the endometrium of the resected uterus. There was no difference among these groups in either clinical parameters or diagnostic images obtained by TUS or MR.

CONCLUSION

Diagnosis of atypical endometrial hyperplasia by endometrial biopsy often resulted in under- or over-estimation, as shown by examination after hysterectomy. As there is neither a reliable clinical parameter nor imaging feature to distinguish between these groups, hysterectomy is still the best treatment for these patients if they are willing to give up their fertility.

Combined use of magnetic resonance imaging, CA 125 assay, histologic type, and histologic grade in the prediction of lymph node metastasis in endometrial carcinoma

OBJECTIVE

The aim of this study was to predict retroperitoneal lymph node metastasis during the preoperative examination of patients with endometrial carcinoma and to determine whether lymphadenectomy must be performed.

STUDY DESIGN

This study was carried out on 214 patients with endometrial carcinoma. Preoperative evaluators were volume index, depth of myometrial invasion (as assessed by magnetic resonance imaging), serum CA 125 level, histologic type, and histologic grade. With the use of receiver operating characteristic curves, cutoff values of volume index and serum CA 125 levels were determined. The relationships of these evaluators with pelvic lymph node metastasis were investigated by multivariate analysis with a logistic regression model. The relationships of these evaluators with para-aortic lymph node metastasis were investigated in the same way.

RESULTS

Histologic type, volume index, histologic grade, and serum CA 125 level were found to be independent risk factors for pelvic lymph node metastasis; serum CA 125 level and volume index were found to be independent risk factors for para-aortic lymph node metastasis. Among 110 cases with no risk factors for pelvic lymph node metastasis, pelvic lymph node metastasis was observed in 4 cases (3.6%). On the other hand, only 1 case of 128 cases (0.7%) with no risk factors for para-aortic lymph node metastasis actually had metastasis.

CONCLUSION

Careful consideration of the possibility of the elimination of the requirement of retroperitoneal lymphadenectomy is needed in cases with no risk factors for lymph node metastasis. However, our results suggest that para-aortic lymphadenectomy may not be necessary in cases with no risk factors for para-aortic lymph node metastasis.

Uterine artery embolisation for symptomatic fibroids: clinical results in 400 women with imaging follow up

OBJECTIVE

To evaluate the mid-term efficacy and complications of uterine artery embolisation in women with symptomatic fibroids. To assess reduction in uterine and dominant fibroid volumes using ultrasound and magnetic resonance imaging.

DESIGN

Prospective observational single-centre study.

SETTING

A district general hospital in Surrey and a private hospital in London.

METHODS

Four hundred consecutive women were treated between December 1996 and February 2001. Indications for treatment were menorrhagia, menstrual pain, abdominal swelling or bloating and other pressure effects. Uterine artery embolisation was performed using polyvinyl alcohol particles and platinum coils.

MAIN OUTCOME MEASURES

Imaging was performed before embolisation and at regular intervals thereafter. Clinical evaluation was made at regular intervals after embolisation to assess patient outcome.

RESULTS

Bilateral uterine artery embolisation was achieved in 395 women, while 5 women had a unilateral procedure. With a mean clinical follow up of 16.7 months, menstrual bleeding was improved in 84% of women and menstrual pain was improved in 79%. Using ultrasound, the median uterine and dominant fibroid volumes before embolisation were 608 and 112 cc, respectively, and after embolisation 255 and 19 cc, respectively (P = .0001). Three (1%) infective complications requiring emergency hysterectomy occurred. Twenty-three (6%) patients had clinical failure or recurrence. Of these, nine (2%) had a hysterectomy. Twenty-six (7%) women had permanent amenorrhoea after embolisation including four patients under the age of 45 (2%). Of these, amenorrhea started between 4 and 18 months after embolisation, and only three had elevated follicle stimulating hormone levels when amenorrhea developed. Thirteen (4%) women had chronic vaginal discharge considered as a major irritant. Thirteen pregnancies occurred in 12 patients. Ninety-seven percent of women were pleased with the outcome and would recommend this treatment to others.

CONCLUSIONS

Uterine artery embolisation is associated with a high clinical success rate and good fibroid volume reduction. Infective complications requiring hysterectomy, amenorrhoea under the age of 45 and chronic vaginal discharge may complicate the procedure.

Evaluation of endometrial cancer with 3D-VIBE (volume interpolated breath-hold examination) using intrauterine CO2 gas

To evaluate the myometrial infiltration of the endometrial cancer prior to aggressive treatment, dynamic MRI (magnetic resonance imaging) has attracted attention. However, it has also been found that in a number of cases, MRI exhibits inconsistent results with regards to the extent of the infiltration into this component of the uterine body. To overcome this limitation, the authors designed a method to delineate the tumor morphology more clearly by injecting CO2 gas into the uterine cavity. This procedure was combined with VIBE (volumetric interpolated breath-hold examination) to determine more precisely the depth of the tumor invasion. From our clinical results, the efficacy of the method was evaluated. On four patients with endometrial cancers (stage Ia-Ic), CO2 was injected to dilate the intra-uterine space through a catheter equipped with a balloon that had been introduced into the uterine cavity, after which VIBE was conducted. The images were interpreted by MPR (multiplanar reconstruction) and the findings from these images were compared against the histopathological findings. By employing this method, it was possible to delineate clearly the tumorous lesion in the uterine body, and three-dimensional images of the tumor invasion was acquired. The site and extent of tumor invasion in the myometrium were generally consistent with the histopathological findings. This method allows one to observe multiple planes by using thin slices. By dilating the uterine cavity, the site of involvement and the extent of invasion can be more precisely defined before treatment. It is truly a revolutionary procedure for determining-prior to surgery-the depth of invasion of a cancer located in the uterine body.

Fibroid embolization

The most common surgical treatment for fibroids is hysterectomy and approximately 30,000 are carried out annually in the UK for this condition. The operation, however, carries a significant complication rate. Since the first case was carried out in 1989 there has been increasing interest in the interventional radiological procedure called fibroid embolization where angiographic techniques are used to occlude the vascular supply of fibroids. This article is a review of the world experience of fibroid embolization, its development, techniques, indications, results and complications. So far evidence indicates very promising mid-term results but more long-term comprehensive data is needed from large trials.

Imaging of cancer of the endometrium

Transvaginal US is often the initial imaging examination for women with dysfunctional (postmenopausal or intermenstrual) uterine bleeding. However, once the diagnosis of endometrial cancer has been made, contrast-enhanced MRI should be performed in patients who require multifactorial assessment (eg, depth of myometrial invasion, cervical involvement, lymph node metastasis). The results of contrast-enhanced MRI help distinguish patients who need more aggressive therapy and referral to a gynecologic oncologist from those who will do well treated by a community gynecologist.

Staging of gynecologic malignancies

Magnetic resonance imaging (MRI) is gaining momentum for staging gynecologic malignancies. MRI staging is an adjunct to clinical and surgical staging in women with cervical or endometrial cancer, respectively. For women with possible adnexal pathology, MRI is useful for lesion characterization. In patients with ovarian cancer, MRI determination of disease extent helps treatment planning, either as a surgical roadmap or to identify nonresectable patients.

Endometrial carcinoma: assessment of myometrial invasion with plain and gadolinium-enhanced MR imaging

The purpose of this study was to determine the accuracy of magnetic resonance imaging (MRI) for evaluating the depth of myometrial invasion, potential sources of pitfalls, and the usefulness of contrast-enhanced series. Eighty-five patients with a pathologic diagnosis of endometrial carcinoma underwent preoperative MRI (plain and contrast-enhanced). Grade of myometrial invasion, presence of junctional zone (JZ), fibromyomas, and tumoral thickness were evaluated by two groups of radiologists blinded to pathologic results. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of MRI in determining the depth of myometrial invasion were evaluated. The sensitivity/specificity for plain MR was 64.1-64.1/93.5-100 for both observers. Assessing deep myometrial invasion, sensitivity, and NPV improved significantly (P = 0.002, P = 0.003 for both observers) when comparing plain and whole study series. Tumoral thickness (P = 0.16, P = 0.13, for the two observers) and presence or absence of JZ (P = 0.41, P = 0.14) did not influence myometrial invasion assessment. Gadolinium-enhanced series improve the assessment of deep myometrial invasion in endometrial carcinoma. J. Magn. Reson. Imaging 2000;12:460-466.

Abnormal uterine cavity: differential diagnosis with MR imaging

The objective of the study was to assess the usefulness of magnetic resonance (MR) imaging in distinguishing malignant from benign conditions in patients with an abnormal uterine cavity. Fifty-four patients that were suspected of having abnormal uterine cavities were retrospectively evaluated by using MR imaging. The diagnosis of an abnormal uterine cavity included a thickened endometrium, and/or a endometrial mass, and/or a submucosal mass. Threshold values to classify the uterine cavity as abnormal on sagittal T2-weighted images were >10 mm for premenopausal women and >5 mm for postmenopausal women. Malignancy was diagnosed when lesions invaded the myometrial/junctional zone, and/or lesion enhancement was lower than that of the adjacent myometrium. The results found that histology confirmed 18 malignant and 37 benign lesions. Twelve of 15 endometrial carcinomas and 3 malignant mixed mesodermal tumors (MMMT) were correctly characterized as malignant on enhanced T1-weighted images; whereas 6 of 15 endometrial carcinomas and 3 MMMT were correctly characterized on T2-weighted images. Thirty-four of 37 benign cases were correctly characterized as not malignant on enhanced T1-weighted images. One of 14 submucosal leiomyomas, one endometrial stromal metaplasia, and one of ten pathologically normal endometria were misdiagnosed on enhanced T1-weighted images but were correctly diagnosed on T2-weighted images. The overall sensitivity, specificity, and accuracy for distinguishing malignant from benign central uterine masses were 83%, 92%, and 89% for enhanced T1-weighted image, and 50%, 97%, and 82% for T2-weighted image, respectively. We came to the conclusion that in diagnosing patients with abnormal uterine cavity, MR imaging may help differentiate malignant from benign disorders.