Efficacy of ultrasound-guided high-intensity focused ultrasound (USgHIFU) for uterine fibroids: an observational single-center study

Value of multi-modal MRI in predicting the effect of high-intensity focused ultrasound for uterine fibroids

OBJECTIVE

To explore the value of advanced MRI techniques in predicting the effect of high-intensity focused ultrasound (HIFU) on uterine fibroids and to establish a prediction model.

METHODS

This study enrolled 40 patients with 52 uterine fibroids who underwent HIFU at our hospital. All patients were scanned using multiple MRI sequences before HIFU therapy, including non-contrast enhanced MRI, contrast-enhanced MRI, diffusion weighted imaging (DWI), arterial spin labeling (ASL), and T1 mapping. MRI sequences that could predict the HIFU effect were identified, and the predictive performance was evaluated using ROC curves. Univariate and multivariate logistic analyses were employed to investigate independent predictors and establish a prediction model. In addition, we assessed and verified the performance of the model.

RESULTS

Hyperintense on T2 weighted imaging (T2WI), large apparent diffusion coefficient (ADC) values derived from DWI, and high perfusion index derived from ASL were associated with a poor HIFU effect. Univariate and multivariate logistic analyses suggested that uterine position, ADC value and perfusion index were independent predictors for establishing the prediction model. The AUC of the prediction model was 0.939. Both the Hosmer-Lemeshow test and the calibration curve indicated good calibration. The decision curve analysis (DCA) curve showed good clinical benefits, and the leave-one-out cross-validation (LOOCV) revealed that the model had good predictive performance and generalization ability.

CONCLUSION

ADC values and perfusion index are predictors of the effect of HIFU on uterine fibroids. The prediction model including uterine position, ADC value, and perfusion index as predictors has good predictive performance.

Machine learning models for prediction of NPVR ≥80% with HIFU ablation for uterine fibroids

BACKGROUND

Currently high-intensity focused ultrasound (HIFU) is widely used to treat uterine fibroids (UFs). The aim of this study is to develop a machine learning model that can accurately predict the efficacy of HIFU ablation for UFs, assisting the preoperative selection of suitable patients with UFs.

METHODS

This study collected data from 1,000 patients with UFs who underwent ultrasound-guided high-intensity focused ultrasound. The least absolute shrinkage and selection operator (LASSO) regression was used for multidimensional feature screening. Five machine learning algorithms such as logistic regression, random forest, extreme gradient boosting (XGBoost), artificial neural network, and gradient boosting decision tree were utilized to predict ablation efficacy. The efficacy was quantified by the non-perfused volume ratio (NPVR), which was classified into two categories: NPVR <80% and NPVR ≥80%.

RESULTS

The XGBoost model proved to be the most effective, showing the highest AUC of 0.692 (95% CI: 0.622-0.762) in the testing data set. The four key predictors were T2 weighted image, the distance from ventral side of UFs to skin, platelet count, and contrast-enhanced T1 weighted image.

CONCLUSIONS

The machine learning prediction model in this study showed significant potential for accurately predicting the preoperative efficacy of HIFU ablation for UFs. These insights were important for clinicians in the preoperative assessment and selection of patients, which could enhance the precision of treatment planning.

Establishment of a Predictive Model for the Efficacy of High-Intensity Focused Ultrasound in the Treatment of Uterine Fibroids

OBJECTIVES

High-intensity focused ultrasound (HIFU) has demonstrated efficacy as a non-invasive treatment for uterine fibroids, though individual variability exists. This study aims to develop a risk scoring model using clinical and biochemical features to predict HIFU treatment outcomes.

METHODS

This study collected clinical data from patients receiving HIFU treatment, including demographic characteristics, clinical symptoms, treatment information, and biochemical indicators. A risk scoring model was constructed using the random forest analysis method, and its performance was evaluated. Meanwhile, the impact of risk models and other factors on the efficacy of HIFU was evaluated. Furthermore, the interrelationships between the risk model and other factors were explored through interaction analysis. Finally, a nomogram was developed to evaluate its clinical utility.

RESULTS

The risk model, 4 or more treatments, age, and tumor necrosis factor levels were identified as independent influencing factors, with the risk model demonstrating the best performance (area under the curve (AUC) = 0.693). Interaction analysis revealed a significant synergistic effect between the risk model and receiving 4 or more treatments. The nomogram analysis indicated that lower risk scores and fewer treatment sessions were associated with better HIFU treatment outcomes. The receiver operating characteristic curves and calibration curves in both the training and validation sets demonstrated good performance of the nomogram.

CONCLUSIONS

This study successfully constructed a risk scoring model based on clinical features and biochemical indicators, which can effectively predict the efficacy of HIFU treatment for uterine fibroids. There is a significant interaction between the risk model and 4 or more treatments. The constructed nomogram provides strong support for individualized treatment.

Clinical comparison of laparoscopic and open surgical approaches for uterus-preserving myomectomy: a retrospective analysis on patient-reported outcome, postoperative morbidity and pregnancy outcomes

PURPOSE

Uterine fibroids pose clinical challenges due to varied symptoms and impact on fertility. Aim of this research is to compare open and laparoscopic myomectomy, with focus on evaluating their effects on patients' quality of life and analyzing their implications for pregnancy outcomes.

METHODS

This retrospective study compares open and laparoscopic myomectomy outcomes in 168 patients treated October 2017 and July 2023. Preoperative characteristics and postoperative outcomes in terms of symptoms and pregnancy outcomes were examined.

RESULTS

The patient cohort comprised patients with a high symptom burden. Only 51.2% expressing a desire for future pregnancies, highlighting diverse motivations for uterus-preservation. No significant differences were observed in preoperative symptoms. Larger and multiple myomas were associated with a higher likelihood of laparotomy. Recurrence rates were lower after laparoscopy (10.2% vs. 23.8%, p = 0.02). Cesarean section recommendations were more frequent post-laparotomy group (36.6% vs. 86.6%, p = 0.000). Morbidities and satisfaction showed no significant differences between approaches, with slightly better bleeding improvement after laparotomy. Despite similar pregnancy outcomes, a high proportion of patients did not conceive postoperatively (75.4%). Among patients who became pregnant postoperatively (n = 31), most patients conceived after one year or more, with no dependence on the surgical approach (p = 0.227).

CONCLUSION

Both open and laparoscopic myomectomy surgeries showed high patient satisfaction, symptom alleviation, and comparable pregnancy results. A preference emerged for laparoscopy in terms of cesarean section recommendations and recurrence risk. Laparoscopic procedures tended to offer higher operative satisfaction and fewer complications. The study emphasized the complexity of therapeutic decision-making.

Ablation of symptomatic uterine fibroids with the Mirabilis system for rapid noninvasive ultrasound-guided high-intensity focused ultrasound (HIFU): a prospective observational clinical study

OBJECTIVES

Uterine fibroids often lead to symptoms that negatively impact health-related quality of life (HRQOL). High-intensity focused ultrasound (HIFU) has emerged as a promising noninvasive treatment for reducing fibroid size and symptoms. The Mirabilis system for ultrasound (US)-guided HIFU introduces a novel technique known as 'shell ablation'. This study evaluates the feasibility and efficacy of Mirabilis in a clinical setting, focusing on clinical outcomes.

MATERIALS AND METHODS

Sixteen patients with 23 uterine fibroids were treated with the Mirabilis system. Follow-up assessments included US and MRI at baseline, 6 weeks, 3, 6 and 9 months, and 1 year after HIFU. Changes in symptoms and QOL were evaluated using the Uterine Fibroid Symptom and HRQOL Questionnaire.

RESULTS

A significant reduction in fibroid volume was observed after HIFU (baseline 182.1 ± 49.3 ml; 1 year: 76.0 ± 37.9 ml, p < 0.001). The symptom severity score significantly declined (baseline 57.2 ± 3.8; 1 year: 30.2 ± 4.9, p < 0.001), correlating with a significant improvement in HRQOL (baseline 47.0 ± 3.9, 1 year: 71.8 ± 5.3, p < 0.001).

CONCLUSION

HIFU with the portable Mirabilis system is a feasible and safe noninvasive treatment for symptomatic uterine fibroids in an outpatient setting. This approach allows efficient and rapid ablation even for large fibroids, significantly reducing fibroid volume and symptoms.

MRI assessment of sacral injury location and analysis of influencing factors after high-intensity focused ultrasound ablation for patients with uterine fibroids

Purpose

Exploration of the location of sacral injuries following ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation for uterine fibroids and analysis of its influencing factors.

Methods

A retrospective analysis was conducted on 663 patients with uterine fibroids treated by USgHIFU ablation. Patients with vertebral injuries were identified based on postoperative MRI images, with specific locations of the injuries documented. Additionally, the condition of muscle damage around the vertebral body was assessed. Patients were divided into Upper group and Lower group based on the location of vertebral injuries. Univariate and multivariate logistic regression analyses were conducted to identify the influencing factors. The χ2 test was used to explore the relationship between the location of vertebral injuries and postoperative clinical adverse events, as well as muscle damage.

Results

Postoperative MRI examinations revealed that 42.3% (281/663) of the patients experienced vertebral injuries, which were localized to the range from L5 to S5. The injuries from L5 to S2 were classified as Upper group, accounting for 45.2% (127/281), while those from S3 to S5 were classified as Lower group, accounting for 54.8% (154/281). Multivariate analysis revealed that the distance from the ventral side of the fibroid to the abdominal wall skin, uterine position, and T2WI signal intensity were positively correlated with the location of sacral injuries (p < 0.05). Additionally, the location of sacral injuries was significantly associated with the occurrence of postoperative sacrococcygeal pain (p < 0.05). 162 patients (57.6%) with sacral injury were accompanied by piriformis and gluteus maximus muscle injuries, with piriformis injury accounting for 95.06%. The location of sacral injury was significantly correlated with piriformis injury (p < 0.05).

Conclusion

Postoperative MRI images of some patients with uterine fibroids treated with USgHIFU ablation show vertebral and surrounding muscle injuries, mainly involving sacrum and piriformis. For those with a retroverted uterus, a large distance between the ventral side of the fibroid and the abdominal wall, or fibroids exhibiting high signals on T2-weighted images (T2WI), the location of postoperative sacral injuries tends to be more inferior. Additionally, these patients face an increased risk of concurrent piriformis injury and a higher likelihood of experiencing sacrococcygeal pain.

Progress in High Intensity Focused Ultrasound Ablation for Fertility Preservation Therapy of Uterine Fibroids and Adenomyosis

High intensity focused ultrasound (HIFU) is an effective and safe non-invasive treatment method, widely used in the treatment of uterine fibroids and adenomyosis in the field of gynecology. The side effects in HIFU is low in incidence and mild. HIFU can significantly alleviate the symptoms of patients, reduce lesion volumes, improve quality of life, and has good cost-effectiveness. HIFU can accurately ablate the uterine fibroids and adenomyosis lesions, without destroying normal myometrium and endometrium, and thus HIFU is a promising alternative to myomectomy in uterine fibroids patients with fertility desire. Several studies have shown that in terms of ovarian endocrine function protection, HIFU treatment is superior to uterine artery embolization, and similar to myomectomy. Existing limited researches show that patients with uterine fibroids have a favorable pregnancy rate and live birth rate, as well as a lower natural abortion rate after HIFU treatment. Pregnancy rate after HIFU treatment for uterine fibroids is not lower than myomectomy, and higher than uterine artery embolization. HIFU may have significant advantages in shortening pregnancy interval compared with myomectomy. However, the proportion of cesarean section delivery after HIFU treatment is relatively high, and gestational uterine rupture after HIFU treatment exist in literature. Higher quality clinical data is needed to confirm the pregnancy outcomes and safety after HIFU treatment in future.

The value of multi-parameter radiomics combined with imaging features in predicting the therapeutic efficacy of HIFU treatment for uterine fibroids

Objectives

To evaluate the effectiveness of high-intensity focused ultrasound (HIFU) therapy for treating uterine fibroids by utilizing multi-sequence magnetic resonance imaging radiomic models.

Methods

One hundred and fifty patients in our hospital were randomly divided into a training cohort (n=120) and an internal test cohort (n=30), and forty-five patients from another hospital serving as an external test cohort. Radiomics features of uterine fibroids were extracted and selected based on preoperative T2-weighted imaging fat suppression(T2WI-FS)and contrast-enhanced T1WI(CE-T1WI)images, and logistic regression was used to develop the T2WI-FS, CE-T1WI, and combined T2WI-FS + CE-T1WI models, along with the radiomics-clinical model integrating radiomics features with imaging characteristics. The performance and clinical applicability of each model were assessed through receiver operating characteristic (ROC) curve, decision curve analysis (DCA), as well as Network Readiness Index (NRI) and Integrated Discrimination Index (IDI).

Results

The AUC values of the radiomics-clinical model and the T2WI-FS + CE-T1WI model were the highest. In the training cohort, the radiomics-clinical model showed higher AUC values than the T2WI-FS + CE-T1WI model, while in the internal and external testing cohorts, the AUC values of the T2WI-FS + CE-T1WI model were higher than that of the radiomics-clinical model. DCA further demonstrated that these two models achieved the greatest net benefit. NRI and IDI analyses suggested that the T2WI-FS + CE-T1WI model had higher clinical utility.

Conclusions

Both the T2WI-FS + CE-T1WI model and the radiomics-clinical model demonstrate higher predictive value and larger net benefit compared to other models.

A systematic review of the side effects of high-intensity focused ultrasound ablation of uterine fibroids

Background

A new intervention called high-intensity focused ultrasound (HIFU) targets fibroids with high-intensity ultrasound pulses using ultrasound probes. This noninvasive method, which can be carried out with either magnetic resonance imaging or ultrasound guidance, results in immediate coagulated necrosis within a clearly defined area a few millimeters in diameter.

Methods

This systematic review evaluated the safety of HIFU in the treatment of uterine fibroids regardless of site or size. We specifically aimed to determine the incidence of side effects that can occur during and after HIFU. We searched the PubMed, Scopus, ScienceDirect, and Mendeley archive using only the terms HIFU and fibroid. After identifying 1077 studies of different types from 2014 to March 2024, 300 studies were screened and 60 included.

Results

According to Society of Interventional Radiology guidelines, class A adverse events (AEs) showed no significant results, and individuals with these AEs required no treatment and had no long-term consequences. Similarly, there were no class B significant results. However, 3943 of 10,204 patients (38%) complained of lower abdominal pain after the procedure, a class B AE, which resolved by analgesics. Further, 153 of 24,700 patients (0.6%) had skin burns, blisters, or nodules, and these issues resolved with conservative treatment. Additionally, 74 of 23,741 patients (0.3%) had hematuria; 882 of 5970 patients (14.7%) had abnormal vaginal discharge; 414 of 23,449 (1.7%) had vaginal bleeding; and 267 of 7598 (3.5%) had leg paresthesia. Major AEs (class C and D) were almost nonexistent, and the incidence of death in our study was zero.

Conclusion

HIFU ablation of uterine fibroids is generally safe, causing mostly mild side effects and very few severe complications. The relative safety of HIFU compared to other minimally invasive techniques, such as uterine artery embolization, still needs further evaluation.

Predicting the efficacy of high-intensity focused ultrasound (HIFU) ablation for uterine leiomyomas based on DTI indicators and imaging features

PURPOSE

To predict the efficacy of high-intensity focused ultrasound (HIFU) ablation for uterine leiomyomas based on diffusion tensor imaging (DTI) indicators and imaging features.

METHODS

Sixty-two patients with 85 uterine leiomyomas were consecutively enrolled in this retrospective study and underwent DTI scanning before HIFU treatment. Based on whether the non-perfused volume ratio (NPVR) was greater than 70%, all patients were assigned to sufficient ablation (NPVR ≥ 70%) or insufficient ablation (NPVR < 70%) groups. The selected DTI indicators and imaging features were incorporated to construct a combined model. The predictive performance of DTI indicators and the combined model were assessed using receiver operating characteristic (ROC) curves.

RESULTS

There were 42 leiomyomas in the sufficient ablation group (NPVR ≥ 70%) and 43 leiomyomas in the insufficient ablation group (NPVR < 70%). The fractional anisotropy (FA) and relative anisotropy (RA) values were higher in the sufficient ablation group than in the insufficient ablation group (p < 0.05). Conversely, the volume ratio (VR) and mean diffusivity (MD) values were lower in the sufficient ablation group than those in the insufficient ablation group (p < 0.05). Notably, the combined model composed of the RA and enhancement degree values had high predictive efficiency, with an AUC of 0.915. The combined model demonstrated higher predictive performance than FA and MD alone (p = 0.032 and p < 0.001, respectively) but showed no significant improvement compared with RA and VR (p > 0.05).

CONCLUSION

DTI indicators, especially the combined model incorporating DTI indicators and imaging features, can be a promising imaging tool to assist clinicians in predicting HIFU efficacy for uterine leiomyomas.

Combination of HIFU with sulfur hexafluoride microbubbles in the treatment of solitary uterine fibroids: a systematic review and meta-analysis

OBJECTIVES

To assess the efficacy and safety of sulfur hexafluoride microbubbles on ultrasound-guided high-intensity focused ultrasound (HIFU) ablation of uterine fibroids.

METHODS

Studies that compared HIFU-microbubble combination with HIFU-only in patients with uterine fibroids were searched from inception to April 2022. The standardized mean difference (SMD) or relative risk (RR) with 95% confidence interval (CI) for different outcome parameters was calculated.

RESULTS

Seven studies were included, with a total of 901 patients (519 in the combination group and 382 in the HIFU-only group). The energy consumption for treating 1 cm3 of the lesion in the combination group was less than that in the HIFU-only group [SMD =  - 2.19, 95%CI (- 3.81, - 0.57), p = 0.008]. The use of microbubbles was associated with shortening the duration of the treatment and sonication [SMD =  - 2.60, 95%CI (- 4.09, - 1.10), p = 0.0007; SMD =  - 2.11, 95%CI (- 3.30, - 0.92), p = 0.0005]. The rates of significant greyscale changes during HIFU were greater in the combination group, as well as the increase of non-perfused volume ratio [RR = 1.26, 95%CI (1.04, 1.54), p = 0.02; SMD = 0.32, 95%CI (0.03, 0.61), p = 0.03]. The average sonication durations to reach significant greyscale changes and for ablating 1 cm3 of the fibroid lesion were shorter in the combination group [SMD =  - 1.24, 95%CI (- 2.02, - 0.45), p = 0.002; SMD =  - 0.22, 95%CI (- 0.42, - 0.02), p = 0.03]. The two groups had similar post-HIFU adverse effects, while the combination group had fewer intraprocedural adverse events like abdominal pain, sacrum pain, and leg pain.

CONCLUSIONS

Sulfur hexafluoride microbubbles can be safely used to enhance and accelerate the ablation effects of HIFU in the treatment of uterine fibroids.

CLINICAL RELEVANCE STATEMENT

The combination of HIFU with sulfur hexafluoride microbubbles offers a promising non-invasive treatment option for patients with uterine fibroids.

KEY POINTS

• Sulfur hexafluoride microbubbles combined with ultrasound-guided high-intensity focused ultrasound (USgHIFU) has potential advantages in the treatment of uterine fibroids. • Sulfur hexafluoride microbubbles not only enhance the effects of USgHIFU treatment for uterine fibroids but also shorten its duration. • Sulfur hexafluoride microbubbles do not increase the incidence of USgHIFU-related adverse events in the treatment of uterine fibroids.

Prediction of non-perfusion volume ratio for uterine fibroids treated with ultrasound-guided high-intensity focused ultrasound based on MRI radiomics combined with clinical parameters

BACKGROUND

Prediction of non-perfusion volume ratio (NPVR) is critical in selecting patients with uterine fibroids who will potentially benefit from ultrasound-guided high-intensity focused ultrasound (HIFU) treatment, as it reduces the risk of treatment failure. The purpose of this study is to construct an optimal model for predicting NPVR based on T2-weighted magnetic resonance imaging (T2MRI) radiomics features combined with clinical parameters by machine learning.

MATERIALS AND METHODS

This retrospective study was conducted among 223 patients diagnosed with uterine fibroids from two centers. The patients from one center were allocated to a training cohort (n = 122) and an internal test cohort (n = 46), and the data from the other center (n = 55) was used as an external test cohort. The least absolute shrinkage and selection operator (LASSO) algorithm was employed for feature selection in the training cohort. The support vector machine (SVM) was adopted to construct a radiomics model, a clinical model, and a radiomics-clinical model for NPVR prediction, respectively. The area under the curve (AUC) and the decision curve analysis (DCA) were performed to evaluate the predictive validity and the clinical usefulness of the model, respectively.

RESULTS

A total of 851 radiomic features were extracted from T2MRI, of which seven radiomics features were screened for NPVR prediction-related radiomics features. The radiomics-clinical model combining radiomics features and clinical parameters showed the best predictive performance in both the internal (AUC = 0.824, 95% CI 0.693-0.954) and external (AUC = 0.773, 95% CI 0.647-0.902) test cohorts, and the DCA also suggested the radiomics-clinical model had the highest net benefit.

CONCLUSIONS

The radiomics-clinical model could be applied to the NPVR prediction of patients with uterine fibroids treated by HIFU to provide an objective and effective method for selecting potential patients who would benefit from the treatment mostly.

Study Protocol of a Prospective, Monocentric, Single-Arm Study Investigating the Safety and Efficacy of Local Ablation of Symptomatic Uterine Fibroids with US-Guided High-Intensity Focused Ultrasound (HIFU)

Uterine fibroids are the most common benign tumors of the uterus. Approximately 20-50% of women with myomas experience a variety of symptoms such as vaginal bleeding, abdominal pain, pelvic pain and pressure, and urological problems, possibly interfering with fertility and pregnancy. Although surgery remains the standard treatment option for fibroids, non-invasive therapeutic options, such as high-intensity focused ultrasound (HIFU), have emerged over the last dec ade. During HIFU, ultrasound is focused on the target tissue causing coagulation necrosis. HIFU has, meanwhile, become an established method for treating uterine fibroids in many countries. Clinical data have shown that it effectively alleviates fibroid-related symptoms and reduces fibroid size with a very low rate of side effects. However, there is a lack of data on how this treatment affects laboratory parameters and structural features of uterine tissue. As our center is the only one in German-speaking countries where ultrasound-guided HIFU technology is currently established, the aim of this prospective, monocentric, single-arm trial is not only to evaluate the safety and efficacy of local US-guided HIFU in symptomatic uterine fibroid patients according to GCP standards but also to explore its effects on blood parameters and the structural integrity of uterine tissue using elastographic methods.

Changes in Pelvic Floor Symptoms After Procedural Interventions for Uterine Leiomyomas: A Systematic Review

OBJECTIVE

To conduct a systematic review to evaluate the effect of procedural interventions for leiomyomas on pelvic floor symptoms.

DATA SOURCES

PubMed, EMBASE, and ClinicalTrials.gov were searched from inception to January 12, 2023, searching for leiomyoma procedures and pelvic floor disorders and symptoms, restricted to primary study designs in humans.

METHODS OF STUDY SELECTION

Double independent screening for studies of any study design in all languages that reported pelvic floor symptoms before and after surgical (hysterectomy, myomectomy, radiofrequency volumetric thermal ablation) or radiologic (uterine artery embolization, magnetic resonance-guided focused ultrasonography, high-intensity focused ultrasonography) procedures for management of uterine leiomyomas. Data were extracted, with risk-of-bias assessment and review by a second researcher. Random effects model meta-analyses were conducted, as feasible.

TABULATION, INTEGRATION, AND RESULTS

Six randomized controlled trials, one nonrandomized comparative study, and 25 single-group studies met criteria. The overall quality of the studies was moderate. Only six studies, reporting various outcomes, directly compared two procedures for leiomyomas. Across studies, leiomyoma procedures were associated with decreased symptom distress per the UDI-6 (Urinary Distress Inventory, Short Form) (summary mean change -18.7, 95% CI -25.9 to -11.5; six studies) and improved quality of life per the IIQ-7 (Incontinence Impact Questionnaire, Short Form) (summary mean change -10.7, 95% CI -15.8 to -5.6; six studies). There was a wide range of resolution of urinary symptoms after procedural interventions (7.6-100%), and this varied over time. Urinary symptoms improved in 19.0-87.5% of patients, and the definitions for improvement varied between studies. Bowel symptoms were inconsistently reported in the literature.

CONCLUSION

Urinary symptoms improved after procedural interventions for uterine leiomyomas, although there is high heterogeneity among studies and few data on long-term outcomes or comparing different procedures.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42021272678.

Deep learning enables automated MRI-based estimation of uterine volume also in patients with uterine fibroids undergoing high-intensity focused ultrasound therapy

BACKGROUND

High-intensity focused ultrasound (HIFU) is used for the treatment of symptomatic leiomyomas. We aim to automate uterine volumetry for tracking changes after therapy with a 3D deep learning approach.

METHODS

A 3D nnU-Net model in the default setting and in a modified version including convolutional block attention modules (CBAMs) was developed on 3D T2-weighted MRI scans. Uterine segmentation was performed in 44 patients with routine pelvic MRI (standard group) and 56 patients with uterine fibroids undergoing ultrasound-guided HIFU therapy (HIFU group). Here, preHIFU scans (n = 56), postHIFU imaging maximum one day after HIFU (n = 54), and the last available follow-up examination (n = 53, days after HIFU: 420 ± 377) were included. The training was performed on 80% of the data with fivefold cross-validation. The remaining data were used as a hold-out test set. Ground truth was generated by a board-certified radiologist and a radiology resident. For the assessment of inter-reader agreement, all preHIFU examinations were segmented independently by both.

RESULTS

High segmentation performance was already observed for the default 3D nnU-Net (mean Dice score = 0.95 ± 0.05) on the validation sets. Since the CBAM nnU-Net showed no significant benefit, the less complex default model was applied to the hold-out test set, which resulted in accurate uterus segmentation (Dice scores: standard group 0.92 ± 0.07; HIFU group 0.96 ± 0.02), which was comparable to the agreement between the two readers.

CONCLUSIONS

This study presents a method for automatic uterus segmentation which allows a fast and consistent assessment of uterine volume. Therefore, this method could be used in the clinical setting for objective assessment of therapeutic response to HIFU therapy.

Prediction of postoperative reintervention risk for uterine fibroids using clinical-imaging features and T2WI radiomics before high-intensity focused ultrasound ablation

OBJECTIVE

To predict the risk of postoperative reintervention for uterine fibroids using clinical-imaging features and T2WI radiomics before high-intensity focused ultrasound (HIFU) ablation.

METHODS

Among patients with uterine fibroids treated with HIFU from 2019 to 2021, 180 were selected per the inclusion and exclusion criteria (42 reintervention and 138 non-reintervention). All patients were randomly assigned to either the training (n = 125) or validation (n = 55) cohorts. Multivariate analysis was used to determine independent clinical-imaging features of reintervention risk. The Relief and LASSO algorithm were used to select optimal radiomics features. Random forest was used to construct the clinical-imaging model based on independent clinical-imaging features, the radiomics model based on optimal radiomics features, and the combined model incorporating the above features. An independent test cohort of 45 patients with uterine fibroids tested these models. The integrated discrimination index (IDI) was used to compare the discrimination performance of these models.

RESULTS

Age (p < .001), fibroid volume (p = .001) and fibroid enhancement degree (p = .001) were identified as independent clinical-imaging features. The combined model had AUCs of 0.821 (95% CI: 0.712-0.931) and 0.818 (95% CI: 0.694-0.943) in the validation and independent test cohorts, respectively. The predictive performance of the combined model was 27.8% (independent test cohort, p < .001) and 29.5% (independent test cohort, p = .001) better than the clinical-imaging and radiomics models, respectively.

CONCLUSION

The combined model can effectively predict the risk of postoperative reintervention for uterine fibroids before HIFU ablation. It is expected to help clinicians to develop accurate, personalized treatment and management plans. Future studies will need to be prospectively validated.

Post treatment and 3 month contrast enhanced MRI findings following HIFU of submucosal fibroids: a retrospective study

PURPOSE

This study used contrast-enhanced MRI (CE-MRI) examination to assess the efficacy of high-intensity focused ultrasound (HIFU) for submucosal fibroids.

METHODS

A total of 81 submucosal fibroids, including 33 cases of type 1, 29 cases of type 2, and 19 cases of type 2-5, treated by HIFU were retrospectively reviewed. CE-MRI was performed in all cases immediately after HIFU, the non-perfused volume ratio (NPVR) and the degree of endometrial impairment were recorded. Thereafter, CE-MRI was repeated in all cases after three months, and the change of fibroid volume shrinkage rate (FVSR), NPVR and the degree of endometrial impairment were recorded.

RESULTS

The immediate NPVR was 86.4 ± 19.3% in type 1, 90.0 ± 13.3% in type 2 and 90.3 ± 7.2% in type 2-5. Among 81 fibroids, grades 0, 1, 2 and 3 endometrial impairments were observed in 38.3%, 16.1%, 14.8% and 30.9%, respectively. Three months later, NPVR was 68.0 ± 36.4% in type 1, 74.3 ± 27.7% in type 2 and 85.0 ± 16.1% in type 2-5. Grades 0, 1, 2 and 3 endometrial impairments were observed in 64.2%, 23.5%, 9.9% and 2.4%.FVSR was 49.0 ± 1.3% in type 1, 39.6 ± 1.7% in type 2 and 37.2 ± 2.1% in type 2-5. The FVSR in submucosal fibroid type 1 was superior to type 2 and type 2-5 (p < 0.05). The NPVR of submucosal fibroids in type 2-5 were higher than type 1 (p < 0.05) .There was no difference among different types of submucosal fibroids in endometrial impairment (p > 0.05) three months after HIFU.

CONCLUSIONS

At three months after HIFU, FVSR was better for submucosal fibroid type 1 than for type 2 and type 2-5. And there was no difference in endometrial impairment among the different types of submucosal fibroid groups.

Development and validation of a combined model based on dual-sequence MRI radiomics for predicting the efficacy of high-intensity focused ultrasound ablation for hysteromyoma

OBJECTIVES

To determine the value of dual-sequence magnetic resonance imaging (MRI)-based radiomics in predicting the efficacy of high-intensity focused ultrasound (HIFU) ablation for hysteromyoma.

METHODS

A total of 142 patients with 172 hysteromyomas (95 hysteromyomas from the sufficient ablation group, and 77 hysteromyomas from the insufficient ablation group) were enrolled in the study. The clinical-radiological model was constructed with independent clinical-radiological risk factors, the radiomics model was constructed based on the optimal radiomics features of hysteromyoma from dual sequences, and the two groups of features were incorporated to construct the combined model. A fivefold cross validation procedure was adopted to validate these models. A nomogram was constructed, applying the combined model in the training cohort. The models were assessed with receiver operating characteristic (ROC) curves and integrated discrimination improvement (IDI). An independent test cohort comprising 40 patients was used to evaluate the performance of the optimal model.

RESULTS

Among the three models, the average areas under the ROC curves (AUC) of the radiomics model and combined model were 0.803 (95% confidence interval (CI): 0.726-0.881) and 0.841 (95% CI: 0.772-0.909), which were better than the clinical-radiological model in the training cohort. The IDI showed that the combined model had the best prediction accuracy. The combined model also showed good discrimination in both the validation cohort (AUC = 0.834) and the independent test cohort (AUC = 0.801).

CONCLUSION

The combined model based on the dual-sequence MRI radiomics is the most promising tool from our study to assist clinicians in predicting HIFU ablation efficacy.

Rational Nanomedicine Design Enhances Clinically Physical Treatment-Inspired or Combined Immunotherapy

Independent of tumor type and non-invasive or minimally-invasive feature, current physical treatments including ultrasound therapy, microwave ablation (MWA), and radiofrequency ablation (RFA) are widely used as the local treatment methods in clinics for directly killing tumors and activating systematic immune responses. However, the activated immune responses are inadequate and incompetent for tumor recession, and the incomplete thermal ablation even aggravates the immunosuppressive tumor microenvironment (ITM), resulting in the intractable tumor recurrence and metastasis. Intriguingly, nanomedicine provides a powerful platform as they can elevate energy utilization efficiency and augment oncolytic effects for mitigating ITM and potentiating the systematic immune responses. Especially after combining with clinical immunotherapy, the anti-tumor killing effect by activating or enhancing the human anti-tumor immune system is reached, enabling the effective prevention against tumor recurrence and metastasis. This review systematically introduces the cutting-edge progress and direction of nanobiotechnologies and their corresponding nanomaterials. Moreover, the enhanced physical treatment efficiency against tumor progression, relapse, and metastasis via activating or potentiating the autologous immunity or combining with exogenous immunotherapeutic agents is exemplified, and their rationales are analyzed. This review offers general guidance or directions to enhance clinical physical treatment from the perspectives of immunity activation or magnification.

Factors influencing magnetic resonance imaging finding of endopelvic fascial edema after ultrasound-guided high-intensity focused ultrasound ablation of uterine fibroids

OBJECTIVE

Investigate the relationships between endopelvic fascial edema and its influencing factors after ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation of uterine fibroids.

METHODS

This retrospective study included 688 women with uterine fibroids treated by USgHIFU; based on post-treatment MRI, the patients were divided into two groups: endopelvic fascial edema group and nonedema group. The specific location of fascial edema of each patient was also recorded. Fascial edema and fibroid features and treatment parameters were set as the dependent and independent variables, respectively, and the correlations were studied using univariate and multivariate analyses. The relationship between the pain-related adverse events and location of fascial edema was analyzed by χ² and fisher's exact tests.

RESULTS

Edema and nonedema groups had 556 and 112 patients, respectively. Among the edema patients, posterior fascial edema incidence was the highest. Multifactorial analysis showed that the energy efficiency factor (EEF), fibroid location, and enhancement type were positively associated with endopelvic fascial edema (p < 0.05), while the distance from dorsal surface of the fibroid to sacrum was negatively correlated (p < 0.001). Patients with anterior, posterior and perirectal, and right lateral fascial edemas were associated with lower abdominal pain, sacrococcygeal pain, and leg numbness/pain, respectively.

CONCLUSION

Post-USgHIFU ablation, patients were prone to developing endopelvic fascial edema, and some of them experienced pain-related adverse events. The fibroid location, its types of contrast enhancement, the distance from the dorsal surface of the fibroid to the sacrum, and EEF were the influencing factors resulting in the endopelvic fascial edema after USgHIFU ablation.

Epigenomic and enhancer dysregulation in uterine leiomyomas

BACKGROUND

Uterine leiomyomas, also known as uterine fibroids or myomas, are the most common benign gynecological tumors and are found in women of reproductive and postmenopausal age. There is an exceptionally high prevalence of this tumor in women by the age of 50 years. Black women are particularly affected, with an increased incidence, earlier age of onset, larger and faster growing fibroids and greater severity of symptoms as compared to White women. Although advances in identifying genetic and environmental factors to delineate these fibroids have already been made, only recently has the role of epigenomics in the pathogenesis of this disease been considered.

OBJECTIVE AND RATIONALE

Over recent years, studies have identified multiple epigenomic aberrations that may contribute to leiomyoma development and growth. This review will focus on the most recent discoveries in three categories of epigenomic changes found in uterine fibroids, namely aberrant DNA methylation, histone tail modifications and histone variant exchange, and their translation into altered target gene architecture and transcriptional outcome. The findings demonstrating how the altered 3D shape of the enhancer can regulate gene expression from millions of base pairs away will be discussed. Additionally, translational implications of these discoveries and potential roadblocks in leiomyoma treatment will be addressed.

SEARCH METHODS

A comprehensive PubMed search was performed to identify published articles containing keywords relevant to the focus of the review, such as: uterine leiomyoma, uterine fibroids, epigenetic alterations, epigenomics, stem cells, chromatin modifications, extracellular matrix [ECM] organization, DNA methylation, enhancer, histone post-translational modifications and dysregulated gene expression. Articles until September 2021 were explored and evaluated to identify relevant updates in the field. Most of the articles focused on in the discussion were published between 2015 and 2021, although some key discoveries made before 2015 were included for background information and foundational purposes. We apologize to the authors whose work was not included because of space restrictions or inadvertent omission.

OUTCOMES

Chemical alterations to the DNA structure and of nucleosomal histones, without changing the underlying DNA sequence, have now been implicated in the phenotypic manifestation of uterine leiomyomas. Genome-wide DNA methylation analysis has revealed subsets of either suppressed or overexpressed genes accompanied by aberrant promoter methylation. Furthermore, differential promoter access resulting from altered 3D chromatin structure and histone modifications plays a role in regulating transcription of key genes thought to be involved in leiomyoma etiology. The dysregulated genes function in tumor suppression, apoptosis, angiogenesis, ECM formation, a variety of cancer-related signaling pathways and stem cell differentiation. Aberrant DNA methylation or histone modification is also observed in altering enhancer architecture, which leads to changes in enhancer-promoter contact strength, producing novel explanations for the overexpression of high mobility group AT-hook 2 and gene dysregulation found in mediator complex subunit 12 mutant fibroids. While many molecular mechanisms and epigenomic features have been investigated, the basis for the racial disparity observed among those in the Black population remains unclear.

WIDER IMPLICATIONS

A comprehensive understanding of the exact pathogenesis of uterine leiomyoma is lacking and requires attention as it can provide clues for prevention and viable non-surgical treatment. These findings will widen our knowledge of the role epigenomics plays in the mechanisms related to uterine leiomyoma development and highlight novel approaches for the prevention and identification of epigenome targets for long-term non-invasive treatment options of this significantly common disease.