The Value of Shear Wave Elastography in Predicting the Risk of Endometrial Cancer and Atypical Endometrial Hyperplasia

Advancements in the application of uterine ultrasound elastography

PURPOSE OF REVIEW

This article reviews recent advances in ultrasound elastography in diagnosing and evaluating the normal nongravid uterus and the infertile uterus in the gynecologic patient.

RECENT FINDINGS

Focusing on the most recent primary literature, studies have demonstrated new findings among a breadth of gynecologic clinical settings. Studies in the nongravid uterus have found that menopausal status, age, and menstrual phase have not been associated with changes in uterine tissue stiffness. Focusing on myometrial disease, there have been conflicting data regarding the ability to distinguish uterine fibroids from adenomyosis. One area of expanding research surrounding uterine elastography includes the infertile population, where ongoing studies attempt to provide a predictive model using shear wave elastography (SWE) in patients undergoing in-vitro fertilization.

SUMMARY

Ultrasound elastography has become an increasingly studied and utilized tool in assessing physiologic and pathologic processes in the field of gynecology. Evaluating tissue stiffness through strain and SWE can serve to improve diagnosis of various uterine and cervical lesions, as well as prognosticate outcomes after fertility treatments. This growing area of research will continue to establish the role and application of ultrasound elastography into clinical practice.

Chinese guidelines on the management of endometrial hyperplasia

• Endometrial hyperplasia can be classified as either hyperplasia without atypia or atypical hyperplasia. • Abnormal uterine bleeding is the most common symptom of endometrial hyperplasia. Transvaginal ultrasound is recommended for initial imaging to evaluate endometrial hyperplasia (evidence level 2+), while transrectal ultrasound is recommended for virgo patients (evidence level 3). • Endometrial biopsy should be used to confirm diagnosis in patients where endometrial lesions are suspected. Effective histological approaches to make definite diagnoses include diagnostic curettage (evidence level 2++), hysteroscopic-guided biopsy (evidence level 2+) and endometrial aspiration biopsy (evidence level 2-). • Progesterone is the preferred medication for the treatment of endometrial hyperplasia without atypia. Compared to oral progestins, placement of a levonorgestrel-releasing intrauterine system (LNG-IUS) has been associated with higher regression rates, lower recurrence rates and fewer adverse events which can be the initial treatment method. (Meta evidence level 1-, RCT evidence level 2+). Ultrasound and endometrial biopsies should be performed every 6 months during treatment to evaluate its effect and treatment should continue until no pathological changes are observed in two consecutive endometrial biopsies. Hysterectomy is not the preferred choice of treatment for patients with endometrial hyperplasia without atypia. • Minimally invasive hysterectomy is indicated for patients with endometrial atypical hyperplasia (evidence level 1+), bilateral fallopian tubes should also be removed (evidence level 2+). In cases where surgery cannot be tolerated, fertility is desired or the patient is younger than 45 years old, medical therapy is recommended (evidence level 3). LNG-IUS is the preferred medical therapy method (evidence level 2+). Endometrial pathologic evaluation should be performed every 3 months during conservative treatments, with adjustments made to dosages or approaches based on observed response to medication. Treatment should continue until no pathological changes are detected in two consecutive endometrial biopsies (evidence level 2++). There is no indication of sentinel lymph nodes biopsy and/or lymphadenectomy for hyperplasia with or without atypia. • Total hysterectomy is recommended to treat patients with recurrent endometrial atypical hyperplasia (evidence level 3); however, medical conservative therapy may be considered for patients hoping to become pregnant in the future. • Patients with fully regressed disease who would like to become pregnant should be advised to seek assistance through assisted reproductive technologies (evidence level 3). • Long-term follow-up is suggested for patients after endometrial hyperplasia treatment (evidence level 2+). Patient education is imperative for improving medication adherence, increasing regression rates and lowering recurrence rates (evidence level 3).

Shear wave elastography to assess stiffness of the human ovary and other reproductive tissues across the reproductive lifespan in health and disease†

The ovary is one of the first organs to show overt signs of aging in the human body, and ovarian aging is associated with a loss of gamete quality and quantity. The age-dependent decline in ovarian function contributes to infertility and an altered endocrine milieu, which has ramifications for overall health. The aging ovarian microenvironment becomes fibro-inflammatory and stiff with age, and this has implications for ovarian physiology and pathology, including follicle growth, gamete quality, ovulation dynamics, and ovarian cancer. Thus, developing a non-invasive tool to measure and monitor the stiffness of the human ovary would represent a major advance for female reproductive health and longevity. Shear wave elastography is a quantitative ultrasound imaging method for evaluation of soft tissue stiffness. Shear wave elastography has been used clinically in assessment of liver fibrosis and characterization of tendinopathies and various neoplasms in thyroid, breast, prostate, and lymph nodes as a non-invasive diagnostic and prognostic tool. In this study, we review the underlying principles of shear wave elastography and its current clinical uses outside the reproductive tract as well as its successful application of shear wave elastography to reproductive tissues, including the uterus and cervix. We also describe an emerging use of this technology in evaluation of human ovarian stiffness via transvaginal ultrasound. Establishing ovarian stiffness as a clinical biomarker of ovarian aging may have implications for predicting the ovarian reserve and outcomes of Assisted Reproductive Technologies as well as for the assessment of the efficacy of emerging therapeutics to extend reproductive longevity. This parameter may also have broad relevance in other conditions where ovarian stiffness and fibrosis may be implicated, such as polycystic ovarian syndrome, late off target effects of chemotherapy and radiation, premature ovarian insufficiency, conditions of differences of sexual development, and ovarian cancer. Summary sentence:  Shear Wave Elastography is a non-invasive technique to study human tissue stiffness, and here we review its clinical applications and implications for reproductive health and disease.

The use of real time strain endometrial elastosonography plus endometrial thickness and vascularization flow index to predict endometrial receptivity in IVF treatments: a pilot study

BACKGROUND

The usefulness of endometrium strain elastosonography (SE) for the evaluation of endometrial receptivity in women undergoing in vitro fertilization (IVF) remains controversial. The objective of this prospective, observational study was to evaluate the correlation between endometrial thickness (EMT) and its related strain (ESR) on the day of ovulation triggering (hCG-d) and in vitro fertilization outcomes. Additionally, 3D Power Doppler vascular indices (3DPDVI) were also analysed.

METHODS

We included all the patients undergoing fresh IVF-single blastocyst transfer cycle from January 2021 to August 2021 at our center. On hCG-d, after B-mode scanning was completed to measure the EMT, the mode was changed to elastosonography to evaluate the ESR (ratio between endometrial tissue and the myometrium below). At the end of examination, the Endometrial Volume (EV) and 3DPDVI (vascularization index [VI], flow index [FI] and vascularization flow index [VFI]), were assessed. Statistical analysis was completed using STATA MP16 software.

RESULTS

A total number of 57 women were included. Based on the EMT on hCG-d, women were divided into two groups, Group 1: <7 mm and Group 2 ≥ 7 mm. Women with EMT < 7 mm had a significantly higher ESR (p = 0.004) and lower pregnancy rate (p = 0.04). Additionally, low ESR values were correlated with high VFI values (rho = -0.8; 95% CI = -0.9- -0.6; p < 0.0001) and EMT ≥ 7 mm could be predicted by low ESR (OR = 0.01; 95% CI = 0.01-0.30; p = 0.008, area under the ROC curve: 0.70). After all, in multiple logistic regression analysis, low values of ESR (p = 0.050) and high values of EMT (p = 0.051) on hCG-d had borderline statistical effects on pregnancy rate.

CONCLUSIONS

The ESR may be useful to improve the ultrasound evaluation of the endometrial quality in infertile women candidates to IVF/ICS. Given the small sample size of our study, the usefulness of strain elastosonography in this patients, needs further investigation.

Advances in the clinical application of ultrasound elastography in uterine imaging

Changes in tissue stiffness by physiological or pathological factors in tissue structure are identified earlier than their clinical features. Pathological processes such as uterine fibrosis, adenomyosis, endometrial lesions, infertility, and premature birth can manifest as tissue elasticity changes. In clinical settings, elastography techniques based on ultrasonography, optical coherence tomography, and magnetic resonance imaging are widely used for noninvasive measurement of mechanical properties in patients, providing valuable tool and information for diagnosis and treatment. Ultrasound elastography (USE) plays a critical role in obstetrics and gynecology clinical work because of its simplicity, non-invasiveness, and repeatability. This article reviews the recent progress of USE in uterine tumor diagnosis (especially early diagnosis and treatment effect evaluation), prediction of preterm birth, and intrauterine insemination. We believe that USE, especially shear wave elastography, may serve as a potential means to assess tissue stiffness, thereby improving the diagnosis and treatment of adenomyosis, fibroids, endometrial lesions, cervical cancer, and precise management of preterm birth and intrauterine insemination monitoring.