Uterine artery embolization for symptomatic fibroids with high signal intensity on T2-weighted MR imaging

Benign Uterine Disease: The Added Role of Imaging

Benign uterine diseases are very common gynecologic conditions that affect women mostly in reproductive age. Ultrasound examination is the first-line imaging technique, but MRI is more accurate for diagnosis, characterization, and patient management. In this review, we especially highlight the added value of MRI in the diagnosis of benign uterine disease, discuss their imaging characteristics, and describe the therapeutic options and the added value of MRI in the treatment planning.

Can pre-procedural MRI signal intensity ratio predict the success of uterine artery embolization in treatment of myomas?

Background/aim

Magnetic resonance (MR) images, signal intensity ratios calculated using region of interests (ROI) in T2W images by proportioning the dominant myoma to iliac muscle can aid patient selection and, thus, in achieving better outcomes with the uterine artery embolization (UAE) procedure. The present study investigates the association between the success of UAE treatment with signal intensity (SI) ratio of the dominant myoma to the iliac muscle in MR imaging performed prior to the procedure.

Materials and methods

This is a retrospective study and included 30 patients who admitted to our clinic between February 2017 and July 2019 due to symptoms associated with myoma and who underwent MR imaging before and after UAE treatment. All patients, MR images obtained before UAE treatment and at the 12th month after the procedure were evaluated. In MRI, SI values were calculated by proportioning the dominant myoma to the iliac muscle using circular ROI in T1 weighted (W), T2W, and post-contrast T1W images. In the present study, 50% or more volumetric regression of the myoma with infarction of fibroids (loss of enhancement) at the 12-month follow-up MRI after the procedure was considered a successful procedure.

Results

Myoma volumes calculated in MR images showed significant differences between the MRI performed before UAE procedure and the MRI performed at the 12th month after the procedure (p < 0.0001). SI ratio calculated from pre-procedure T2W MR images was found to be a significant determinant of 50% or more volumetric regression in the myoma after UAE procedure (p = 0.017), T1W, post-contrast T1W images were not statistically significant (p = 0.211).

Conclusion

Our results indicate that SI ratio of the dominant myoma to the iliac muscle calculated using ROI in T2W images of MR studies performed before UAE procedure can predict the success of the procedure.

Uterine Artery Embolization for Leiomyomas and Adenomyosis: A Pictorial Essay Based on Our Experience from 1300 Cases

Since its introduction in 1995, uterine artery embolization (UAE) has become an established option for the treatment of leiomyomas. Identification of a leiomyoma using arteriography improves the ability to perform effective UAE. UAE is not contraindicated in a pedunculated subserosal leiomyoma. UAE in a cervical leiomyoma remains a challenging procedure. A leiomyoma with high signal intensity on T2-weighted imaging responds well to UAE, but a malignancy with similar radiological features should not be misdiagnosed as a leiomyoma. Administration of gonadotropin-releasing hormone agonists before UAE is useful in selected patients and is not a contraindication for the procedure. The risk of subsequent re-intervention 5 years after UAE is approximately 10%, which represents an acceptable profile. UAE for adenomyosis is challenging; initial embolization using small particles can achieve better success than that by using larger particles. An intravenous injection of dexamethasone prior to UAE, followed by a patient-controlled analgesia pump and intra-arterial administration of lidocaine after the procedure, are useful techniques to control pain. Dexmedetomidine is an excellent supplemental sedative, showing a fentanyl-sparing effect without causing respiratory depression. UAE for symptomatic leiomyoma is safe and can be an alternative to surgery in most patients with a low risk of re-intervention.

Prognostic value of pre-embolisation MRI features of uterine fibroids in uterine artery embolisation

AIM

To evaluate the prognostic value of pretreatment pelvic magnetic resonance imaging (MRI) features in uterine artery embolisation (UAE) for symptomatic fibroids.

MATERIALS AND METHODS

MRI characteristics of 109 fibroids (≥3 cm) in 70 patients were analysed retrospectively. Imaging was performed 1.8±1.3 (SD) months before and 6.6±1.8 months after UAE. On pretreatment images, signal intensity (SI) of fibroids was compared with that of the myometrium and skeletal muscle on T1- and T2-weighted sequences; the contrast enhancement pattern and localisation of fibroids were also analysed. Fibroid volume reduction (VR) was assessed by control imaging. The numerical analogue quality-of-life score was obtained before and after UAE. Statistical analysis was performed using the Mann-Whitney U-test, Kruskal-Wallis test, and Wilcoxon signed-rank test.

RESULTS

The mean fibroid volume decreased by 51.1±30.8% during the 6.6±1.8 months (p<0.001). Mean quality-of-life score improved by 48.2±27.6 points (p<0.001). The mean VR of submucosal fibroids (82.1±18.5%) was greater than that of intramural (49.4±30.7%) and subserosal (43±28.3%) fibroids (p<0.001 for both). Fibroids that were isointense/hyperintense to myometrium on T2-weighted images showed a better response than hypointense fibroids (63.7±25.8% versus 48.6±31.3%, respectively; p=0.041). On contrast-enhanced images, isointense/hyperintense fibroids showed a better VR than hypointense fibroids (61.3±27.4% versus 47.6±31.6%, respectively; p=0.035). Baseline fibroid volume of <50 cm3 was also associated with favourable imaging outcome (p=0.021). T2 SI compared to skeletal muscle and T1 SI compared to myometrium or skeletal muscle did not show association with VR.

CONCLUSIONS

Localisation, T2 SI, contrast enhancement, and <50 cm3 fibroid volume were associated with better VR; these may help with treatment decisions.

Development of a Model for the Prediction of Treatment Response of Uterine Leiomyomas after Uterine Artery Embolization

Background: Uterine artery embolization (UAE) is one of the minimally-invasive alternatives to hysterectomy for treatment of uterine leiomyomas. There are various factors affecting the outcomes of UAE, but these have only been sporadically studied. Study Objective: To identify factors associated with the efficacy of UAE for the treatment of uterine leiomyoma, and to develop a model for the prediction of treatment response of uterine leiomyomas to UAE. Study design: A retrospective cohort study (Canadian Task Force Classification II-2) Patients: One hundred ninety-eight patients with symptomatic uterine leiomyomas. Intervention: UAE Measurements and Main Results: Among 198 leiomyoma patients who were treated with UAE, 104 who underwent pelvic magnetic resonance imaging (MRI) with diffusion-weighted imaging were selected for developing prediction model. Variables that were statistically significant from the univariate analysis were: location of leiomyoma, total number of lesions, sum of leiomyomas diameters, T2 signal intensity of largest leiomyoma, and T2 leiomyoma:muscle ratio. After a logistic regression analysis, leiomyoma location and T2 signal intensity of the largest leiomyoma were found to be statistically significant variables. Using intramural myomas defined as controls, submucosal leiomyomas showed a greater response to UAE with an odds ratio of 7.6904. The odds ratio of T2 signal intensity with an increase in signal intensity of 10 was 1.093. Using these two variables, we developed a prediction model. The AUC in the prediction model was 0.833, and the AUC in the validation set was 0.791. Conclusion: We identified that submucosal leiomyomas and those leiomyomas that show high signal intensity on T2-weighted imaging will exhibit a greater response to UAE. Prediction models are clinically helpful in selecting UAE as an appropriate treatment option for managing uterine leiomyoma.

Scaled Signal Intensity of Uterine Fibroids on T2-Weighted MR Imaging as a Predictor of the Potential Response to Uterine Fibroid Embolization

PURPOSE

To determine feasibility of scaled signal intensity (SSI) of uterine fibroids on T2-weighted magnetic resonance (MR) images to predict volume reduction rate (VRR) after uterine fibroid embolization (UFE).

MATERIALS AND METHODS

In this retrospective study, 66 premenopausal women underwent UFE. Patients underwent follow-up MR imaging 3 months after UFE. SSI of predominant fibroids was measured on T2-weighted MR images obtained before the procedure by standardizing the mean signal intensity to a 0-to-100 scale, with 0 representing rectus abdominis muscle and 100 representing subcutaneous fat (100) for reference values.

RESULTS

VRR of predominant fibroids was 12.3%-99.0% (mean 53.7%). SSI of predominant fibroids was 0.9-73.6 (mean 24.6). SSI was significantly related to VRR of fibroids (P < .01). The optimal SSI cutoff value to predict VRR > 50% was 18.16 with sensitivity of 78.8% and specificity of 66.7%. The optimal SSI cutoff value to predict VRR < 30% was 14.38 with sensitivity of 75% and specificity of 70.7%.

CONCLUSIONS

SSI of fibroids was significantly related to fibroid VRR after UFE. SSI may be useful in the quantified prediction of volume reduction.

Research of dose-effect relationship parameters of percutaneous microwave ablation for uterine leiomyomas--a quantitative study

Eighty eight patients with 91 uterine leiomyomas who underwent ultrasound-guided percutaneous microwave ablation (PMWA) treatment were prospectively included in the study in order to study the dose-effect relationship parameters (DERP) of PMWA for uterine leiomyomas and its relationship with T2-weighted MR imaging (T2WI). Based on the signal intensity of T2WI, uterine leiomyomas were classified as hypointense, isointense, and hyperintense. During ablation, leiomyomas were treated with quantitative microwave ablation (QMWA) energy of 50 w × 300 s or 60 w × 300 s. After QMWA, contrast-enhanced ultrasound (CEUS) was performed to evaluate DERP. No matter under 50 w × 300 s or 60 w × 300 s, quantitative microwave ablation volume (QMAV) of hyperintense leiomyoma was smaller than that of hypointense and isointense leiomyoma (P<0.016). For hypointense and isointense leiomyoma, QMAV of 60 w × 300 s was larger than that of 50 w × 300 s (P<0.05). DERPs obtained by T2WI can be used to guide the treatment of uterine leiomyoma by PMWA.

Feasibility study on energy prediction of microwave ablation upon uterine adenomyosis and leiomyomas by MRI

OBJECTIVE

To evaluate the feasibility of energy prediction of percutaneous microwave ablation (PMWA) upon uterine leiomyomas and adenomyosis by MRI.

METHODS

63 patients (49 patients with 49 uterine leiomyomas and 14 patients with adenomyosis) who underwent ultrasound-guided PMWA treatment were studied during the period from June 2011 to December 2012. Before PMWA, contrast-enhanced MRI (ceMRI) was performed for all of the patients. Based on the signal intensity (SI) of T2 weighted MRI, uterine leiomyomas were classified as hypointense, isointense and hyperintense. During ablation, the output energy of the microwave was set at 50 W, and T11a microwave antennas were used. ceMRI was performed within 7 days after PMWA treatment. Non-perfused volume and energy required per unit volume were analysed statistically.

RESULTS

When unit volume of lesions was ablated, uterine adenomyosis needed more energy than did uterine leiomyomas, and hyperintense uterine leiomyomas needed more energy than did hypointense pattern.

CONCLUSIONS

MRI SI of uterine leiomyomas and uterine adenomyosis can be used to predict PMWA energy.

ADVANCES IN KNOWLEDGE

The conclusions indicate that MRI SI can be used to perform pre-treatment planning, which will make the treatment more precise.

A case-control study of high-intensity focused ultrasound combined with sonographically guided intratumoral ethanol injection in the treatment of uterine fibroids

OBJECTIVES

The purpose of this study was to explore the feasibility of high-intensity focused ultrasound combined with sonographically guided intratumoral ethanol injection in the treatment of uterine fibroids and to compare its therapeutic effects and potential side effects with those of simple high-intensity focused ultrasound treatment.

METHODS

Forty patients with uterine fibroids from the Department of Ultrasonography in our hospital were randomly divided into 2 groups of the same size: group H, which only underwent high-intensity focused ultrasound treatment; and group H + A, which underwent sonographically guided intratumoral ethanol injection therapy first and then high-intensity focused ultrasound treatment the following day. The treatment times, treatment doses, pain scores, side effects, and therapeutic effect rates of the groups were then recorded and compared.

RESULTS

Both the treatment time and dose of group H + A were significantly less than those of group H, and the differences were statistically significant (P < .05). A lower pain score and fewer side effects were achieved in group H + A, also with statistically significant differences (P < .05). The therapeutic effect rate of group H + A was also higher than that of group H, and the difference was also statistically significant (P < .05).

CONCLUSIONS

In the treatment of uterine fibroids, high-intensity focused ultrasound combined with sonographically guided intratumoral ethanol injection requires less treatment time and a lower dose than simple high-intensity focused ultrasound treatment and significantly reduces the pain and side effects commonly experienced by patients. High-intensity focused ultrasound combined with sonographically guided intratumoral ethanol injection is a feasible, safe, and more effective way to treat patients with uterine fibroids.