High-intensity Focused Ultrasound Therapy Research Articles

Focal high-intensity focused ultrasound therapy for localized prostate cancer: An interim analysis of the multinational FASST study.

High-intensity focused ultrasound (HIFU) emerged as a novel approach for the treatment of localized prostate cancer (PCa). However, prospective studies on HIFU-related outcomes and predictors of treatment failure (TF) remain scarce. We conducted a multinational prospective cohort study among patients undergoing HIFU therapy for localized, low- to intermediate-risk PCa. Follow-up data on serial prostate specific antigen (PSA), multi-parametric magnetic resonance imaging (mpMRI), targeted/systematic biopsies, adverse events and functional outcomes were collected. The primary endpoint was TF, defined as histologically confirmed PCa requiring whole-gland salvage treatment. Uni- and multi-variable adjusted hazard ratios (HRs) were calculated using Cox proportional hazard regression models. At baseline, mean (standard deviation) age was 64.14 (7.19) years, with the majority of patients showing T-stage 1 (73.9%) and International Society of Urological Pathology grading system Grade 2 (58.8%). PSA nadir (median, 1.70 ng/mL) was reached after 6 months. Of all patients recruited, 16% had clinically significant PCa, as confirmed by biopsy, of which 13.4% had TF. Notably, T-stage and number of positive cores at initial biopsy were independent predictors of TF during follow-up (HR [95% CI] 1.27 [1.02-1.59] and 5.02 [1.80-14.03], respectively). Adverse events were minimal (17% and 8% early and late adverse events, respectively), with stable or improved functional outcomes in the majority of patients. This interim analysis of a multinational study on HIFU therapy for the management of low-to-intermediate-risk PCa reveals good functional outcomes, minimal adverse events and low incidence of TF over the short-term. Data on long-term outcomes, specifically as it relates to oncological outcomes, are awaited eagerly.

Prediction of Ablation Rate for High-Intensity Focused Ultrasound Therapy of Adenomyosis in MR Images Based on Multi-model Fusion.

This study aimed to develop a model based on radiomics and deep learning features to predict the ablation rate in patients with adenomyosis undergoing high-intensity focused ultrasound (HIFU) therapy. A total of 119 patients with adenomyosis who received HIFU therapy were retrospectively analyzed. Participants were included in the training and testing queues in a 7:3 ratio. Radiomics features were extracted from T2-weighted imaging (T2WI) images, and VGG-19 was used to extract advanced deep features. An ensemble model based on multi-model fusion for predicting the efficacy of HIFU in adenomyosis was proposed, which consists of four base classifiers and was evaluated using accuracy, precision, recall, F-score, and area under the receiver operating characteristic curve (AUC). The predictive performance of the combined model combining radiomics and deep learning features outperformed the radiomics and deep learning feature models alone, with accuracy of 0.848 and 0.814 in training and test sets, and AUC of 0.916 and 0.861, respectively. Compared with the base classifiers that make up the multi-model fusion model, the fusion model also exhibited better prediction performance. The fusion model incorporating both radiomics and deep learning features had certain predictive value for the ablation rate of adenomyosis under HIFU therapy and could help select patients with adenomyosis who would benefit from HIFU therapy.

Repeated high‑intensity focused ultrasound combined with iodine‑125 seed interstitial brachytherapy offers improved quality of life and pain control for patients with advanced pancreatic cancer: A 52‑patient retrospective study.

Patients diagnosed with pancreatic cancer who have 5-year survival rates of ~5% are typically in the advanced stage. Pancreatic cancer has become the third leading cause of cancer-related death in the United States and there is still a lack of effective treatments to improve patient survival rate. Hence, the purpose of the present retrospective study was to assess the potential clinical impact of repeated high-intensity focused ultrasound (HIFU) combined with iodine-125 (125I) interstitial brachytherapy for the treatment of patients with advanced pancreatic cancer who were ineligible for or declined surgery and chemotherapy. A total of 52 patients diagnosed with advanced pancreatic cancer were included in the study. At least one course of HIFU therapy combined with percutaneous ultrasound-guided 125I seed implantation was administered to each patient. The clinical assessment included an evaluation of Karnofsky Performance Scale (KPS) score at baseline, and at 1 and 2 months after combined therapy. Pain intensity was additionally evaluated with the numerical rating score (NRS). Overall survival (OS) times and survival rates at 3, 6, 9 and 12 months after combined treatment were evaluated. Adverse events commonly associated with HIFU and 125I seed implantation were recorded, and the severity of adverse events was graded according to the Common Terminology Criteria for Adverse Events, version 4. All 52 patients received successful repeated HIFU treatment combined with 125I seed implantation and were included in the analysis of efficacy and safety. The median OS time of patients was estimated to be 13.1 months (95% CI, 11.3-14.8). The survival rates at 3, 6, 9 and 12 months were 100.0, 86.5, 61.5 and 53.8%, respectively. The mean KPS score was 62.7±6.3 at baseline, 73.7±7.9 at 1 month and 68.8±6.5 at 2 months after combined treatment. KPS score increased significantly after combined therapy. The mean NRS score was 6.7±1.6 at baseline, and 4.7±1.7 and 5.4±1.5 at 1 and 2 months after combined treatment, respectively. The number of patients with severe pain and the NRS score were both significantly lower at 1 and 2 months after 125I seed implantation compared with those at baseline. No serious complications were detected during the follow-up period. In conclusion, the present study demonstrated the survival benefit and improvement in quality of life of patients with advanced pancreatic cancer receiving repeated HIFU treatment combined with 125I interstitial brachytherapy, which may provide new ideas and methods for the treatment of pancreatic cancer.

Abdominal wall hernias following high-intensity focused ultrasound (HIFU) therapy: Three cases report

Objective: Although many studies reported the safety and efficacy of high-intensity focused ultrasound (HIFU) therapy, there are still worries about internal organ injury. However, reports of abdominal wall hernias after HIFU therapy are rare. Case report: We present three cases of abdominal wall hernias without skin injury after HIFU therapy in uterine adenomyosis or fibroids. The diagnosis was often delayed because of vague symptoms, inadequate clinical suspicion, and delayed proper image studies. Conclusion: Abdominal wall hernia should be recognized as a possible complication after HIFU and be suspected when the patient presents with unordinary abdominal swelling and/or pain that last for more than a few months after the procedure.

Safety and Efficacy of High-Intensity Focused Ultrasound and Monopolar Radiofrequency Combination Therapy for Skin Tightening: A Retrospective Study in Malaysia.

High-intensity focused ultrasound (HIFU) and monopolar radiofrequency (MRF) are common treatment modalities that have shown significant results in skin tightening. Nevertheless, the novel combination of these two treatments is new to the Malaysian landscape. Thus, this study aims to investigate the safety and efficacy of this novel combination treatment for the Malaysian population. This retrospective study included data on HIFU and MRF combination therapy for skin tightening collected from an aesthetic clinic in Johor Bahru, Malaysia from June 2018 to May 2021. Efficacy was assessed using the Global Aesthetic Improvement Scale (GAIS) and Glogau classification, while the safety of the treatment was analysed using pain scores and adverse events (AEs). A total of 56 patients with a mean age of 47.7 years old (SD 10.00) were included in this study. The majority of the patients had Fitzpatrick skin types III and IV. Most of the patients were Chinese, followed by Malay, Indian and others. Most patients (96.4%) showed clinically significant improvement in skin tightening after treatment, with 15 patients scoring 1 (very much improved) and 39 scoring 2 (improved). All patients reported transient mild erythema, with no serious AEs, such as burn, swelling, numbness or muscle weakness. Among the patients, 80% reported a pain score of 5, while 10% reported pain scores of 4 and 6. Combining HIFU with MRF therapy improved GAIS scores by 96.4%, indicating a secure and efficient skin-tightening method. Transient erythema was shown to be the most common side effect of this combination.

Evaluation of functional and oncological outcomes of localized prostate cancer after different minimally invasive therapeutic methods: A single center experience.

To study the functional and oncological results of minimally invasive treatment methods: cryoablation, brachytherapy, and high-intensity focused ultrasound (HIFU) therapy of localized prostate cancer in a single hospital. One hundred sixty patients with localized prostate cancer were treated with minimally invasive methods (53, 52, 55 patients with cryoablation, brachytherapy and HIFU therapy, respectively). Prostate-specific antigen and evaluation of post-procedure biopsies were used as an assessment. The review of functional indicators and quality of life was made with International Index of Erectile Function (IIEF-5), International Prostate Symptom Score (IPSS), maximum urinary flow rate (Qmax), quality of life (QoL) questionnaires. Patients after cryoablation showed worse results of oncological control according to positive repeat biopsies, best indicators were observed after brachytherapy. When considering the IPSS results, there were statistically significantly worse scores in the brachytherapy group in the early postoperative period, these differences do not reach statistical significance in the late period in the brachytherapy and cryoablation groups. Patients in the cryoablation group showed worse indicators of IIEF-5; in the early postoperative period; in the late follow-up period, the indicators of erectile function in patients in the cryoablation group did not statistically significantly differ from those in patients after brachytherapy. Patients after HIFU therapy showed fewer cases of de novo erectile dysfunction during the follow-up period of 3 years, higher average IIEF-5 scores, lower IPSS scores and better QoL results. The recurrence of prostate cancer was statistically significantly higher in the International Society of Urological Pathology (ISUP) 3 grade group. HIFU therapy had better urination indicators compared to other groups, that can be associated with the laser enucleation of prostatic hyperplasia. The advantage was noted in patients after HIFU therapy when comparing the parameters to the IIEF-5 thus, HIFU treatment had a better impact on patients' QoL with localized prostate cancer.

Real-Time Reconstruction of HIFU Focal Temperature Field Based on Deep Learning.

Objective and Impact Statement: High-intensity focused ultrasound (HIFU) therapy is a promising noninvasive method that induces coagulative necrosis in diseased tissues through thermal and cavitation effects, while avoiding surrounding damage to surrounding normal tissues. Introduction: Accurate and real-time acquisition of the focal region temperature field during HIFU treatment marked enhances therapeutic efficacy, holding paramount scientific and practical value in clinical cancer therapy. Methods: In this paper, we initially designed and assembled an integrated HIFU system incorporating diagnostic, therapeutic, and temperature measurement functionalities to collect ultrasound echo signals and temperature variations during HIFU therapy. Furthermore, we introduced a novel multimodal teacher-student model approach, which utilizes the shared self-expressive coefficients and the deep canonical correlation analysis layer to aggregate each modality data, then through knowledge distillation strategies, transfers the knowledge from the teacher model to the student model. Results: By investigating the relationship between the phantoms, invitro, and invivo ultrasound echo signals and temperatures, we successfully achieved real-time reconstruction of the HIFU focal 2D temperature field region with a maximum temperature error of less than 2.5 °C. Conclusion: Our method effectively monitored the distribution of the HIFU temperature field in real time, providing scientifically precise predictive schemes for HIFU therapy, laying a theoretical foundation for subsequent personalized treatment dose planning, and providing efficient guidance for noninvasive, nonionizing cancer treatment.

A theragnostic HIFU transducer and system for inherently registered imaging and therapy.

One big challenge with high intensity focused ultrasound (HIFU) is the difficulty in accurate prediction of focal location due to the complex wave propagation in heterogeneous medium even with imaging guidance. This study aims to overcome this by combining therapy and imaging guidance with one single HIFU transducer using the vibro-acoustography (VA) strategy. Based on the VA imaging method, a HIFU transducer consisting of 8 transmitting elements was proposed for therapy planning, treatment and evaluation. Inherent registration between the therapy and imaging created unique spatial consistence in HIFU transducer's focal region in the above three procedures. Performance of this imaging modality was first evaluated through in-vitro phantoms. In-vitro and ex-vivo experiments were then designed to demonstrate the proposed dual-mode system's ability in conducting accurate thermal ablation. Point spread function of the HIFU-converted imaging system had a full wave half maximum of about 1.2 mm in both directions at a transmitting frequency of 1.2 MHz, which outperformed the conventional ultrasound imaging (3.15 MHz) in in-vitro situation. Image contrast was also tested on the in-vitro phantom. Various geometric patterns could be accurately 'burned out' on the testing objects by the proposed system both in vitro and ex vivo. Implementation of imaging and therapy with one HIFU transducer in this manner is feasible and it has potential as a novel strategy for addressing the long-standing problem in the HIFU therapy, possibly pushing this non-invasive technique forward towards wider clinical applications.

Long-term Efficacy of Fibroid Devascularization with Ultrasound-Guided High-Intensity Focused Ultrasound

High-intensity focused ultrasound (HIFU) has been increasingly used for treatment of uterine leiomyoma. The superiority of HIFU therapy targeting uterine leiomyoma blood vessels, however, still needs to be further explored. This study aims to evaluate the long-term efficacy of fibroid devascularization with ultrasound-guided HIFU (USgHIFU) and the effects of treatment on the ovarian reserve and endometrial injury. Fibroid devascularization was assessed with the Adler grade obtained by color Doppler flow imagingand power Doppler imaging (PDI). The targeted vessels were covered and then sonicated by HIFU focal spots. The patients were followed up at 1 month, 3 months, 6 months, 1 year, 2 years and 3 years after treatment. Adverse effects and complications were recorded. The non-perfusion volume rate (NPVR), fibroid volume shrinkage rate (FVSR), Adler Grade, symptom severity score (SSS) and uterine fibroid symptom and quality of life (UFS-QOL) were evaluated. Adverse events (AEs)were recorded. In Center 1, the enrolled patients completed the anti-Müllerian hormone (AMH) test before and at 6 months after treatment. A total of 117 eligible patients were consecutively enrolled to receive interventions and follow-up evaluations of the three centers from January 2019 to May 2023. The 1-month and 6-monthNPVRs were 66.60%±33.14% and 51.12%±39.84%, respectively. The mean FVSRs at 1 month and 6 months after treatment were 38.20% and 43.89%, respectively. No significant difference was observed in AMH levels before and after treatment (p>0.05). No irreversible endometrial injury was observed in MR images after HIFU treatment. No significant difference was observed in both 1-month and 6-monthFVSRs among Center 1, 2 and 3 (p>0.05). No severe AEs occurred. For long-term outcomes, significant differences were observed in Adler grade, FV, FVSR, SSS, reduction in SSSand UFS-QOL before and after treatment (p<0.001) whereas no significant difference was observed in Adler grade among 3 months, 1 year, 2 years and 3 years after treatment (p>0.05). The SSSs were reduced by 33.42% at 1 year, 42.32% at 2 years and 52.46% at 3 years after treatment. For patients with uterine fibroids, USgHIFU-induced devascularization is a safe and effective treatment option. It has little effect on ovarian function and the endometrial injury is reversible, which could be attractive for patients who plan to become pregnant.

Sequential high-intensity focused ultrasound treatment combined with chemotherapy for inoperable pancreatic cancer: a retrospective analysis for prognostic factors and survival outcomes

Objective To evaluate the effect of HIFU (High-Intensity Focused Ultrasound) therapy on the survival and prognosis of patients with inoperable pancreatic cancer, and the clinical application of serological prognostic indicators. Methods We retrospectively analyzed the clinicopathological features, laboratory tests and follow-ups of 192 patients. Among the patients, 57 were treated with HIFU prior to chemotherapy (HIFU-priority), and 135 patients received chemotherapy followed by HIFU (HIFU-second). Univariate and multivariate Cox regression analysis was used to determine the prognostic value of tumor inflammation-related serological markers. A nomogram model was established based on the identified prognostic factors. Results Univariate analysis showed that receiving the treatment regimen in HIFU-priority was a significant protective factor for overall survival (OS, p < 0.001). Tumor stage, high C-reactive protein (CRP), high gamma-glutamyl transferase(γGT) high carbohydrate antigen 125 (CA125), high neutrophil-to-lymphocyte ratio (NLR), high lymphocyte-to-monocyte ratio (LMR) and liver metastasis were significant risk factors for poor prognosis (p < 0.05). CRP combined with normal tumor marker CA125 (CRP + CA125) was associated with longer OS (p = 0.005). Multivariate analysis shows that HIFU-priority is a protective factor for OS (Hazard Ratio, HR: 0.38; 95% confidence interval(CI): 0.25-0.57), tumor stage (HR: 1.61; 95% CI: 1.12-2.31), CRP + CA125 (HR: 1.46; 95% CI: 1.02-2.08) and γGT (HR: 1.44; 95% CI: 1.04-1.98) are risk factors for OS and serve as independent prognostic factors in the nomogram. Conclusion Early application of HIFU treatment improves the OS of patients with inoperable pancreatic cancer. CRP + CA125 and γGT are independent prognostic factors.

Safety of Sonazoid in Assisting High-Intensity Focused Ultrasound Ablation Therapy for Advanced Liver Malignant Lesions: A Single-Arm Clinical Study

The aim of the study described here was to evaluate the safety of Sonazoid-assisted high-intensity focused ultrasound (HIFU) in the treatment of advanced malignant liver lesions. A single-arm study was designed to enroll participants who were diagnosed with advanced primary liver cancer or liver metastases and proposed to receive Sonazoid assistance during HIFU treatment. Serological examination was conducted within 1 wk, and side effects in each patient were monitored for 1 mo. To evaluate therapeutic efficacy, the contrast-enhanced magnetic resonance imaging was performed 1 mo after treatment, and short-term follow-up was conducted a year later. A total of 17 participants (12 male, 5 female) with an average age of 58 y (range: 46-73 y) were enrolled, including 11 patients with hepatocellularcarcinoma, 2 patients with hepaticmetastasis and 4 patients with cholangiocarcinoma. The total volume of tumor mass was 111.82 (11.01-272.30) cm3. The average total ablation time for a patient was 2021 ± 1030 s, and the energy efficiency factor was 5979.7 (3108.0, 45634.5) J/cm3. Immediately after HIFU treatment, 1 patient (5.9%) achieved complete response (CR), 4 patients (23.5%) had a moderate response, 8 patients (47.1%) had partial reperfusion and 4 patients (23.5%) had stable disease (SD). The average ablation rate for all the tumors was 51.5 ± 26.7%. The level of glutamic-pyruvic transaminase (ALT) was mildly increased in 71.6% (12/17) of patients after HIFU therapy. Mean ALT values before and after treatment were 22 (14, 35) U/L and 36 (25, 41) U/L, respectively (Z=1.947, p=0.051). Mild or obvious edema in skin and subcutaneous soft tissues were observed in 76.5% of patients, but no serious side effects were found. Twelve months after treatment, the follow-up results revealed that 1 patient (5.8%) achieved a CR, 8 patients (47.1%) had SD and 8 patients (47.1%) had progressive disease. The estimated median time to progression was 11 mo after treatment, with a 95% confidence interval of 6, 11 for all involved patients. Use of Sonazoid is safe and feasible for improving HIFU ablation efficiency during the treatment of advanced malignant liver lesions. The therapeutic efficacy of Sonazoid-assisted HIFU needs to be explored in additional controlled clinical investigations.

Deep-Learning-Based High-Intensity Focused Ultrasound Lesion Segmentation in Multi-Wavelength Photoacoustic Imaging.

Photoacoustic (PA) imaging can be used to monitor high-intensity focused ultrasound (HIFU) therapies because ablation changes the optical absorption spectrum of the tissue, and this change can be detected with PA imaging. Multi-wavelength photoacoustic (MWPA) imaging makes this change easier to detect by repeating PA imaging at multiple optical wavelengths and sampling the optical absorption spectrum more thoroughly. Real-time pixel-wise classification in MWPA imaging can assist clinicians in monitoring HIFU lesion formation and will be a crucial milestone towards full HIFU therapy automation based on artificial intelligence. In this paper, we present a deep-learning-based approach to segment HIFU lesions in MWPA images. Ex vivo bovine tissue is ablated with HIFU and imaged via MWPA imaging. The acquired MWPA images are then used to train and test a convolutional neural network (CNN) for lesion segmentation. Traditional machine learning algorithms are also trained and tested to compare with the CNN, and the results show that the performance of the CNN significantly exceeds traditional machine learning algorithms. Feature selection is conducted to reduce the number of wavelengths to facilitate real-time implementation while retaining good segmentation performance. This study demonstrates the feasibility and high performance of the deep-learning-based lesion segmentation method in MWPA imaging to monitor HIFU lesion formation and the potential to implement this method in real time.

The Applications of High-Intensity Focused Ultrasound (HIFU) Ablative Therapy in the Treatment of Primary Breast Cancer: A Systematic Review.

This study evaluates the role of high-intensity focused ultrasound (HIFU) ablative therapy in treating primary breast cancer. PubMed and Scopus databases were searched according to the PRISMA guidelines to identify studies from 2002 to November 2022. Eligible studies were selected based on criteria such as experimental study type, the use of HIFU therapy as a treatment for localised breast cancer with objective clinical evaluation, i.e., clinical, radiological, and pathological outcomes. Nine studies were included in this study. Two randomised controlled trials and seven non-randomised clinical trials fulfilled the inclusion criteria. The percentage of patients who achieved complete (100%) coagulation necrosis varied from 17% to 100% across all studies. Eight of the nine studies followed the treat-and-resect protocol in which HIFU-ablated tumours were surgically resected for pathological evaluation. Most breast cancers were single, solitary, and palpable breast tumours. Haematoxylin and eosin stains used for histopathological evaluation showed evidence of coagulation necrosis. Radiological evaluation by MRI showed an absence of contrast enhancement in the HIFU-treated tumour and 1.5 to 2 cm of normal breast tissue, with a thin peripheral rim of enhancement indicative of coagulation necrosis. All studies did not report severe complications, i.e., haemorrhage and infection. Common complications related to HIFU ablation were local mammary oedema, pain, tenderness, and mild to moderate burns. Only one third-degree burn was reported. Generally, the cosmetic outcome was good. The five-year disease-free survival rate was 95%, as reported in two RCTs. HIFU ablation can induce tumour coagulation necrosis in localised breast cancer, with a favourable safety profile and cosmetic outcome. However, there is variable evidence of complete coagulation necrosis in the HIFU-treated tumour. Histopathological evidence of coagulation necrosis has been inconsistent, and there is no reliable radiological modality to assess coagulation necrosis confidently. Further exploration is needed to establish the accurate ablation margin with a reliable radiological modality for treatment and follow-up. HIFU therapy is currently limited to single, palpable breast tumours. More extensive and randomised clinical trials are needed to evaluate HIFU therapy for breast cancer, especially where the tumour is left in situ.

Microbubble-enhanced HIFU therapy for vascularized tumors using Levovist contrast agent

High-intensity focused ultrasound (HIFU) has enormous potential in the treatment of cancers; however, there is still plenty of challenges associated with using acoustic energy to treat vascularized tumors. Among them, the blood flow cooling reduces the treatment efficiency significantly and results in a long treatment period. Various studies have shown that the HIFU improves cancer treatment by targeting the cancer tissue. Unfortunately, the issues related to vascularization have remained unsolved. In the present study, through a novel approach, a promising strategy is proposed by injecting Levovist contrast agent solution in the vascularized tumor. The complicated interaction between the Levovist microbubble (MB) and the ultrasonic waves is innovatively modeled by considering the coupled effect of HIFU wave propagation, fluid flow, MB oscillations, and transient heat transfer for a multi-layered porous model of liver tumor. The proposed strategy is evaluated in terms of the extent of irreversible TD and treatment duration. The results reflect the role of MB oscillation on the temperature rise, as injection of a 2 μm-MB during 15 s of HIFU sonication increases the temperature by 9.61% compared to no-MB condition. Meanwhile, the MB oscillation advances the irreversible damage, and tumor cells undergo thermal ablation by 48.94% earlier than the case with no-MB agent. Additionally, it is found that the MB size has a substantial effect on the amount of heat deposition. At an operating condition of 1.25 MHz and 10 W, the viscous power deposition for a 2 μm-MB is3.81 mW, while for a 50 μm-MB, it is reduced to 0.96 mW. On the contrary, the heat source due to the secondary acoustic power deposition is proportional to the MB size, as it increases from 60.5 mW for a 2 μm-MB to 180 mW for a 50 μm-MB, demonstrating a 2.97-fold increase. Eventually, an assessment of the extent of the necrotic area shows an increase at all frequencies by injecting an MB into the tumor area. At an operating condition of 1.5 MHz, oscillation of 2 μm-MB expands the necrotic area by 4.01% compared to the no-MB condition. Based on the obtained results, the injection of Levovist contrast agent solution in the vascularized tumor can be regarded as an effective method for reducing the treatment time and avoiding several sonication.

Effect of pulse parameters on ablation efficiency in dual-frequency HIFU therapy

High-intensity focused ultrasound (HIFU) has now been widely used to ablate various benign and malignant tumors. But it is still critical to increase the ablation efficiency in many clinical applications. Dual-frequency HIFU has been proven to be more efficient in ablation, but the principle on selecting the pulse parameters in this method remains to be explored. In this study, the in vitro lesion areas under different pulse repetition frequencies (PRFs), duty ratios, and frequency differences were compared, cavitation activity was also monitored during HIFU exposure. The results showed that different pulse parameters caused different types of lesions. In HIFU therapy, those pulse parameters that maximize the thermal effect, reduce heat dissipation and generate sufficient cavitation activities should be considered. But the method of evaluating or predicting the damage by using the cavitation dose is only applicable to mechanical damage.

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

ABSTRACT 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.

Effect of HIFU-Induced Thermal Ablation in Numerical Breast Phantom

Breast cancer is a leading cause of cancer-related deaths in women, and treatment involved invasive surgery such as lumpectomy. In the last decade, a non-invasive, non-contact high-intensity focused ultrasound (HIFU) therapy was developed for treatment with promising results. However, its success rate depends on patient selection, tissue heterogeneities, HIFU operational parameters, and even imaging techniques. In this emerging field, computer simulations can provide us with a much-needed platform to learn, test, and deduce results virtually before conducting experiments. In this study, we used three different classes of anatomically realistic numerical breast phantoms from clinical contrast-enhanced magnetic resonance imaging (MRI) data, including scattered-, heterogeneous-, and extremely dense-type breasts. Upon assigning the appropriate acoustic and optical parameters to the tissues within, we simulated HIFU propagation by using the k-Wave toolbox in MATLAB and compared the changes introduced in the three types of breasts. It was found that scattered-type breast was best-suited for HIFU therapy. Furthermore, we simulated light-beam propagation with the ValoMC toolbox in MATLAB after introducing the lesion to compare the distribution of the initial pressure generated via the photoacoustic effect. This simulation study will be of significant clinical impact, especially in the study and management of HIFU-based treatments, which are individual/tissue-selective in nature.

Review of Robot-Assisted HIFU Therapy

This paper provides an overview of current robot-assisted high-intensity focused ultrasound (HIFU) systems for image-guided therapies. HIFU is a minimally invasive technique that relies on the thermo-mechanical effects of focused ultrasound waves to perform clinical treatments, such as tumor ablation, mild hyperthermia adjuvant to radiation or chemotherapy, vein occlusion, and many others. HIFU is typically performed under ultrasound (USgHIFU) or magnetic resonance imaging guidance (MRgHIFU), which provide intra-operative monitoring of treatment outcomes. Robot-assisted HIFU probe manipulation provides precise HIFU focal control to avoid damage to surrounding sensitive anatomy, such as blood vessels, nerve bundles, or adjacent organs. These clinical and technical benefits have promoted the rapid adoption of robot-assisted HIFU in the past several decades. This paper aims to present the recent developments of robot-assisted HIFU by summarizing the key features and clinical applications of each system. The paper concludes with a comparison and discussion of future perspectives on robot-assisted HIFU.

MP73-02 FOCAL THERAPY - 7 YEARS EXPERIENCE WITH FOCAL HIGH INTENSITY FOCUSED ULTRASOUND IN 164 PATIENTS WITH PROSTATE CANCER: SINGLE CENTER RESULTS

You have accessJournal of UrologyCME1 Apr 2023MP73-02 FOCAL THERAPY - 7 YEARS EXPERIENCE WITH FOCAL HIGH INTENSITY FOCUSED ULTRASOUND IN 164 PATIENTS WITH PROSTATE CANCER: SINGLE CENTER RESULTS Yamini Nagaraj, Fabian Falkenbach, Valia Veleva, Randi Marisa Pose, Jonas Ekrutt, Raisa Abrams-Pompe, Jaideep Ratkal, Pierre Tennstedt, Derya Tilki, Hans Heinzer, Markus Graefen, and Georg Salomon Yamini NagarajYamini Nagaraj More articles by this author , Fabian FalkenbachFabian Falkenbach More articles by this author , Valia VelevaValia Veleva More articles by this author , Randi Marisa PoseRandi Marisa Pose More articles by this author , Jonas EkruttJonas Ekrutt More articles by this author , Raisa Abrams-PompeRaisa Abrams-Pompe More articles by this author , Jaideep RatkalJaideep Ratkal More articles by this author , Pierre TennstedtPierre Tennstedt More articles by this author , Derya TilkiDerya Tilki More articles by this author , Hans HeinzerHans Heinzer More articles by this author , Markus GraefenMarkus Graefen More articles by this author , and Georg SalomonGeorg Salomon More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003341.02AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Focal therapy aims to selectively ablate tumor lesions and preserve prostate tissue, thus minimizing side effect whilst providing oncological control. The experience of the first 2 years lead to improved diagnostic work up prior to HIFU with better patient selection and less tumor recurrence in the following 5 years. The strong recommendation of control biopsy in the follow up, lead to a reliable and early selection of patients requiring salvage therapy and thus improving oncological results. METHODS: This is a prospective evaluation of 164 patients undergoing focal high intensity focused ultrasound (HIFU) in our institution from July 2015 till June 2022. Patients were required to have a unilateral Gleason score (GS) ≤7, stage T1 or T2 and a PSA level of≤15 ng/ml. Tumor localization was done using multiparametric MRI followed by mainly transrectal targeted and systematic biopsies of any lesion PI-RADS≥3. Systematic biopsy was recommended 1 year after HIFU with PSA levels every 3 months. An MRI was scheduled at 3 years post HIFU. In the control biopsy significant cancer recurrence was defined as >3mm GS 3+3, >3 positive cores or any GS≥3+4; these patients were offered further treatment; either a repeat HIFU, radical prostatectomy (RP) or radiation therapy (RT). Urinary and erectile function were assessed using validated questionnaires. RESULTS: Median PSA prior to HIFU was 6 ng/ml, the median follow-up was 61 months. 38% of the patients had low, 60% intermediate and 2% high risk disease. Median PSA level 2 years post HIFU was 1.9 ng/ml. Of the 119 control biopsies 50% had no evidence of tumor, 36% had insignificant tumor evidence and 14 % showed evidence of significant prostate cancer according to the above defined criteria. Significant infield recurrence occurred in 6 patients (4%) and significant outfield recurrence was seen in 10 patients (6%). 5 patients received a repeat HIFU, 4 patients a RT and 7 had a RP. There were no cases of distant metastasis, no need for palliative antiandrogen therapy (ADT) and no major complications. Urinary continence and erectile function were preserved in 99.5% and 85% respectively. CONCLUSIONS: At 7 years, HIFU therapy showed efficient oncological control rates with a radical treatment free survival rate of 93%. Significant infield recurrence was seen in 4% and significant outfield recurrence in 6% of patients. There was no distant metastasis and no need for palliative ADT. HIFU is associated with excellent preservation of continence and erectile function with very low morbidity. Source of Funding: Non funded © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e1034 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Yamini Nagaraj More articles by this author Fabian Falkenbach More articles by this author Valia Veleva More articles by this author Randi Marisa Pose More articles by this author Jonas Ekrutt More articles by this author Raisa Abrams-Pompe More articles by this author Jaideep Ratkal More articles by this author Pierre Tennstedt More articles by this author Derya Tilki More articles by this author Hans Heinzer More articles by this author Markus Graefen More articles by this author Georg Salomon More articles by this author Expand All Advertisement PDF downloadLoading ...

Array-based high-intensity focused ultrasound therapy system integrated with real-time ultrasound and photoacoustic imaging.

High-intensity focused ultrasound (HIFU) is a promising non-invasive therapeutic technique in clinical applications. Challenges in stimulation or ablation HIFU therapy are to accurately target the treatment spot, flexibly deliver or fast-move focus points in the treatment region, and monitor therapy progress in real-time. In this paper, we develop an array-based HIFU system integrated with real-time ultrasound (US) and photoacoustic (PA) imaging. The array-based HIFU transducer can be dynamically focused in a lateral range of ∼16 mm and an axial range of ∼40 mm via electronically adjusting the excitation phase map. To monitor the HIFU therapy progress in real-time, sequential HIFU transmission, PA imaging, PA thermometry, and US imaging are implemented to display the dual-modal images and record the local temperature changes. Co-registered dual-modal images show structural and functional information and thus can guide the HIFU therapy for precise positioning and dosage control. Besides therapy, the multi-element HIFU transducer can also be used to acquire US images to precisely align the imaging coordinates with the HIFU coordinates. Phantom experiments validate the precise and dynamic steering capability of HIFU ablation. We also show that dual-modal imaging can guide HIFU in the designated region and monitor the temperature in biological tissue in real-time.