High-intensity Focused Ultrasound Research Articles

Continuous transcranial ultrasound in large vessel stroke: Image guidance for high-intensity focused sonothrombolysis.

Sonothrombolysis is a potential adjunctive therapy for large vessel occlusion (LVO) stroke. Bedside ultrasound image-guided high-intensity focused ultrasound (HIFU) therapy could deliver higher energy therapeutic ultrasound to the thrombus with higher precision than what was previously accomplished in human trials. The aim is to test the feasibility of diagnostic transcranial contrast-enhanced ultrasound (CEUS) to image the occlusion site and continuously maintain the guidance image on-target for a sufficient exposure time for HIFU to be effective during LVO stroke evaluation and treatment. This prospective, single center, observational cohort study included adult patients, presenting within 6 hours of stroke symptom onset, with LVO identified on computed tomography angiography (CTA). A hand-held CEUS imaging study was initiated following CTA and lasted up to 30 minutes. The primary outcome is the proportion of patients where a guidance CEUS image of the occlusion was achieved. A CEUS image of the occluded artery was obtained in 32/35 of the included patients. The median total imaging time was 23 minutes (interquartile range 15-30). Patients undergoing thrombectomy had a lower total imaging time (17 vs. 29.5 minutes, p=.002). When imaging was successful, on-target image was maintained for only 58% (standard deviation 23.8%) of total imaging time. No complications related to CEUS were observed. This feasibility study explored the use of diagnostic transcranial CEUS for continuous imaging of occlusion sites in LVO strokes. Challenges in maintaining target image during HIFU were identified, highlighting the need for technical advances for clinical application.

Pilot study on the impact of HIFU treatment on miRNA profiles in vaginal secretions of uterine fibroids and adenomyosis patients

Background High intensity focused ultrasound (HIFU) ablation treatment for uterine fibroids and adenomyosis has been long developed. The aim of this study is to investigate miRNA profile changes in vaginal secretions after HIFU treatment and their clinical relevance. Methods We prospectively collected vaginal secretions samples from 8 patients (1 with adenomyosis and 7 with fibroids) before and after HIFU treatment. RNA was isolated and miRNA profiles were analyzed using next-generation sequencing (NGS) sequencing. Results Our study showed miRNA profile change in vaginal secretion samples after HIFU treatment for uterine fibroids/adenomyosis, with 33 miRNAs upregulated and 6 downregulated overall. In fibroid cases, 31 miRNAs were upregulated and 7 downregulated, while in adenomyosis case, 41 miRNAs were upregulated and 71 downregulated. Four miRNAs (hsa-miR-7977, hsa-miR-155-5p, hsa-miR-191-5p, hsa-miR-223-3p) showed significant differences after HIFU treatment in fibroid cases, except in case 5 with the lowest treatment sonications (425 sonications) and energy input (170000 J). hsa-miR-7977 consistently showed downregulation after HIFU treatment. hsa-miR-155-5p were downregulated in case 4 with lowest treatment efficiency (2439.64 J/cm3), while they were upregulated in other cases. hsa-miR-191-5p and hsa-miR-223-3p were downregulated in cases 4 and 7, with case 7 influenced by high sonication and energy due to multiple fibroids. Conclusions HIFU treatment altered miRNA profiles in fibroids/adenomyosis patients. Notably, hsa-miR-7977, hsa-miR-155-5p, hsa-miR-191-5p, and hsa-miR-223-3p showed significant changes in fibroid cases, except in low-energy treatments. hsa-miR-7977 consistently decreased post-treatment, while hsa-miR-155-5p decreased in the least efficient cases. Further research is needed for validation.

Real-World Safety of Prostate Cancer Focal Therapy: MAUDE Database Analysis.

Objective: The aim of this study was to assess the real-world safety profile of medical devices used in focal prostate cancer treatment utilizing the Manufacturer and User Facility Device Experience (MAUDE) database. Methods: The MAUDE database was searched for reports on high-intensity focused ultrasound (HIFU), cryoablation, laser ablation, and irreversible electroporation (IRE) devices used in prostate cancer treatment from 1993 to 2023. Adverse events were identified and categorized. Results: We identified 175 reports for HIFU, 1362 for cryoablation, 615 for laser ablation, and 135 for IRE devices, with 28, 284, 126, and 2 respective reports, directly related to prostate cancer treatment. The aggregated data revealed the majority of complications were minor, with 82.5% (n = 363 out of 440 total complications) classified as Clavien-Dindo grade 1 or 2. Common minor complications included erectile dysfunction and urinary retention. Severe complications such as rectal fistulas were noted in HIFU and IRE treatments, along with singular mortality due to pulmonary embolism in cryoablation. Conclusions: Our analyses from MAUDE reveal that devices used in focal therapy for prostate cancer are predominantly associated with minor complications, underscoring their overall real-world safety profile. However, the occurrence of severe adverse events emphasizes the critical importance of rigorous patient selection and meticulous procedural planning. These findings provide valuable insights into the safety profile of focal therapy devices and contribute to the growing body of evidence on their use in prostate cancer treatment.

Comparative study of HIFU partial gland ablation and robot-assisted radical prostatectomy for localized prostate cancer: an evidence-based approach.

This research aims to use a data-driven analytical method to compare the effectiveness of High-Intensity Focused Ultrasound (HIFU) partial gland ablation with Robot-Assisted Radical Prostatectomy (RARP) for treating localized prostate cancer, evaluating variations in treatment results. We performed a systematic review of the literature, covering key databases including the Cochrane Library, PubMed, EMBASE, Web of Science, and Google Scholar, with the latest information updated until August 2024. We utilized Stata 18 for data analysis, computing weighted mean differences (WMDs) for continuous data and odds ratios (ORs) for categorical data, with all results reported alongside 95% confidence intervals (CIs). Additionally, the studies included were evaluated using the Newcastle-Ottawa Scale (NOS). This meta-analysis incorporated data from three paired studies, encompassing a total of 1,503 patients. Patients treated with HIFU experienced a shorter hospital stay (WMD = -2.78, 95%CI -5.14,-0.43; p = 0.02) compared to those who received RARP. Additionally, evaluations at 3 and 12months post-surgery revealed that the HIFU group exhibited better recovery in urinary continence and sexual function than the RARP group. However, there were no notable disparities in complication rates (OR = 1.48, 95%CI 0.92,2.40; p = 0.110) and the requirement for salvage therapy (OR = 2.92, 95%CI 0.60,14.33; p = 0.186) between the two treatment methods. In conclusion, this meta-analysis appears to suggest potential benefits of HIFU partial gland ablation in possibly reducing the length of hospital stays and seems to indicate that it might be associated with improved recovery in terms of urinary incontinence and sexual function, particularly during the early to mid-term postoperative period. Although the differences in complication rates and the requirement for salvage therapy between the two surgical methods were not statistically significant, the findings provided by this analysis are instrumental in guiding clinical decision-making.

The use of focal therapy for the treatment of prostate cancer in Canada: Where are we, how did we get here, and where are we going?

Focal therapy is an emerging treatment for localized prostate cancer. The objectives of this review were to: 1) review how focal therapies are regulated and approved; 2) summarize the scope and quality of the literature regarding safety, efficacy, and side-effects; and 3) outline ongoing clinical trials of focal therapy in Canada. Using the PRISMA framework for scoping reviews, we searched PubMed, Embase, and Cochrane from 2021-2024, complementing Hopstaken et al's search up functional and oncologic outcomes. Additionally, we examined the FDA database for regulatory details and ongoing trials in Canada via ClinicalTrial.gov. FDA approval for prostate tissue ablation was granted to high-intensity focused ultrasound (HIFU) in 2015 via the de novo pathway; other therapies followed the 510(k) route, citing equivalence to predicate devices. Most studies are in early stages, primarily single-arm, prospective cohort designs. Oncologic outcomes like cancer detection and survival rates, alongside functional data, such as adverse events and erectile function, were assessed. Recurrence-free survival at 48 months ranged from 58-92%, pad-free rates were greater than 95%, and rates of new-onset erectile dysfunction were variable, ranging from no change to 50%. Rates of serious adverse events (SAEs) were low, ranging from 0-14%. Three Canadian clinical trials are actively enrolling participants, and five private clinics were found offering private HIFU, irreversible electroporation (IRE), or transurethral ultrasound ablation (TULSA). Focal therapy technologies have gained regulatory approval for prostate tissue ablation, and, aside from provincial support for cryoablation in Alberta, are available to Canadians through private payment or clinical trials. Many studies demonstrate promising cancer control and impressive functional outcomes but are limited by their short followup and lack of comparator group. Clinical trial or registry participation should be prioritized to ensure an evidence-based integration into current prostate cancer treatment approaches.

High-intensity focused ultrasound (HIFU) for the treatment of female urinary incontinence: A retrospective analysis.

This study aims to demonstrate the effectiveness of high-intensity focused ultrasound, a noninvasive treatment, for managing urinary incontinence (UI) in women. This is a single-center, retrospective study involving 28 women. Patients, aged between 32 and 65, were included. Patients with insulin-dependent diabetes, neurological disease, active urinary tract infection, undiagnosed vaginal bleeding, who had incontinence surgery, and receiving estrogen therapy were excluded from the study. Incontinence severity was evaluated with the International Incontinence Consultation Questionnaire Short Form (ICIQ-SF). Patients were evaluated before treatment and 6 months after treatment using the ICIQ-SF and the Pelvic Organ Prolapse/Urinary Incontinence Sexual Function Assessment short form. In the analysis of numerical variables independent or paired t test or linear mixed effects models were used. Least square means were used in post hoc comparisons. Mean age of the patients was 45.50 ± 7.59 years. There were 18 (64%) stress urinary incontinence (SUI) and 10 (36%) mixed urinary incontinence (MUI). Six months after treatment, mean ICIQ-SF and Pelvic Organ Prolapse/Urinary Incontinence Short Form Questionnaire scores showed a significant positive change. After the procedure, UI completely disappeared in 43% of the patients. The rate of severe UI decreased from 39% to 8%, and very severe UI decreased from 8% to 0%. Incontinence severity was significantly different in the MUI and SUI groups before and after the procedure. After the procedure, UI completely disappeared in 67% of the patients in the SUI group, while it remained at a mild level in 33%. The decrease in ICIQ-SF score in the SUI group was significantly higher than that in the MUI group. There were no severe adverse events, in 4 patients there was mild vaginal discharge which resolved in 1 week. This study showed that high-intensity focused ultrasound treatment, can be effective and safe even in a single session. Selection and recall biases are potential biases in retrospective studies. Lacking a control group is another limitation. Although advances in technology are very important for medical treatments, their effectiveness and safety need to be proven. Future research in this area with a larger sample size and a prospective design will offer further evidence supporting effectiveness of this treatment model.

Impact of Surface Chemistry and Particle Size on Inertial Cavitation Driven Transport of Silica Nanoparticles and Microparticles

AbstractThis study investigated the high‐intensity focused ultrasound (HIFU)‐mediated propulsion of mesoporous silica nanoparticles (MSNs) and microspheres (MSMs). Nanoparticles are heavily sought as vehicles for drug delivery, but their transport through tissue is often restricted. Here, MSNs and MSMs are hydrophobically modified and coated with phospholipids to facilitate inertial cavitation to promote propulsion under HIFU. Modified nanoparticles show significantly enhanced cavitation and propulsion, achieving a maximum displacement of 250 µm (≈2500 body length) and speed of ≈1600 µm s−1 (16 000 body length s−1), compared to unmodified nanoparticles (2 µm, 20 body length, 60 µm s−1, 600 body length). In contrast, microparticles demonstrate comparable cavitation responses. Modified microparticles reached a maximum speed of 4000 µm s−1 (800 body length s−1) and displacement of 230 µm (46 body length), and unmodified microparticles achieved 2000 µm s−1 (400 body length s−1) and 75 µm (15 body length). In all HIFU‐responsive samples, displacement and speed decreased with successive pulses, implying that particles fatigue with continued pulsing. Analyses of particle trajectories and rotational diffusion times suggest that cavitation occurs uniformly on particle surfaces rather than at specific sites. These principles are important for the design of future drug‐delivery vehicles capable of ultrasound‐triggered motion.

Ultrasound Molecular Imaging Enhances High-Intensity Focused Ultrasound Ablation on Liver Cancer With B7-H3-Targeted Microbubbles.

High-intensity focused ultrasound (HIFU) is a promising minimally invasive treatment for liver cancer; however, its efficacy is often limited by the attenuation of ultrasonic energy. This study investigates the effectiveness of B7-H3-targeted microbubbles (T-MBs) in enhancing HIFU ablation of liver cancer and explores their potential for clinical translation. T-MBs and isotype control microbubbles (I-MBs) were synthesized through the conjugation of biotinylated anti-B7-H3 antibody and isotype control antibody to the microbubble surface, respectively. Contrast-enhanced ultrasound imaging was performed to compare the accumulation of T-MBs and I-MBs in liver cancer at various time points. The efficacy of T-MBs in enhancing HIFU treatment was evaluated by measuring the immediate tumor ablation rate and long-term tumor growth suppression. Additionally, the induced antitumor immune response was assessed through cytokine quantification in serum and tumor tissue, along with immunofluorescence staining conducted on days 1, 3, and 7 post-treatment. T-MBs demonstrated superior liver cancer-specific accumulation, characterized by higher concentrations and prolonged retention compared to I-MBs. The combination of T-MBs with HIFU resulted in significantly enhanced tumor ablation rates and superior tumor growth suppression. Post-treatment analysis revealed a gradual uptick in cytokine levels within the tumor microenvironment, along with progressive infiltration of antitumor immune cells. T-MBs effectively enhance the therapeutic efficacy of HIFU for liver cancer treatment while simultaneously promoting an antitumor immune response. These findings provide a strong experimental foundation for the clinical translation of ultrasound molecular imaging combined with HIFU as a novel approach for tumor therapy.

Three-dimensional Analysis of Lifting Effects after High-intensity Focused Ultrasound (Ultraformer-MPT) across Seven Facial Aesthetic Units Considering SonoAnatomy.

This investigation delves deep into the lifting degree for each area of noninvasive facial rejuvenation through high-intensity focused ultrasound (HIFU). The study meticulously examines the lifting effects of HIFU treatment across seven distinct facial aesthetic-units, using advanced three-dimensional scanner analysis. The study examined a cohort of 50 patients treated with HIFU. Pre- and immediate posttreatment evaluations were conducted using three-dimensional scanner analysis, allowing for precise quantification of lifting effects across seven aesthetic units. Treatment protocols were tailored to leverage five cartridges with micropulsed mode options, optimizing outcomes based on sonographic anatomy. The forehead was lifted by 1.24 mm; crow's feet, 2.25; malar region, 2.46; posterior cheek, 3.40; jowl, 2.90; mandible, 3.09; and neck, 3.53. The forehead showed a lift of 1.24 mm, attributed to the thin tissue requiring a cautious approach to avoid discomfort. A lift of 2.25 mm in the crow's feet area demonstrated the efficacy of HIFU in addressing fine lines and wrinkles. Significant lift of 2.47 mm in the malar region highlights HIFU's effectiveness in addressing mid-face laxity and restoring volume to the cheeks. The most substantial lift of 3.38 mm in the posterior cheek underscores targeted energy application for enhanced lifting and contouring. Notable lifting effect of 2.90 mm in the jowl area benefits sagging along the jawline, refining facial contour. Lift of 3.10 mm in the mandible shows improvement of lower facial laxity, defining the jawline. The highest lift of 3.55 mm in the neck region addresses laxity and sagging for a defined neck profile.

A comprehensive numerical procedure for high-intensity focused ultrasound ablation of breast tumour on an anatomically realistic breast phantom.

High-Intensity Focused Ultrasound (HIFU) as a promising and impactful modality for breast tumor ablation, entails the precise focalization of high-intensity ultrasonic waves onto the tumor site, culminating in the generation of extreme heat, thus ablation of malignant tissues. In this paper, a comprehensive three-dimensional (3D) Finite Element Method (FEM)-based numerical procedure is introduced, which provides exceptional capacity for simulating the intricate multiphysics phenomena associated with HIFU. Furthermore, the application of numerical procedures to an anatomically realistic breast phantom (ARBP) has not been explored before. The integrity of the present numerical procedure has been established through rigorous validation, incorporating comparative assessments with previous two-dimensional (2D) simulations and empirical data. For ARBP ablation, the administration of a 0.1 MPa pressure input pulse at a frequency of 1.5 MHz, sustained at the focal point for 10 seconds, manifests an ensuing temperature elevation to 80°C. It is noteworthy that, in contrast, the prior 2D simulation using a 2D phantom geometry reached just 72°C temperature under the identical treatment regimen, underscoring the insufficiency of 2D models, ascribed to their inherent limitations in spatially representing acoustic energy, which compromises their overall effectiveness. To underscore the versatility of this numerical platform, a simulation of a more clinically relevant HIFU therapy procedure has been conducted. This scenario involves the repositioning of the ultrasound focal point to three separate lesions, each spaced at 3 mm intervals, with ultrasound exposure durations of 6 seconds each and a 5-second interval for movement between focal points. This approach resulted in a more uniform high-temperature distribution at different areas of the tumour, leading to the ablation of almost all parts of the tumour, including its verges. In the end, the effects of different abnormal tissue shapes are investigated briefly as well. For solid mass tumors, 67.67% was successfully ablated with one lesion, while rim-enhancing tumors showed only 34.48% ablation and non-mass enhancement tumors exhibited 20.32% ablation, underscoring the need for multiple lesions and tailored treatment plans for more complex cases.

Advances in Adenomyosis Treatment: High-Intensity Focused Ultrasound, Percutaneous Microwave Therapy, and Radiofrequency Ablation.

Background/Objectives: Adenomyosis is a debilitating gynecologic condition that affects both multiparous older women and nulliparous younger women, inducing a variety of symptoms such as dysmenorrhea, menorrhagia, and infertility. Thermal ablation techniques are new procedures that have been proposed for the treatment of adenomyosis. They include high-intensity focused ultrasound (HIFU), percutaneous microwave ablation (PMWA), and radiofrequency ablation (RFA). Because thermal ablation techniques are minimally invasive or noninvasive, fertility is not impaired while symptoms improve. In addition, hospital stays and financial costs are generally reduced, increasing the interest in these alternative management options. Methods: In this narrative review, we conducted a thorough literature search of PubMed/Medline from the database inception to September 2022. In our search, we focused on noninvasive treatment methods such as HIFU ablation, RFA ablation, and PMWA as well as adenomyosis-specific terms and noninvasive techniques (ultrasonography, ultrasound, or magnetic resonance imaging). The queries were a combination of MeSH terms and keywords. The search was limited to the English language. Abstracts were screened according to their content, and relevant articles were selected. Results: Overall, the results showed that the above-mentioned ablation techniques are effective and safe in providing adenomyosis treatment. Lesion size and uterus volume are reduced, leading to considerable symptom alleviation with all three methods. Positive results concerning safety and fertility preservation have been described as well. Conclusions: Nonetheless, more research is required in this field to compare the efficacy and safety of different ablation techniques with traditional therapies. Such research will help improve these procedures and their associated decision-making processes.

Effect of “T2-rim sign” related parameters on high-intensity focused ultrasound ablation of uterine fibroids

PurposeTo investigate the effect of “high-signal-intensity peripheral rim on T2-weighted MR images (T2-rim sign)” related parameters on non-perfused volume ratio (NPVR) after high-intensity focused ultrasound (HIFU) ablation of uterine fibroids. MethodsData from 616 patients with uterine fibroids treated with HIFU were retrospectively analyzed. Univariate and multivariate logistic regression was used to analyze the factors influencing the ablation effect. The effect of T2-rim sign on ablation parameters and results was also analyzed. Spearman correlation analysis was used to compare the correlation between coverage ratio, average thickness of T2-rim sign and NPVR in 207 cases of fibroids with T2-rim sign. ResultsThe presence of T2-rim sign was an independent risk factor affecting the ablation effect. The coverage ratio of T2-rim sign was negatively correlated with treatment efficiency (r = -0.174, p = 0.012) and NPVR (r = -0.186, p = 0.007), and positively correlated with energy efficiency factor (EEF) (r = 0.156, p = 0.024). The average thickness of T2-rim sign was positively correlated with treatment intensity (r = 0.203, p = 0.003) and negatively correlated with NPVR (r = -0.363, p < 0.001). There was a negative correlation between the average thickness of the T2-rim sign and NPVR in isointense fibroids (r = -0.484, p < 0.001). ConclusionThe presence of T2-rim sign increases the difficulty of ablation and reduces the ablation effect. In clinical practice, the presence and related parameters of T2-rim sign should be fully considered when screening for HIFU indications and formulating treatment plans.

Trends in focal therapy for localized prostate cancer: a bibliometric analysis from 2014 to 2023

Focal therapy, a minimally invasive strategy for localized prostate cancer, has been widely employed in the targeted treatment of localized prostate cancer in recent years. We analyzed 1312 relevant papers from the last decade using Web of Science Core Collection data. Our analysis covered countries, institutions, journals, authors, keywords, and references to offer a multifaceted perspective on the development of this field. The U.S. led in publications, contributing over half of the top 10 institutions. Emberton, M from University College London was the most published and cited author. “EUROPEAN UROLOGY” was the top journal by impact factor in 2022. Analysis of references and keywords suggests the prevalence of brachytherapy-related research, while high-intensity focused ultrasound (HIFU), cryotherapy, and irreversible electroporation (IRE) are emerging as new research focuses. Consequently, more high-quality evidence is necessary to evaluate the long-term effectiveness and safety of these novel therapeutic methods.

Characterizing Temperature-Dependent Acoustic and Thermal Tissue Properties for High-Intensity Focused Ultrasound Computational Modeling

High-intensity focused ultrasound (HIFU) thermal therapies utilize concentrated sound waves to ablate diseased tissue at precise locations within the body. Computational simulations of HIFU can assist clinicians by predicting the death of target tissues, identifying sensitive healthy tissues that risk thermal damage, and optimizing acoustic power delivery to minimize treatment times and maximize treatment efficacy. Accurate simulations require accurate inputs, and many computational solvers neglect property changes induced by tissue heating during treatment. Additionally, temperature-dependent tissue property data in the literature are relatively scarce. This study presents methodology for characterizing temperature-dependent acoustic and thermal properties in ex vivo porcine muscle tissue. From 20 – 50 °C, speed of sound is found to increase from approximately 1580 – 1620 m/s. The acoustic attenuation coefficient increases for 20 – 50 °C from 0.09 – 0.24 Np/cm at 0.5 MHz and 0.16 – 0.37 Np/cm at 1.6 MHz. Thermal conductivity and thermal diffusivity increase from 0.52 – 0.55 W/m °C and 0.147 – 0.158 mm2/s, respectively, over 20 – 60 °C. Specific heat capacity increases from approximately 3500 – 3800 J/kg °C, over 20 – 80 °C. Each property is consistent with data found in the literature, extends the literature to a larger temperature range, and, for acoustic properties, extends to unique frequencies. Temperature-dependent predictive models are also developed for each of the five properties. This study’s property measurement methodologies can be used to characterize other biological tissues, and the predictive models developed herein will facilitate future efforts in temperature-dependent modeling and uncertainty quantification of HIFU thermal therapies.

The Role of Whole-Gland and Focal Cryotherapy in Recurrent Prostate Cancer.

Prostate cancer is the most common non-cutaneous malignancy in men, with the majority of newly diagnosed patients eligible for active surveillance. Despite definitive treatment, a considerable percentage of men will experience biochemical recurrence and even regional and distant metastatic recurrence after radiation therapy or radical prostatectomy. Salvage prostatectomy, while oncologically effective, poses significant morbidity with poor functional outcomes. Salvage cryotherapy has emerged as a promising alternative for localized recurrence, demonstrating safety and efficacy. This review examines the oncologic and functional outcomes of whole-gland and focal salvage cryotherapy, including disease-free survival, cancer-specific survival, and overall survival. The crucial role of multiparametric prostate MRI and evolving role of next-generation PSMA-targeted PET imaging are also examined. The comparison of outcomes of cryotherapy to other salvage ablation modalities, such as high-intensity focused ultrasound (HIFU), is also explored.

Evaluation Effectiveness of Pre-Treatment Combined with Ultrasound-Guided Suction Curettage in Cesarean Scar Pregnancy: A Retrospective Cohort Study

Background: The objective of this study is to assess the effectiveness of ultrasound-guided suction curettage (UGSC) in conjunction with or without high-intensity focused ultrasound (HIFU) or uterine artery embolization (UAE) for the treatment of three distinct types of cesarean scar pregnancy (CSP). Methods: This was a retrospective study that included subjects diagnosed with CSP in a single tertiary referral centre from January 2015 to December 2020. UGSC associated with/without pretreatment was offered to CSP patients according to the location of pregnancy sac, the depth of implantation and the surrounding blood flowing. The data about baseline characteristics and outcome parameters were analyzed across the three groups. Results: The present study included 434 patients diagnosed with CSP. The majority were cured without severe complication except one case accepted blood transfusion. The baseline data from the three groups did not differ statistically. The UGSC group had the same successful rate of treating type I CSP with a shorter hospital stay (χ2 = 51.771, p = 0.000) compared to the HIFU or UAE groups. Type II CSP presented marked less blood loss (Z = –2.464, p = 0.014) and higher decline ration of beta-human chorionic gonadotropin (β-HCG) (Z = –4.728, p = 0.000) in HIFU group. Treatment success was high in patients with type III CSP in both the HIFU and UAE groups, but the rate of β-HCG decline was higher in the HIFU group (Z = –2.255, p = 0.024). Conclusions: This study suggests that UGSC is an effective and safe option for patients with low-risk CSP. HIFU or UAE combined with UGSC has higher efficacy in high-risk CSP. And HIFU may be superior in reducing bleeding and increasing the rate of β-HCG decline.

Protocol for high‐intensity focused ultrasound (HIFU) treatment of cutaneous neurofibromas

Protocol for high‐intensity focused ultrasound (HIFU) treatment of cutaneous neurofibromas

High-Intensity focused ultrasound linear array and system for dermatology treatment

Dermatological lesions are typically located just a few millimeters below the surface of the skin, which constrains the efficacy of optical-based therapeutic methods such as photothermal and photodynamic therapy due to limited therapeutic depth caused by optical scattering. As an alternative, high-intensity focused ultrasound (HIFU) has been explored for its potential to treat a variety of dermatological conditions because it offers greater flexibility in terms of treatment depth. Since dermatological lesions have a small thickness ranging from 1.5 to 2.0 mm, high-frequency ultrasound (3–10 MHz or higher) is preferred as the focal area is proportional to the operating frequency. However, due to the difficulty in fabricating HIFU array transducers at this frequency range, the majority of HIFU treatments for dermatology rely on single element transducers. Despite the advantages of HIFU, single-element-based HIFU systems are limited in prevalent use for dermatology treatment due to their fixed focal length and mechanical movement for treatment, which can be time-consuming and unsuitable for treating multiple lesions. To address this, we present a newly developed HIFU linear array and 128-channel driving electronics specifically designed for dermatology treatment. This array consists of 128 elements, has a center frequency of 3.7 MHz, an elevation focal length of 28 mm, and an F-number of 1.27 in the elevation direction. The array has a footprint of 71.6 mm by 22 mm. Experiments using a tissue-mimicking phantom have demonstrated that the HIFU linear array and system are capable of transmitting sufficient ultrasound energy to create coagulation inside the phantom.

Optimizing high-intensity focused ultrasound-induced immunogenic cell-death using passive cavitation mapping as a monitoring tool

Over the past decade, ultrasound (US) has gathered significant attention and research focus in the realm of medical treatments, particularly within the domain of anti-cancer therapies. This growing interest can be attributed to its non-invasive nature, precision in delivery, availability, and safety. While the conventional objective of US-based treatments to treat breast, prostate, and liver cancer is the ablation of target tissues, the introduction of the concept of immunogenic cell death (ICD) has made clear that inducing cell death can take different non-binary pathways through the activation of the patient's anti-tumor immunity. Here, we investigate high-intensity focused ultrasound (HIFU) to induce ICD by unraveling the underlying physical phenomena and resulting biological effects associated with HIFU therapy using an automated and fully controlled experimental setup. Our in-vitro approach enables the treatment of adherent cancer cells (B16F10 and CT26), analysis for ICD hallmarks and allows to monitor and characterize in real time the US-induced cavitation activity through passive cavitation detection (PCD). We demonstrate HIFU-induced cell death, CRT exposure, HMGB1 secretion and antigen release. This approach holds great promise in advancing our understanding of the therapeutic potential of HIFU for anti-cancer strategies.

Reconfigurable ultrasound focusing effect through acoustic barriers

The low transmission efficiency of ultrasonic waves in waveguides of a high acoustic impedance (referred to as dense materials), due to the impedance mismatch between the background media and the dense materials, poses a significant obstacle to practical applications of high-intensity focused ultrasound (HIFU) such as ultrasound therapy or medical imaging. To address this challenge, we present an inverse optimization scheme for fabrication of novel acoustic meta-lenses, enabling strengthened penetration and enhanced focusing of ultrasonic waves when the waves traverse barriers. Both simulation and experiment validate the effectiveness of the developed meta-lenses which are annexed to hemispherical plates, and demonstrate an enhanced transmission of the sound power by an order of magnitude compared to a scenario without the use of the meta-lens. The focal distance is reconfigurable by adjusting the geometric parameters of the meta-lenses. The proposed design philosophy is not restricted by the complexity of the target structures, and it allows the ultrasonic waves to pass through acoustic barriers with a non-uniform thickness yet maintaining efficient wave focusing. This study holds appealing applications in HIFU-enabled ultrasound imaging and therapy.