Advancing Boiling Histotripsy Dose in Ex Vivo And In Vivo Renal Tissues Via Quantitative Histological Analysis and Shear Wave Elastography.

OBJECTIVE: In the context of developing boiling histotripsy (BH) as a potential clinical approach for non-invasive mechanical ablation of kidney tumors, the concept of BH dose (BHD) was quantitatively investigated in porcine and canine kidney models in vivo and ex vivo. METHODS: Volumetric lesions were produced in renal tissue using a 1.5-MHz 256-element HIFU-array with various pulsing protocols: pulse duration tp = 1-10 ms, number of pulses per point ppp = 1-15. Two BHD metrics were evaluated: BHD1 = ppp, BHD2 = tp × ppp. Quantitative assessment of lesion completeness was performed by their histological analysis and assignment of damage score to different renal compartments (i.e., cortex, medulla, and sinus). Shear wave elastography (SWE) was used to measure the Young's modulus of renal compartments in vivo vs ex vivo, and before vs after BH treatments. RESULTS: In vivo tissue required lower BH doses to achieve identical degree of fractionation as compared to ex vivo. Renal cortex (homogeneous, low in collagen) was equal or higher in stiffness than medulla (anisotropic, collagenous), 5.8-12.2 kPa vs 4.7-9.6 kPa, but required lower BH doses to be fully fractionated. Renal sinus (fatty, irregular, with abundant collagenous structures) was significantly softer ex vivo vs in vivo, 4.9-5.1 kPa vs 9.7-15.2 kPa, but was barely damaged in either case with any tested BH protocols. BHD1 was shown to be relevant for planning the treatment of renal cortex (sufficient BHD1 = 5 pulses in vivo and 10 pulses ex vivo), while none of the tested doses resulted in complete fractionation of medulla or sinus. Post-treatment SWE imaging revealed reduction of tissue stiffness ex vivo by 27-58%, increasing with the applied dose, and complete absence of shear waves within in vivo lesions, both indicative of tissue liquefaction. CONCLUSION: The results imply that tissue resistance to mechanical fractionation, and hence required BH dose, are not solely determined by tissue stiffness but also depend on its composition and structural arrangement, as well as presence of perfusion. The SWE-derived reduction of tissue stiffness with increasing BH doses correlated with tissue damage score, indicating potential of SWE for post-treatment confirmation of BH lesion completeness.

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.

Focused ultrasound for the treatment of facet joint pain: a systematic review.

OBJECTIVE: Chronic low-back pain (LBP) is a leading cause of disability worldwide, and traditional pharmacotherapy fails to provide relief for many individuals with this condition. An estimated 15% of chronic LBP cases can be attributed to the facet joint. High-intensity focused ultrasound (HIFU) is a recent technology that enables noninvasive thermal ablation of tissue and has shown efficacy in treating tumors, neuropathic pain, and painful bone metastases. In this systematic review, the authors summarize the literature on lumbar facet joint-mediated pain treated with HIFU and report the effectiveness of HIFU on pain outcomes. METHODS: All full-text English-language articles describing the use of focused ultrasound for facet joint pain were screened using the PubMed/MEDLINE, Embase, Cochrane Library, Scopus, and Web of Science databases. Clinical studies were assessed for bias using the methodological index for nonrandomized studies. RESULTS: Eleven studies (6 preclinical and 5 clinical) reporting on 50 patients were included. Eight of these studies (73%) used MR-guided focused ultrasound ablation and 3 used fluoroscopy. The medial branch nerve and posterior facet joint capsule were the most common targets for focused ablation. Although the energy used ranged from 300 to 2000 J, clinical studies predominantly operated in the range of 1000 to 1500 J. Pain reduction was seen in all clinical studies, with multiple-point reductions from average baseline pain scores in 6-12 months. No study reported any adverse events or complications. CONCLUSIONS: HIFU can be effective in treating chronic low-back pain arising from the facet joint. Further clinical studies should explore the long-term effects of HIFU and monitor changes in pain reduction over time.

High-intensity focused ultrasound ablation combined with hysteroscopy for the treatment of uterine arteriovenous fistula associated with retained products of conception: a prospective cohort study.

OBJECTIVE: To evaluate the efficacy of combining high-intensity focused ultrasound (HIFU) ablation with hysteroscopic removal of retained products of conception in the presence of a uterine arteriovenous fistula (UAVF). DESIGN: Prospective cohort study SETTING: Tertiary hospital. PARTICIPANTS: 17 patients with UAVF and retained products of conception. INTERVENTIONS: HIFU ablation combined with hysteroscopic removal of retained products of conception RESULTS: All patients presented with irregular vaginal bleeding following pregnancy termination and not responsive to medical treatment. Patients were confirmed to have a UAVF along with concurrent intrauterine residue using three-dimensional color Doppler ultrasonography, uterine angiography, or pelvic-enhanced magnetic resonance imaging; and demonstrated a poor response to medical treatment. Under real-time ultrasound guidance, HIFU was used to ablate the arteriovenous malformation region. Patients underwent hysteroscopic removal of retained products of conception; the removed tissue was subjected to pathological examination. All patients underwent monthly uterine color Doppler ultrasound examinations and menstrual status follow-up within 3 months postoperatively and showed normal menstrual recovery without signs of arteriovenous malformations on ultrasonography. Pathological examination of the tissues removed during hysteroscopic clearance revealed characteristics consistent with pregnancy, with abnormal blood vessels in some tissues. All patients experienced normal menstrual recovery postoperatively, without intrauterine adhesions. CONCLUSION: Combining HIFU ablation with postoperative hysteroscopic surgery effectively treats pregnancy related UAVF with minimal complications, preserves fertility; it offers an additional treatment option for patients wanting future fertility.

Clinical efficacy and safety of high-intensity focused ultrasound combined with ultrasound-guided suction curettage at different time intervals for Cesarean scar pregnancy: a retrospective study.

OBJECTIVE: This study aims to assess the clinical efficacy and safety of combining high-intensity focused ultrasound (HIFU) with ultrasound-guided suction curettage for the treatment of cesarean scar pregnancy (CSP) at different time intervals. METHODS: A total of 115 CSP patients were enrolled and divided into two groups based on the time between HIFU ablation and suction curettage. Group A (n = 50) underwent suction curettage 24-48 h after HIFU ablation, while Group B (n = 65) had suction curettage within 6 h of HIFU ablation. The study compared and analyzed the clinical characteristics, treatment success rates, and intraoperative hemorrhage during ultrasound-guided suction curettage. RESULTS: The demographic characteristics of the two groups were similar, with no statistically significant differences observed in HIFU parameters, treatment success rates, blood loss, the use of Foley catheter balloons, or hospital expenses (p > 0.05). Importantly, suction curettage performed within 6 h after HIFU ablation resulted in shorter hospitalization times compared to suction curettage performed 24-48 h after the ablation (p < 0.05). CONCLUSIONS: Suction curettage within 6 h after HIFU ablation is an effective, safe, and cost-efficient treatment for patients diagnosed with CSP.

Future Directions of MR-guided Focused Ultrasound.

MR-guided focused ultrasound (MRgFUS) allows for the incisionless treatment of intracranial lesions in an outpatient setting. While this is currently approved for the surgical treatment of essential tremor and Parkinson's disease, advancements in imaging and ultrasound technology are allowing for the expansion of treatment indications to other intracranial diseases. In addition, these advancements are also making MRgFUS treatments easier, safer, and more efficacious.

Noninvasive high-intensity focused ultrasound for skin brightening efficacy using a topical agent containing glutathione and hyaluronic acid.

BACKGROUND: High-intensity focused ultrasound (HIFU) is well-documented for skin rejuvenation, lifting, and tightening. However, its synergistic effects with topical agents, enhanced by HIFU-induced vibration and heat, remain underexplored. OBJECTIVE: To evaluate clinical and photographic outcomes of HIFU combined with a topical agent versus the topical agent alone. METHOD: This non-randomized controlled trial involved 20 female volunteers (ages 30-55) divided into two groups. Group A (n = 10) received two HIFU sessions combined with a topical agent containing glutathione and hyaluronic acid. Group B (n = 10) received the topical agent alone. Outcomes were assessed using digital photography, patient satisfaction surveys, and the A-One Smart™ system for fine wrinkles, hyperpigmentation, and hydration. Skin brightening was evaluated with the Global Esthetic Improvement Scale (GAIS). RESULTS: Group A showed significant reductions in fine wrinkles (6.25 ± 2.00 mm to 3.10 ± 1.62 mm), improved hyperpigmentation (3.50 ± 0.80 to 2.10 ± 1.05), and increased hydration (28 ± 10 to 55 ± 11) (all p < 0.05). Over two-thirds of Group A reported significant improvements, with no complications. Group B showed minimal, non-significant changes (p > 0.05), with only 30% reporting noticeable improvements. CONCLUSION: Combining HIFU with a topical agent significantly enhances skin quality and brightness without adverse effects.

Prostate cancer focal therapy: surgeon experience influences oncological results.

INTRODUCTION: Characterization of the index lesion of prostate cancer (PCa) has facilitated the development of focal therapy to reduce complications caused by radical treatments. In the present study, we sought to identify factors associated with the oncological results of focal therapy for PCa. METHODS: Between April 2017 and February 2020, 123 PCa patients received focal therapy performed with high-intensity focused ultrasound (HIFU). The patients presented unilateral localized disease, PSA < 20 ng/dl, clinical stage T1-T2, ISUP grade 1-3, and more than 10 years of life expectancy. Five certified surgeons with different levels of experience performed the procedures and were divided into groups #1 and #2 (>30 HIFUs performed) and #3 (10-15 HIFUs performed each). All patients were prospectively followed and underwent surveillance biopsy 1 year post-treatment. The primary endpoint was radical treatment, and secondary endpoints included focal therapy failure and in-field recurrence. Univariate and multivariate logistic regression were used to detect associations between clinical and procedure variables and the endpoints. RESULTS: The median follow-up was 54.3 months, with a mean age of 64.4 years. The mean PSA was 6.6 ng/dl; 59.3% of patients had intermediate-risk disease, and the remaining had low-risk. During follow-up, 29 (23.6%) patients required radical treatment (external beam radiation therapy), 37 (30.1%) experienced treatment failure, and 26 (21.1%) had an in-field recurrence with an ISUP grade of ≥2. Radical treatment in the follow-up was associated with patients treated by surgeons in group #3 and with elevated post-HIFU PSA concentrations. Baseline PSA concentrations, group #3 surgeons, and post-HIFU PSA concentrations were associated with treatment failure. In-field positive biopsies were associated with baseline and post-HIFU PSA concentrations. Furthermore, patients treated by surgeons in group #3 were independently associated with radical treatment and focal therapy failure. CONCLUSION: Focal therapy with HIFU has acceptable oncological outcomes in the medium term, and the surgeon's experience and technique are independently associated with the need for subsequent radical treatment and focal therapy failure.

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.

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.

Sonographic features of uterine fibroids that predict the ablation rate and efficacy of high-intensity focused ultrasound.

Objective: This study aimed to identify the sonographic indicators that predict the ablation rate and efficiency of uterine fibroids during high-intensity focused ultrasound (HIFU) treatment. Methods: In this retrospective study, we analyzed the clinical data of patients with uterine fibroids who underwent HIFU treatment at Fujian Provincial Hospital between April 2019 and April 2022. Routine abdominal ultrasound examinations were performed to observe potential indicators before the HIFU treatment. After the treatment, enhanced magnetic resonance imaging (MRI) examination was performed within 2 weeks. The fibroid and non-perfused volumes (NPV) were determined, and the ablation rate and energy efficiency factor (EEF) were calculated. Results: A total of 75 patients (124 uterine fibroids) were included in this study. Uterine fibroids with a larger volume, high echogenicity, elliptical/diffuse leaf shape, and a posterior attenuation band had a higher HIFU ablation rate (p<0.05). Uterine fibroids with a larger volume and high echogenicity and without necrotic areas had a lower EEF (p<0.05). Multiple comparisons between fibroid types revealed statistically significant differences in EEF between subserosal and submucosal fibroids (p < 0.05) and between subserosal and mixed-type fibroids (p < 0.05). However, no statistically significant difference was observed between mixed-type and submucosal fibroids. The HIFU ablation rate and EEF showed no significant differences based on location within the wall and blood flow within the fibroids. Conclusion: Sonographic features of uterine fibroids can predict the rate and efficiency of HIFU ablation, providing useful guidance in selecting appropriate treatment for patients.

A costing and health-related quality of life study of high intensity focused ultrasound in primary treatment of localized low or intermediate risk prostate cancer in Ontario.

INTRODUCTION: Prostate cancer is the third leading cause of death from cancer among Canadian men. High intensity focused ultrasound (HIFU) is a novel approach for primary treatment of localized prostate cancer. Little is known, however, about its costs. We aimed to collect the direct costs and health-related quality of life (HRQoL) data of HIFU in primary treatment of localized low and intermediate risk prostate cancer in Ontario. MATERIALS AND METHODS: We collected direct costs and HRQoL data of 20 patients with localized low or intermediate risk prostate cancer who received whole-gland HIFU at a privately owned clinic in Ontario. We compared the direct costs of HIFU, open radical prostatectomy (ORP), robot assisted radical prostatectomy (RARP), and external beam radiation therapy (RT) in primary treatment of localized low and intermediate risk prostate cancer. RESULTS: The average direct costs of HIFU, ORP, RARP, and RT per case in 2023 are $14,886.78, $14,192.26, $21,794.55, and $17,377.51, respectively. The median and interquartile range (IQR) of the study participants' age and HRQoL data prior to the HIFU procedure were 64.5 (11.25) years, 94.5 (8.65), 38.5 (4), 6.0 (4.46), and 22.5 (8.32), respectively. CONCLUSION: Our healthcare payer's perspective costing study revealed median direct costs per case of HIFU and favorable HRQoL outcomes compared to other treatment options for primary treatment of localized low and intermediate risk prostate cancer in Ontario. A health economic model is warranted to analyze the cost-effectiveness of HIFU compared to other treatment options in primary treatment of localized low and intermediate risk prostate cancer.

Experimental Evaluation of an Ultrasound-Guided High-Intensity-Focused Ultrasound Probe for Sonication of Artery.

OBJECTIVES: This study aimed to develop an ultrasound-guided high-intensity-focused ultrasound (USgHIFU) probe for arterial sonication and to evaluate vascular contraction. METHODS: The USgHIFU probe comprised two confocal spherical transducers for sonication and a US color Doppler flow imaging probe for guidance. A vessel-mimicking phantom was sonicated in two directions. In the vascular radial direction, an isolated rabbit aorta embedded in ex vivo pork liver was sonicated at different acoustic powers (245 and 519 W), flow rates (25, 30, and 50 mL/minute), and sonication energies (519, 980, and 1038 J). Changes in the postsonication vessels were evaluated using US imaging, microscopic observation, and histopathological analysis. RESULTS: Beam focusing along the vascular radial direction caused significant deformation of both tube walls (n = 4), whereas focusing along the axial direction only affected the contraction of the anterior wall (n = 4). The contraction index (Dc) of the vessel sonicated at 245 W and 980 J was 56.2 ± 9.7% (n = 12) with 25 mL/minute. The Dc of the vessel sonicated at 519 W and 1038 J was 56.5 ± 7.8% (n = 17). The Dc of the vessel sonicated at 519 J total energy was 18.3 ± 5.1% (n = 12). CONCLUSION: The developed USgHIFU probe induced greater vascular contractions by covering a larger area of the vessel wall in the radial direction. Sonication energy affects vascular contraction through temperature elevation of the vessel wall. When the acoustic power was high, an increase in acoustic power, even with comparable sonication energy, did not result in greater vessel contraction.

Evaluation of the therapeutic efficacy of high-intensity focused ultrasound ablation combined with different drugs in the treatment of adenomyosis.

OBJECTIVES: To observe the therapeutic efficacy of high-intensity focused ultrasound (HIFU) combined with different pharmacological treatments for adenomyosis. MATERIALS AND METHODS: A total of 126 patients with adenomyosis who underwent HIFU combined with pharmacological treatment were retrospectively reviewed. Patients were treated with either dienogest (DNG) (Group A, N = 38) or GnRH-a (Group B, N = 88) for three months after HIFU, and received levonorgestrel-releasing intrauterine systems (LNG-IUS) at the end of the third month. Visual Analog Scale (VAS) and Pictorial Blood Loss Assessment Chart (PBAC) scores were used for evaluating symptom improvement. RESULTS: After propensity score matching (1:2), 38 patients were included in Group A and 76 in Group B. All patients showed significant improvement in VAS and PBAC scores after HIFU, but the PBAC score of Group A was significantly higher than that of patients in Group B at 18 months [11.50 (1.00, 29.50) vs. 0.00 (0.00, 16.50), p < 0.01] and 24 months [4.00 (0.25, 27.75) vs. 0.00 (0.00, 12.75), p = 0.04] after HIFU. Furthermore, patients in Group B had a greater uterine volume reduction at 24 months after HIFU than that of patients in Group A [51.00 (27.00, 62.00) vs. 30.00 (17.00, 42.75, p = 0.02)]. However, the adverse effects in Group A were lower than those in Group B [7 (15.79) vs. 35 (46.05), p < 0.01]. No significant difference was observed in the recurrence rate between the two groups. CONCLUSIONS: HIFU combined with DNG and LNG-IUS is a safe and effective treatment for patients with adenomyosis.

An Updated Review of Thermal Ablation Technology for Uterine Fibroids and Adenomyosis: Focusing on Protecting Fertility.

There is a growing trend towards minimally invasive or noninvasive alternatives for gynecological disorders due to their rapid alleviation of symptom, expedited recovery, and minimal risks of postoperative complications. Thermal ablation technology has been commonly advocated as a minimally invasive therapeutic methods in recent years, including microwave ablation, radiofrequency ablation, and high-intensity focused ultrasound. The increasing application scenarios require updated and systematic research, and more evidence to promote their appropriate use. The objective of this review is to summarize the latest views of ablation from a prospective of fertility protection, endeavor to clarify the clinical value of thermal ablation technology in protecting fertility by assessing parameters such as ablation rates, alleviation of disease symptoms, re-intervention rates and post-treatment pregnancy rates. We review the clinical studies of ablation for uterine fibroids and adenomyosis treatment in the past 10 years, summarize the limitation and the prospects of its development in the treatment process, so as to provide clinicians with advice on the best practice. In the management of uterine fibroids and adenomyosis, thermal ablation technology offers improved fertility preservation and minimizes normal tissue injury compared to traditional surgical approaches for patients pursuing reproductive goals. In the future, thermal ablation technology will play a significantly enhanced role in preserving fertility for individuals requiring treatment for uterine fibroids and adenomyosis, guided by indications. But further research is still needed in the form of more extensive randomized prospective trials to provide stronger evidence supporting this perspective.

Integrating High-intensity Focused Ultrasound with Chemotherapy for the Treatment of Invasive Hydatidiform Mole in Reproductive-age Women.

Invasive hydatidiform mole, a form of gestational trophoblastic neoplasm in reproductive-age women, poses a significant threat to life due to its associated signs and symptoms. This case report details the management of a 24-year-old Chinese woman with no prior pregnancy history, who presented at our hospital 23 days postcurettage, experiencing persistent vaginal bleeding for 3 days. While two rounds of chemotherapy effectively reduced human chorionic gonadotropin levels, a subsequent magnetic resonance imaging (MRI) revealed suspicious growth lesions in the uterus. High-intensity focused ultrasound (HIFU) treatment was administered under ultrasound guidance, resulting in notable grayscale changes to optimize the efficacy of chemotherapy and restrict lesion progression. Subsequent ultrasound and MRI assessments during follow-up demonstrated a transparent texture in the muscle layer at the lesion site. This case suggests that the combination of chemotherapy and HIFU, guided by ultrasound, may represent a promising therapeutic approach for managing invasive hydatidiform mole.

Five-year follow-up after a single US-guided high intensity focused ultrasound treatment of breast fibroadenoma.

The aim of this study was to evaluate the long-term efficacy of a single ultrasound-guided high-intensity focused ultrasound (US-HIFU) treatment in patients with breast fibroadenoma (FA) in terms of volume and pain reduction as well as palpation findings. From december 2013 until november 2014 27 women with a symptomatic FA were treated in one HIFU-session. Follow-up visits were performed after 7 days, 6 months and 1, 2, 3 and 5 years with clinical examination and ultrasound. One year after the procedure, a core needle biopsy of the residual lesion was offered. There was a significant volume reduction 6 months after HIFU from 1083.10 to 347.13 mm3 (p < 0.0001) with a mean volume reduction ratio (VRR) of 61.63%. Thereafter the FAs showed a further, but no longer significant decrease in size. One patient with an initial incomplete ablation and histologically confirmed persistent vital cells after 1 year showed a strong regrowth after 3 years. Excluding this patient from analysis, the mean VRR at months 12, 24, 36, and 60 was 86.44%, 94.44%, 94.90%, and 97.85%, respectively. Before HIFU, 59.26% of the patients had pain (22.33/100 VAS) which decreased to 6.56/100 after 12 months and remained reduced over the 5 year follow up period. A decrease in palpability from 85.19 to 7.69% was observed within 24 months. A single HIFU intervention let to a substantial reduction in size, pain, and palpability with its most potential effect during the first 12 months. Subsequently, the observed effect remained stable over a 5 year follow up period. Incomplete initial treatment was associated with the risk of regrowth.

Model based deep learning method for focused ultrasound pathway scanning.

The primary purpose of high-intensity focused ultrasound (HIFU), a non-invasive medical therapy, is to precisely target and ablate tumors by focusing high-frequency ultrasound from an external power source. A series of ablations must be performed in order to treat a big volume of tumors, as a single ablation can only remove a small amount of tissue. To maximize therapeutic efficacy while minimizing adverse side effects such as skin burns, preoperative treatment planning is essential in determining the focal site and sonication duration for each ablation. Here, we introduce a machine learning-based approach for designing HIFU treatment plans, which makes use of a map of the material characteristics unique to a patient alongside an accurate thermal simulation. A numerical model was employed to solve the governing equations of HIFU process and to simulate the HIFU absorption mechanism, including ensuing heat transfer process and the temperature rise during the sonication period. To validate the accuracy of this numerical model, a series of tests was conducted using ex vivo bovine liver. The findings indicate that the developed models properly represent the considerable variances observed in tumor geometrical shapes and proficiently generate well-defined closed treated regions based on imaging data. The proposed strategy facilitated the formulation of high-quality treatment plans, with an average tissue over- or under-treatment rate of less than 0.06%. The efficacy of the numerical model in accurately predicting the heating process of HIFU, when combined with machine learning techniques, was validated through quantitative comparison with experimental data. The proposed approach in cooperation with HIFU simulation holds the potential to enhance presurgical HIFU plan.

Differential Analysis of Pregnancy Outcomes After Treatment of HIFU and LEEP in Patients with Cervical High-Grade Squamous Intraepithelial Lesions.

Purpose: To verify whether there is lower incidence of adverse pregnancy outcomes after high-intensity focused ultrasound (HIFU) treatment than loop electrosurgical excision procedure (LEEP) in young women of childbearing age. Patients and Methods: This retrospective cohort study enrolled 46 patients treated with HIFU and 46 patients treated with LEEP. To compare the differences between the two groups, Fisher's exact test or the Kruskal-Wallis (K-W/H) test was used in the univariate analysis, while the logistic regression method was applied for further verification. Results: Basic characteristics showed no differences between the two groups (P > 0.05) except for parity (P < 0.001). Preterm birth rates were 6.52% and 0.00% in patients with cervical high-grade squamous intraepithelial lesions (HSIL) treated with LEEP and HIFU, respectively. The incidence rates of premature rupture of membranes (PROM) were respectively 15.22% and 21.74% in the two groups. There was no significant difference in pregnancy outcomes between the two groups (P > 0.05). Conclusion: This study is the first to compare the pregnancy outcomes of patients with cervical HSIL who treated with LEEP and HIFU procedures. Both HIFU treatment and LEEP are available options for patients of reproductive age with cervical HSIL. Therefore, it is necessary to conduct prospective single-center or multicenter randomized controlled studies.

Histological characterization of HIFU lesions.

Background: High intensity focused ultrasound (HIFU) can destroy tissue by thermal ablation which may be accompanied by acoustic cavitation and/or tissue water boiling, but the biological and histological effects of these treatments have not been fully documented. Here, detailed histological analysis over time using well characterized HIFU exposures in in vivo rat livers is described.Methods: Exposures used invoked either (i) thermal, with acoustic cavitation and/or tissue water boiling or (ii) predominantly thermal damage. Cavitation activity was detected using both active and passive methods. Histological assessment involved hematoxylin and eosin (H&E), picrosirius red and immunohistochemical staining.Results: Distinct concentric damage regions were identified after HIFU exposures. The outermost ring showed a red H&E-stained rim that was characterized by hemorrhage. The adjacent inner band appeared white due to increased extracellular spaces. The morphology of the next zone depended on the exposure. Where there was no tissue acoustic cavitation/water boiling, this was the lesion center, in which heat-fixed cells were seen. Where acoustic cavitation/boiling occurred, a centermost zone with irregular holes up to several hundred microns across was seen. Cleaved caspase-3 and Hsp70 staining in the periphery of both types of HIFU exposures was seen within the outermost ring of hemorrhage, where an inflammatory response was also observed. By day 7, a distinct acellular region in the center of the HIFU lesions had been created.Conclusions: These results identify the morphological effects and elucidate the similarities and differences of HIFU-induced thermal lesions in the presence or absence of acoustic cavitation/tissue water boiling.