Multidisciplinary management to optimize outcome of ultrasound-guided high-intensity focused ultrasound (HIFU) in patients with uterine fibroids

Ultrasound-guided microwave, radiofrequency, and high intensity focused ultrasound (HIFU) ablation in treating uterine leiomyoma: A systemic review and meta-analysis of retrospective studies

To retrospectively evaluate the efficacy and safety of ultrasound-guided microwave (MWA), radiofrequency (RF), and high-intensity focused ultrasound (HIFU) ablation in the treatment of uterine leiomyoma and to provide a suggestion for the selection of clinical treatment of uterine leiomyoma. The retrospective cohort studies on the efficacy of high-intensity focused ultrasound in treating uterine leiomyoma was collected through a literature search in Pubmed, Embase, Cochrane library, Scopus, and Web of Science, and selected according to the specified inclusion criteria and exclusion criteria. Evaluate the study quality, extract relevant data, and RevMan 5.4.1 was used to conduct this meta-analysis. Compared with HIFU therapy, the complete or partial ablation rate and recurrence rate of uterine leiomyoma treated with RFA/MWA were statistically different (P < 0.05). Compared with RF, the overall efficacy of HIFU in treating uterine leiomyoma was not as good as that of RF. There was no significant difference between the RFA therapy and the MWA. HIFU still has mild and short-term complications, such as abdominal pain, bloody vaginal discharge, sacral pain, and fever. Although myomectomy is usually the first choice for uterine preservation, RFA/MWA and HIFU have also been shown to relieve clinical symptoms significantly, shorten treatment time, reduce complications, and improve prognosis.

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.

High-intensity focused ultrasound in adenomyosis treatment: Insights on safety, efficacy, and reproductive prospects

The management of adenomyosis has undergone significant evolution, moving from traditional surgical interventions like hysterectomy to more conservative methods aimed at preserving fertility. Essential roles have been played by uterine-sparing surgeries and uterine artery embolization. Despite these advancements, there is a growing interest in less invasive alternatives. This review delves into the potential of high-intensity focused ultrasound (HIFU). HIFU employs focused ultrasound waves for precise ablation of adenomyotic lesions. The review conducts a thorough analysis of HIFU principles, safety, efficacy, and its possible synergies with other therapies. HIFU seems to be effective for adenomyosis treatment, demonstrating a favorable adverse effect profile and suitability for fertility preservation. Combining HIFU with hormonal treatment appears to enhance long-term symptom control, presenting a promising and comprehensive approach for managing adenomyosis. The goal of this article is to develop a comprehensive understanding of HIFU's role in contemporary adenomyosis management and to explore areas requiring further research.

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.

Reproductive and Obstetric Outcomes after UAE, HIFU, and TFA of Uterine Fibroids: Systematic Review and Meta-Analysis

Novel treatment options for uterine fibroids, such as uterine artery embolization (UAE), ultrasound-guided and magnetic resonance-guided high-intensity focused ultrasound (USgHIFU and MRgHIFU), and transcervical radiofrequency ablation (TFA) methods, are widely used in clinical practice. This systematic review and meta-analysis (CRD42022297312) aims to assess and compare reproductive and obstetric outcomes in women who underwent these minimally invasive approaches for uterine fibroids. The search was performed in PubMed, Google Scholar, ScienceDirect, Cochrane Library, Scopus, Web of Science and Embase. Risk of bias was assessed using the Newcastle-Ottawa Scale (NOS) and Cochrane guidelines. The articles were selected to meet the following eligibility criteria: (1) research article, (2) human subject research, and (3) the study of pregnancy outcomes after the treatment of uterine fibroids by either one of three methods-UAE, HIFU, and TFA. The analysis of 25 eligible original articles shows a similar rate of live births for UAE, USgHIFU, MRgHIFU, and TFA (70.8%, 73.5%, 70%, and 75%, respectively). The number of pregnancies varied considerably among these studies, as well as the mean age of pregnant women. However, the results of pregnancy outcomes for TFA are insufficient to draw firm conclusions, since only 24 women became pregnant in these studies, resulting in three live births. The miscarriage rate was highest in the UAE group (19.2%). USgHIFU was associated with a higher rate of placental abnormalities compared to UAE (2.8% vs. 1.6%). The pooled estimate of pregnancies was 17.31% to 44.52% after UAE, 18.69% to 78.53% after HIFU, and 2.09% to 7.63% after TFA. The available evidence confirmed that these minimally invasive uterine-sparing treatment options for uterine fibroids are a good approach for patients wishing to preserve their fertility, with comparable reproductive and obstetric outcomes among the different techniques.

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.

On-demand regulation and enhancement of the nucleation in acoustic droplet vaporization using dual-frequency focused ultrasound

Acoustic droplet vaporization (ADV) plays an important role in focused ultrasound theranostics. Better understanding of the relationship between the ultrasound parameters and the ADV nucleation could provide an on-demand regulation and enhancement of ADV for improved treatment outcome. In this work, ADV nucleation was performed in a dual-frequency focused ultrasound configuration that consisted of a continuous low-frequency ultrasound and a short high-frequency pulse. The combination was modelled to investigate the effects of the driving frequency and acoustic power on the nucleation rate, efficiency, onset time, and dimensions of the nucleation region. The results showed that the inclusion of short pulsed high-frequency ultrasound significantly increased the nucleation rate with less energy, reduced the nucleation onset time, and changed the length-width ratio of the nucleation region, indicating the dual-frequency ultrasound mode yields an efficient enhancement of the ADV nucleation, compared to a single-frequency ultrasound mode. Furthermore, the acoustic and temperature fields varied independently with the dual-frequency ultrasound parameters. This facilitated the spatial and temporal control over the ADV nucleation, and opens the door to the possibility to realize on-demand regulation of the ADV occurrence in ultrasound theranostics. In addition, the improved energy efficacy that is obtained with the dual-frequency configuration lowered the requirements on hardware system, increasing its flexibility and could facilitate its implementation in practical applications.

A new versatile MR-guided high-intensity focused ultrasound (HIFU) device for the treatment of musculoskeletal tumors

Magnetic Resonance (MR) Imaging-guided High Intensity focused Ultrasound (MRgHIFU) is a non-invasive, non-ionizing thermal ablation therapy that is particularly interesting for the palliative or curative treatment of musculoskeletal tumors. We introduce a new modular MRgHIFU device that allows the ultrasound transducer to be positioned precisely and interactively over the body part to be treated. A flexible, MR-compatible supporting structure allows free positioning of the transducer under MRI/optical fusion imaging guidance. The same structure can be rigidified using pneumatic depression, holding the transducer rigidly in place. Targeting accuracy was first evaluated in vitro. The average targeting error of the complete process was found to be equal to 5.4 ± 2.2 mm in terms of focus position, and 4.7° ± 2° in terms of transducer orientation. First-in-man feasibility is demonstrated on a patient suffering from important, uncontrolled pain from a bone metastasis located in the forearm. The 81 × 47 × 34 mm³ lesion was successfully treated using five successive positions of the transducer, under real-time monitoring by MR Thermometry. Significant pain palliation was observed 3 days after the intervention. The system described and characterized in this study is a particularly interesting modular, low-cost MRgHIFU device for musculoskeletal tumor therapy.