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Maxwell AD. Revealing physical interactions of ultrasound waves with the body through photoelasticity imaging. OPTICS AND LASERS IN ENGINEERING 2024; 181:108361. [PMID: 39219742 PMCID: PMC11361005 DOI: 10.1016/j.optlaseng.2024.108361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Ultrasound is a ubiquitous technology in medicine for screening, diagnosis, and treatment of disease. The functionality and efficacy of different ultrasound modes relies strongly on our understanding of the physical interactions between ultrasound waves and biological tissue structures. This article reviews the use of photoelasticity imaging for investigating ultrasound fields and interactions. Physical interactions are described for different ultrasound technologies, including those using linear and nonlinear ultrasound waves, as well as shock waves. The use of optical modulation of light by ultrasound is presented for shadowgraphic and photoelastic techniques. Investigations into shock wave and burst wave lithotripsy using photoelastic methods are summarized, along with other endoscopic forms of lithotripsy. Photoelasticity in soft tissue surrogate materials is reviewed, and its deployment in investigating tissue-bubble interactions, generated ultrasound waves, and traumatic brain injury, are discussed. With the continued growth of medical ultrasound, photoelasticity imaging can play a role in elucidating the physical mechanisms leading to useful bioeffects of ultrasound for imaging and therapy.
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Affiliation(s)
- Adam D Maxwell
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
- Department of Urology, University of Washington School of Medicine, Seattle, WA 98195
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Kumar YN, Singh Z, Wang YN, Kanabolo D, Chen L, Bruce M, Vlaisavljevich E, True L, Maxwell AD, Schade GR. A comparative study of histotripsy parameters for the treatment of fibrotic ex-vivo human benign prostatic hyperplasia tissue. Sci Rep 2024; 14:20365. [PMID: 39223181 PMCID: PMC11369199 DOI: 10.1038/s41598-024-71163-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2024] [Accepted: 08/26/2024] [Indexed: 09/04/2024] Open
Abstract
Histotripsy is a noninvasive focused ultrasound therapy that mechanically fractionates tissue to create well-defined lesions. In a previous clinical pilot trial to treat benign prostatic hyperplasia (BPH), histotripsy did not result in consistent objective improvements in symptoms, potentially because of the fibrotic and mechanically tough nature of this tissue. In this study, we aimed to identify the dosage required to homogenize BPH tissue by different histotripsy modalities, including boiling histotripsy (BH) and cavitation histotripsy (CH). A method for histotripsy lesion quantification via entropy (HLQE) analysis was developed and utilized to quantify lesion area of the respective treatments. These data were correlated to changes in mechanical stiffness measured by ultrasound shear-wave elastography before and after treatment with each parameter set and dose. Time points corresponding to histologically observed complete lesions were qualitatively evaluated and quantitatively measured. For the BH treatment, complete lesions occurred with > = 30 s treatment time, with a corresponding maximum reduction in stiffness of -90.9 ± 7.2(s.d.)%. High pulse repetition frequency (PRF) CH achieved a similar reduction to that of BH at 288 s (-91.6 ± 6.0(s.d.)%), and low-PRF CH achieved a (-82.1 ± 5.1(s.d.)%) reduction in stiffness at dose > = 144 s. Receiver operating characteristic curve analysis showed that a > ~ 75% reduction in stiffness positively correlated with complete lesions observed histologically, and can provide an alternative metric to track treatment progression.
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Affiliation(s)
- Yashwanth Nanda Kumar
- Center for Industrial and Medical Ultrasound, University of Washington, Seattle, 98105, USA.
| | - Zorawar Singh
- Department of Urology, University of Washington, Seattle, 98195, USA
| | - Yak-Nam Wang
- Center for Industrial and Medical Ultrasound, University of Washington, Seattle, 98105, USA
| | - Diboro Kanabolo
- Department of Urology, University of Washington, Seattle, 98195, USA
| | - Lucas Chen
- Department of Urology, University of Washington, Seattle, 98195, USA
| | - Matthew Bruce
- Center for Industrial and Medical Ultrasound, University of Washington, Seattle, 98105, USA
| | - Eli Vlaisavljevich
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, 24061, USA
| | - Lawrence True
- Department of Pathology, University of Washington, Seattle, 98195, USA
| | - Adam D Maxwell
- Center for Industrial and Medical Ultrasound, University of Washington, Seattle, 98105, USA
- Department of Urology, University of Washington, Seattle, 98195, USA
| | - George R Schade
- Department of Urology, University of Washington, Seattle, 98195, USA
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Lafond M, Payne A, Lafon C. Therapeutic ultrasound transducer technology and monitoring techniques: a review with clinical examples. Int J Hyperthermia 2024; 41:2389288. [PMID: 39134055 PMCID: PMC11375802 DOI: 10.1080/02656736.2024.2389288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 07/02/2024] [Accepted: 08/01/2024] [Indexed: 09/07/2024] Open
Abstract
The exponential growth of therapeutic ultrasound applications demonstrates the power of the technology to leverage the combinations of transducer technology and treatment monitoring techniques to effectively control the preferred bioeffect to elicit the desired clinical effect.Objective: This review provides an overview of the most commonly used bioeffects in therapeutic ultrasound and describes existing transducer technologies and monitoring techniques to ensure treatment safety and efficacy.Methods and materials: Literature reviews were conducted to identify key choices that essential in terms of transducer design, treatment parameters and procedure monitoring for therapeutic ultrasound applications. Effective combinations of these options are illustrated through descriptions of several clinical indications, including uterine fibroids, prostate disease, liver cancer, and brain cancer, that have been successful in leveraging therapeutic ultrasound to provide effective patient treatments.Results: Despite technological constraints, there are multiple ways to achieve a desired bioeffect with therapeutic ultrasound in a target tissue. Visualizations of the interplay of monitoring modality, bioeffect, and applied acoustic parameters are presented that demonstrate the interconnectedness of the field of therapeutic ultrasound. While the clinical indications explored in this review are at different points in the clinical evaluation path, based on the ever expanding research being conducted in preclinical realms, it is clear that additional clinical applications of therapeutic ultrasound that utilize a myriad of bioeffects will continue to grow and improve in the coming years.Conclusions: Therapeutic ultrasound will continue to improve in the next decades as the combination of transducer technology and treatment monitoring techniques will continue to evolve and be translated in clinical settings, leading to more personalized and efficient therapeutic ultrasound mediated therapies.
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Affiliation(s)
- Maxime Lafond
- LabTAU, INSERM, Centre Léon Bérard, Université, Lyon, France
| | - Allison Payne
- Department of Radiology and Imaging Sciences, University of UT, Salt Lake City, UT, USA
| | - Cyril Lafon
- LabTAU, INSERM, Centre Léon Bérard, Université, Lyon, France
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Yang S, Zemzemi C, Escudero DS, Vela DC, Haworth KJ, Holland CK. Histotripsy and Catheter-Directed Lytic: Efficacy in Highly Retracted Porcine Clots In Vitro. ULTRASOUND IN MEDICINE & BIOLOGY 2024; 50:1167-1177. [PMID: 38777639 DOI: 10.1016/j.ultrasmedbio.2024.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 04/02/2024] [Accepted: 04/05/2024] [Indexed: 05/25/2024]
Abstract
OBJECTIVE Standard treatment for deep vein thrombosis (DVT) involves catheter-directed anticoagulants or thrombolytics, but the chronic thrombi present in many DVT cases are often resistant to this therapy. Histotripsy has been found to be a promising adjuvant treatment, using the mechanical action of cavitating bubble clouds to enhance thrombolytic activity. The objective of this study was to determine if histotripsy enhanced recombinant tissue plasminogen activator (rt-PA) thrombolysis in highly retracted porcine clots in vitro in a flow model of occlusive DVT. METHODS Highly retracted porcine whole blood clots were treated for 1 h with either catheter-directed saline (negative control), rt-PA (lytic control), histotripsy, DEFINITY and histotripsy or the combination of rt-PA and histotripsy with or without DEFINITY. Five-cycle, 1.5 MHz histotripsy pulses with a peak negative pressure of 33.2 MPa and pulse repetition frequency of 40 Hz were applied along the clot. B-Mode and passive cavitation images were acquired during histotripsy insonation to monitor bubble activity. RESULTS Clots subjected to histotripsy with and without rt-PA exhibited greater thrombolytic efficacy than controls (7.0% flow recovery or lower), and histotripsy with rt-PA was more efficacious than histotripsy with saline (86.1 ± 10.2% compared with 61.7 ± 19.8% flow recovery). The addition of DEFINITY to histotripsy with or without rt-PA did not enhance either thrombolytic efficacy or cavitation dose. Cavitation dose generally did not correlate with thrombolytic efficacy. CONCLUSION Enhancement of thrombolytic efficacy was achieved using histotripsy, with and without catheter-directed rt-PA, in the presence of physiologic flow. This suggests these treatments may be effective as therapy for DVT.
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Affiliation(s)
- Shumeng Yang
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA.
| | - Chadi Zemzemi
- Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, USA
| | | | - Deborah C Vela
- Cardiovascular Pathology, Texas Heart Institute, Houston, TX, USA
| | - Kevin J Haworth
- Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, USA; Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA
| | - Christy K Holland
- Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, USA; Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA
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Wang M, Zhang W, Chen Z, Paulus YM, Wang X, Yang X. Real-Time Cavitation Monitoring During Optical Coherence Tomography Guided Photo-Mediated Ultrasound Therapy of the Retina. IEEE Trans Biomed Eng 2024; 71:2473-2482. [PMID: 38478443 PMCID: PMC11257808 DOI: 10.1109/tbme.2024.3377115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
OBJECTIVE Photo-mediated ultrasound therapy (PUT) is a novel antivascular therapeutic modality based on cavitation-induced bioeffects. During PUT, synergistic combinations of laser pulses and ultrasound bursts are used to remove the targeted microvessels selectively and precisely without harming nearby tissue. In the current study, an integrated system combining PUT and spectral domain optical coherence tomography (SD-OCT) was developed, where the SD-OCT system was used to guide PUT by detecting cavitation in real time in the retina of the eye. METHOD We first examined the capability of SD-OCT in detecting cavitation on a vascular-mimicking phantom and compared the results with those from a passive cavitation detector. The performance of the integrated system in treatment of choroidal microvessels was then evaluated in rabbit eyes in vivo. RESULTS During the in vivo PUT experiments, several biomarkers at the subretinal layer in the rabbit eye were identified on OCT images. The findings indicate that, by evaluating biomarkers of treatment effect, real-time SD-OCT monitoring could help to avoid micro-hemorrhage, which is a potential major side effect. CONCLUSION Real-time OCT monitoring can thus improve the safety and efficiency of PUT in removing the retinal and choroidal microvasculature.
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Kumar YN, Singh Z, Wang YN, Kanabolo D, Chen L, Bruce M, Vlaisavljevich E, True L, Maxwell AD, Schade GR. A Comparative Study of Histotripsy Parameters for the Treatment of Fibrotic ex-vivo Human Benign Prostatic Hyperplasia Tissue. RESEARCH SQUARE 2024:rs.3.rs-4549536. [PMID: 39011101 PMCID: PMC11247946 DOI: 10.21203/rs.3.rs-4549536/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/17/2024]
Abstract
Histotripsy is a noninvasive focused ultrasound therapy that mechanically fractionates tissue to create well-defined lesions. In a previous clinical pilot trial to treat benign prostatic hyperplasia (BPH), histotripsy did not result in consistent objective improvements in symptoms, potentially because of the fibrotic and mechanically tough nature of this tissue. In this study, we aimed to identify the dosage required to homogenize BPH tissue by different histotripsy modalities, including boiling histotripsy (BH) and cavitation histotripsy (CH). A method for histotripsy lesion quantification via entropy (HLQE) analysis was developed and utilized to quantify lesion area of the respective treatments. These data were correlated to changes in mechanical stiffness measured by ultrasound shear-wave elastography before and after treatment with each parameter set and dose. Time points corresponding to histologically observed complete lesions were qualitatively evaluated and quantitatively measured. For the BH treatment, complete lesions occurred with >=30s treatment time, with a corresponding maximum reduction in stiffness of -90.9±7.2(s.d.)%. High pulse repetition frequency (PRF) CH achieved a similar reduction to that of BH at 288s (-91.6±6.0(s.d.)%), and low-PRF CH achieved a (-82.1±5.1(s.d.)%) reduction in stiffness at dose >=144s. Receiver operating characteristic curve analysis showed that a >~75% reduction in stiffness positively correlated with complete lesions observed histologically, and can provide an alternative metric to track treatment progression.
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Xu Z, Khokhlova TD, Cho CS, Khokhlova VA. Histotripsy: A Method for Mechanical Tissue Ablation with Ultrasound. Annu Rev Biomed Eng 2024; 26:141-167. [PMID: 38346277 DOI: 10.1146/annurev-bioeng-073123-022334] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
Histotripsy is a relatively new therapeutic ultrasound technology to mechanically liquefy tissue into subcellular debris using high-amplitude focused ultrasound pulses. In contrast to conventional high-intensity focused ultrasound thermal therapy, histotripsy has specific clinical advantages: the capacity for real-time monitoring using ultrasound imaging, diminished heat sink effects resulting in lesions with sharp margins, effective removal of the treated tissue, a tissue-selective feature to preserve crucial structures, and immunostimulation. The technology is being evaluated in small and large animal models for treating cancer, thrombosis, hematomas, abscesses, and biofilms; enhancing tumor-specific immune response; and neurological applications. Histotripsy has been recently approved by the US Food and Drug Administration to treat liver tumors, with clinical trials undertaken for benign prostatic hyperplasia and renal tumors. This review outlines the physical principles of various types of histotripsy; presents major parameters of the technology and corresponding hardware and software, imaging methods, and bioeffects; and discusses the most promising preclinical and clinical applications.
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Affiliation(s)
- Zhen Xu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA;
| | - Tatiana D Khokhlova
- Applied Physics Laboratory, University of Washington, Seattle, Washington, USA
| | - Clifford S Cho
- Department of Surgery, University of Michigan, Ann Arbor, Michigan, USA
| | - Vera A Khokhlova
- Department of Acoustics, Lomonosov Moscow State University, Moscow, Russia
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Ponomarchuk EM, Rosnitskiy PB, Tsysar SA, Khokhlova TD, Karzova MM, Kvashennikova AV, Tumanova KD, Kadrev AV, Buravkov SV, Trakhtman PE, Starostin NN, Sapozhnikov OA, Khokhlova VA. Elastic Properties of Aging Human Hematoma Model In Vitro and Its Susceptibility to Histotripsy Liquefaction. ULTRASOUND IN MEDICINE & BIOLOGY 2024; 50:927-938. [PMID: 38514363 DOI: 10.1016/j.ultrasmedbio.2024.02.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 02/10/2024] [Accepted: 02/26/2024] [Indexed: 03/23/2024]
Abstract
OBJECTIVE Tissue susceptibility to histotripsy disintegration has been reported to depend on its elastic properties. This work was aimed at investigation of histotripsy efficiency for liquefaction of human hematomas, depending on their stiffness and degree of retraction over time (0-10 d). METHODS As an in vitro hematoma model, anticoagulated human blood samples (200 mL) were recalcified at different temperatures. In one set of samples, the shear modulus was measured by shear wave elastography during blood clotting at 10℃, 22℃ and 37℃, and then daily during further aging. The ultrastructure of the samples was analyzed daily with scanning electron microscopy (SEM). Another set of blood samples (50-200 mL) were recalcified at 37℃ for density and retraction measurements over aging and exposed to histotripsy at varying time points. Boiling histotripsy (2.5 ms pulses) and hybrid histotripsy (0.2 ms pulses) exposures (2 MHz, 1% dc, P+/P-/As = 182/-27/207 MPa in situ) were used to produce either individual cigar-shaped or volumetric (0.8-3 mL) lesions in samples incubated for 3 h, 5 d and 10 d. The obtained lesions were sized, then the lysate aspirated under B-mode guidance was analyzed ultrastructurally and diluted in distilled water for sizing of residual fragments. RESULTS It was found that clotting time decreased from 113 to 25 min with the increase in blood temperature from 10℃ to 37℃. The shear modulus increased to 0.53 ± 0.17 kPa during clotting and remained constant within 8 d of incubation at 2℃. Sample volumes decreased by 57% because of retraction within 10 d. SEM revealed significant echinocytosis but unchanged ultrastructure of the fibrin meshwork. Liquefaction rate and lesion dimensions produced with the same histotripsy protocols correlated with the increase in the degree of retraction and were lower in retracted samples versus freshly clotted samples. More than 80% of residual fibrin fragments after histotripsy treatment were shorter than 150 µm; the maximum length was 208 µm, allowing for unobstructed aspiration of the lysate with most clinically used needles. CONCLUSION The results indicate that hematoma susceptibility to histotripsy liquefaction is not entirely determined by its stiffness, and correlates with the retraction degree.
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Affiliation(s)
| | - Pavel B Rosnitskiy
- Division of Gastroenterology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - Sergey A Tsysar
- Physics Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Tatiana D Khokhlova
- Division of Gastroenterology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - Maria M Karzova
- Physics Faculty, Lomonosov Moscow State University, Moscow, Russia
| | | | | | - Alexey V Kadrev
- Department of Urology and Andrology, Medical Research and Educational Center, Lomonosov Moscow State University, Moscow, Russia; Diagnostic Ultrasound Division, Russian Medical Academy of Continuous Professional Education, Moscow, Russia
| | - Sergey V Buravkov
- Faculty of Fundamental Medicine, Lomonosov Moscow State University, Moscow, Russia
| | - Pavel E Trakhtman
- National Medical Research Center for Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | - Nicolay N Starostin
- National Medical Research Center for Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | - Oleg A Sapozhnikov
- Physics Faculty, Lomonosov Moscow State University, Moscow, Russia; Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Vera A Khokhlova
- Physics Faculty, Lomonosov Moscow State University, Moscow, Russia; Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
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Verma Y, Perera Molligoda Arachchige AS. Advances in Tumor Management: Harnessing the Potential of Histotripsy. Radiol Imaging Cancer 2024; 6:e230159. [PMID: 38639585 PMCID: PMC11148838 DOI: 10.1148/rycan.230159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 02/22/2024] [Accepted: 03/01/2024] [Indexed: 04/20/2024]
Abstract
Tissue ablation techniques have long been used in clinical settings to treat various oncologic diseases. However, many of these techniques are invasive and can cause substantial adverse effects. Histotripsy is a noninvasive, nonionizing, nonthermal tissue ablation technique that has the potential to replace surgical interventions in various clinical settings. Histotripsy works by delivering high-intensity focused ultrasound waves to target tissue. These waves create cavitation bubbles within tissues that rapidly expand and collapse, thereby mechanically fractionating the tissue into acellular debris that is subsequently absorbed by the body's immune system. Preclinical and clinical studies have demonstrated the efficacy of histotripsy in treating a range of diseases, including liver, pancreatic, renal, and prostate tumors. Safety outcomes of histotripsy have been generally favorable, with minimal adverse effects reported. However, further studies are needed to optimize the technique and understand its long-term effects. This review aims to discuss the importance of histotripsy as a noninvasive tissue ablation technique, the preclinical and clinical literature on histotripsy and its safety, and the potential applications of histotripsy in clinical practice. Keywords: Tumor Microenvironment, Ultrasound-High-Intensity Focused (HIFU), Ablation Techniques, Abdomen/GI, Genital/Reproductive, Nonthermal Tissue Ablation, Histotripsy, Clinical Trials, Preclinical Applications, Focused Ultrasound © RSNA, 2024.
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Maxwell AD, Vlaisavljevich E. Cavitation-induced pressure saturation: a mechanism governing bubble nucleation density in histotripsy. Phys Med Biol 2024; 69:10.1088/1361-6560/ad3721. [PMID: 38518377 PMCID: PMC11212395 DOI: 10.1088/1361-6560/ad3721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 03/22/2024] [Indexed: 03/24/2024]
Abstract
Objective.Histotripsy is a noninvasive focused ultrasound therapy that mechanically disintegrates tissue by acoustic cavitation clouds. In this study, we investigate a mechanism limiting the density of bubbles that can nucleate during a histotripsy pulse. In this mechanism, the pressure generated by the initial bubble expansion effectively negates the incident pressure in the vicinity of the bubble. From this effect, the immediately adjacent tissue is prevented from experiencing the transient tension to nucleate bubbles. Approach.A Keller-Miksis-type single-bubble model was employed to evaluate the dependency of this effect on ultrasound pressure amplitude and frequency, viscoelastic medium properties, bubble nucleus size, and transducer geometric focusing. This model was further combined with a spatial propagation model to predict the peak negative pressure field as a function of position from a cavitating bubble.Main results. The single-bubble model showed the peak negative pressure near the bubble surface is limited to the inertial cavitation threshold. The predicted bubble density increased with increasing frequency, tissue viscosity, and transducer focusing angle. The simulated results were consistent with the trends observed experimentally in prior studies, including changes in density with ultrasound frequency and transducerF-number.Significance.The efficacy of the therapy is dependent on several factors, including the density of bubbles nucleated within the cavitation cloud formed at the focus. These results provide insight into controlling the density of nucleated bubbles during histotripsy and the therapeutic efficacy.
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Affiliation(s)
- Adam D Maxwell
- Department of Urology, University of Washington School of Medicine, Seattle, WA, 98195, United States of America
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24060, United States of America
| | - Eli Vlaisavljevich
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24060, United States of America
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Verma Y, Perera Molligoda Arachchige AS. Revolutionizing brain interventions: the multifaceted potential of histotripsy. Neurosurg Rev 2024; 47:124. [PMID: 38509320 DOI: 10.1007/s10143-024-02353-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 02/26/2024] [Accepted: 03/12/2024] [Indexed: 03/22/2024]
Abstract
Histotripsy, a non-thermal ultrasound technique, holds significant promise in various applications within the realm of brain interventions. While its use for treating brain tumors is somewhat limited, focused ultrasound technology has been extensively investigated for a wide range of purposes within the brain, including disrupting the blood-brain barrier, supporting immunotherapy, addressing conditions like essential tremor, Parkinson's disease, Alzheimer's disease, epilepsy, and neuropathic pain. Research findings indicate that histotripsy can reduce tumor cells with fewer pulses, minimizing the risk of bleeding and cellular injury. The use of MRI sequences such as T2 and T2* enhances the evaluation of the effects of histotripsy treatment, facilitating non-invasive assessment of treated areas. Furthermore, histotripsy displays promise in creating precise brain lesions with minimal edema and inflammation, particularly in porcine models, suggesting considerable progress in the treatment of brain lesions. Moreover, studies confirm its feasibility, safety, and effectiveness in treating intracerebral hemorrhage by safely liquefying clots without causing significant harm to surrounding brain tissue., opening exciting possibilities for clinical applications. The development of transcranial MR-guided focused ultrasound systems based on histotripsy represents a significant breakthrough in overcoming the limitations associated with thermal ablation techniques. Histotripsy's ability to efficiently liquefy clots, minimize skull heating, and target shallow lesions near the skull establishes it as a promising alternative for various brain treatments. In conclusion, histotripsy offers diverse potential in the field of brain interventions, encompassing applications ranging from tumor treatment to the management of intracerebral hemorrhage. While challenges such as accurate monitoring and differentiation of treatment effects persist, ongoing research efforts and technological advancements continue to expand the role of histotripsy in both neurology and neurosurgery.
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Affiliation(s)
- Yash Verma
- Norfolk and Norwich University Hospital, Norwich, UK
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12
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Gong L, Wright AR, Hynynen K, Goertz DE. Inducing cavitation within hollow cylindrical radially polarized transducers for intravascular applications. ULTRASONICS 2024; 138:107223. [PMID: 38553135 DOI: 10.1016/j.ultras.2023.107223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 10/31/2023] [Accepted: 12/12/2023] [Indexed: 04/02/2024]
Abstract
Thrombotic occlusions of large blood vessels are increasingly treated with catheter based mechanical approaches, one of the most prominent being to employ aspiration to extract clots through a hollow catheter lumen. A central technical challenge for aspiration catheters is to achieve sufficient suction force to overcome the resistance of clot material entering into the distal tip. In this study, we examine the feasibility of inducing cavitation within hollow cylindrical transducers with a view to ultimately using them to degrade the mechanical integrity of thrombus within the tip of an aspiration catheter. Hollow cylindrical radially polarized PZT transducers with 3.3/2.5 mm outer/inner diameters were assessed. Finite element simulations and hydrophone experiments were used to investigate the pressure field distribution as a function of element length and resonant mode (thickness, length). Operating in thickness mode (∼5 MHz) was found to be associated with the highest internal pressures, estimated to exceed 23 MPa. Cavitation was demonstrated to be achievable within the transducer under degassed water (10 %) conditions using hydrophone detection and high-frequency ultrasound imaging (40 MHz). Cavitation clouds occupied a substantial portion of the transducer lumen, in a manner that was dependent on the pulsing scheme employed (10 and 100 μs pulse lengths; 1.1, 11, and 110 ms pulse intervals). Collectively the results support the feasibility of achieving cavitation within a transducer compatible with mounting in the tip of an aspiration format catheter.
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Affiliation(s)
- Li Gong
- Department of Medical Biophysics, University of Toronto, Canada; Physical Sciences Platform, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada.
| | - Alex R Wright
- Physical Sciences Platform, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Kullervo Hynynen
- Department of Medical Biophysics, University of Toronto, Canada; Physical Sciences Platform, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada
| | - David E Goertz
- Department of Medical Biophysics, University of Toronto, Canada; Physical Sciences Platform, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada
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Worlikar T, Hall T, Zhang M, Mendiratta-Lala M, Green M, Cho CS, Xu Z. Insights from in vivo preclinical cancer studies with histotripsy. Int J Hyperthermia 2024; 41:2297650. [PMID: 38214171 PMCID: PMC11102041 DOI: 10.1080/02656736.2023.2297650] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 12/16/2023] [Indexed: 01/13/2024] Open
Abstract
Histotripsy is the first noninvasive, non-ionizing, and non-thermal ablation technique that mechanically fractionates target tissue into acellular homogenate via controlled acoustic cavitation. Histotripsy has been evaluated for various preclinical applications requiring noninvasive tissue removal including cancer, brain surgery, blood clot and hematoma liquefaction, and correction of neonatal congenital heart defects. Promising preclinical results including local tumor suppression, improved survival outcomes, local and systemic anti-tumor immune responses, and histotripsy-induced abscopal effects have been reported in various animal tumor models. Histotripsy is also being investigated in veterinary patients with spontaneously arising tumors. Research is underway to combine histotripsy with immunotherapy and chemotherapy to improve therapeutic outcomes. In addition to preclinical cancer research, human clinical trials are ongoing for the treatment of liver tumors and renal tumors. Histotripsy has been recently approved by the FDA for noninvasive treatment of liver tumors. This review highlights key learnings from in vivo shock-scattering histotripsy, intrinsic threshold histotripsy, and boiling histotripsy cancer studies treating cancers of different anatomic locations and discusses the major considerations in planning in vivo histotripsy studies regarding instrumentation, tumor model, study design, treatment dose, and post-treatment tumor monitoring.
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Affiliation(s)
- Tejaswi Worlikar
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Timothy Hall
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Man Zhang
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | | | - Michael Green
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, USA
- Radiation Oncology, Ann Arbor VA Healthcare, Ann Arbor, Michigan, USA
| | - Clifford S. Cho
- Department of Surgery, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Research Service, Ann Arbor VA Healthcare, Ann Arbor, Michigan, USA
| | - Zhen Xu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
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Simon A, Edsall C, Maxwell A, Vlaisavljevich E. Effects of pulse repetition frequency on bubble cloud characteristics and ablation in single-cycle histotripsy. Phys Med Biol 2024; 69:025018. [PMID: 38041873 DOI: 10.1088/1361-6560/ad11a1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 12/01/2023] [Indexed: 12/04/2023]
Abstract
Objective. Histotripsy is a cavitation-based ultrasound ablation method in development for multiple clinical applications. This work investigates the effects of pulse repetition frequency (PRF) on bubble cloud characteristics and ablative capabilities for histotripsy using single-cycle pulsing methods.Approach.Bubble clouds produced by a 500 kHz histotripsy system at PRFs from 0.1 to 1000 Hz were visualized using high-speed optical imaging in 1% agarose tissue phantoms at peak negative pressures,p-, of 2-36 MPa.Main results.Results showed a decrease in the cavitation cloud threshold with increasing PRF, ranging from 26.7 ± 0.5 MPa at 0.1 Hz to 15.0 ± 1.9 MPa at 1000 Hz. Bubble cloud analysis showed cavitation clouds generated at low PRFs (0.1-1 Hz) were characterized by consistently dense bubble clouds (41.7 ± 2.8 bubbles mm-2at 0.1 Hz), that closely matched regions of the focus above the histotripsy intrinsic threshold. Bubble clouds formed at higher PRFs measured lower cloud densities (23.1 ± 4.0 bubbles mm-2at 1000 Hz), with the lowest density measured for 10 Hz (8.8 ± 4.1 bubbles mm-2). Furthermore, higher PRFs showed increased pulse-to-pulse correlation, characteristic of cavitation memory effects; however, bubble clouds still filled the entire volume of the focus due to their initial density and enhanced bubble expansion from the restimulation of residual nuclei at the higher PRFs. Histotripsy ablation assessed through lesion analysis in red blood cell (RBC) phantoms showed higher PRFs generated lesions with lower adherence to the initial focal region compared to low PRF ablations; however, no trend of decreasing ablation efficiency with PRF was observed, with similar efficiencies observed for all the PRFs tested in this study.Significance.Notably, this result is different than what has previously been shown for shock-scattering histotripsy, which has shown decreased ablation efficiencies at higher PRFs. Overall, this study demonstrates the essential effects of PRF on single-cycle histotripsy procedures that should be considered to help guide future histotripsy pulsing strategies.
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Affiliation(s)
- Alex Simon
- Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, United States of America
| | - Connor Edsall
- Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, United States of America
| | - Adam Maxwell
- Department of Urology, University of Washington, Seattle, WA, United States of America
| | - Eli Vlaisavljevich
- Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, United States of America
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15
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Edsall C, Fergusson A, Davis RM, Meyer CH, Allen SP, Vlaisavljevich E. Probability of Cavitation in a Custom Iron-Based Coupling Medium for Transcranial Magnetic Resonance-Guided Focused Ultrasound Procedures. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:2519-2526. [PMID: 37730478 PMCID: PMC10591864 DOI: 10.1016/j.ultrasmedbio.2023.08.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 06/13/2023] [Accepted: 08/16/2023] [Indexed: 09/22/2023]
Abstract
OBJECTIVE A coupling bath of circulating, chilled, degassed water is essential to safe and precise acoustic transmittance during transcranial magnetic resonance-guided focused ultrasound (tMRgFUS) procedures, but the circulating water impairs the critical real-time magnetic resonance imaging (MRI). An iron-based coupling medium (IBCM) using iron oxide nanoparticles previously developed by our group increased the relaxivity of the coupling bath such that it appears to be invisible on MRI compared with degassed water. However, the nanoparticles also reduced the pressure threshold for cavitation. To address this concern for prefocal cavitation, our group recently developed an IBCM of electrosterically stabilized and aggregation-resistant poly(methacrylic acid)-coated iron oxide nanoparticles (PMAA-FeOX) with a similar capability to reduce the MR signal of degassed water. This study examines the effect of the PMAA-FeOX IBCM on the cavitation threshold. METHODS Increasing concentrations of PMAA-FeOX nanoparticles in degassed, deionized water were placed at the focus of two different transducers to assess low and high duty-cycle pulsing parameters which are representative of two modes of focused ultrasound being investigated for tMRgFUS. Passive cavitation detection and high-speed optical imaging were used to measure cavitation threshold pressures. RESULTS The mean cavitation threshold was determined in both cases to be indistinguishable from the degassed water control, between 6-8 MPa for high duty-cycle pulsing (CW) and between 25.5-26.5 MPa for very low duty-cycle pulsing. CONCLUSION The findings of this study indicate that an IBCM of PMAA-FeOX nanoparticles is a possible solution to reducing MRI interference from the coupling bath without increasing the risk of prefocal cavitation.
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Affiliation(s)
- Connor Edsall
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Austin Fergusson
- Translational Biology, Medicine, and Health Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Richey M Davis
- Department of Chemical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Craig H Meyer
- Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Steven P Allen
- Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT, USA
| | - Eli Vlaisavljevich
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; ICTAS Center for Engineered Health, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
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Ambekar PA, Wang YN, Khokhlova T, Bruce M, Leotta DF, Totten S, Maxwell AD, Chan K, Liles WC, Dellinger EP, Monsky W, Adedipe AA, Matula TJ. Comparative Study of Histotripsy Pulse Parameters Used to Inactivate Escherichia coli in Suspension. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:2451-2458. [PMID: 37718123 PMCID: PMC10591824 DOI: 10.1016/j.ultrasmedbio.2023.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 06/07/2023] [Accepted: 08/05/2023] [Indexed: 09/19/2023]
Abstract
OBJECTIVE Bacterial loads can be effectively reduced using cavitation-mediated focused ultrasound, or histotripsy. In this study, gram-negative bacteria (Escherichia coli) in suspension were used as model bacteria to evaluate the effectiveness of two regimens of histotripsy treatments: cavitation histotripsy (CH) and boiling histotripsy (BH). METHODS Ten-milliliter volumes of Escherichia coli were treated at different negative focal pressure amplitudes and over time periods up to 40 min. Cavitation activity was characterized with coaxial passive cavitation detection (PCD) and synchronized plane wave B-mode imaging. RESULTS CH treatments exhibited a threshold behavior that was consistent with PCD metrics of cavitation. Above the threshold, bacterial inactivation followed a monotonically increasing log-linear relationship that indicated an exponential inactivation rate. BH exhibited no threshold, but instead followed a different monotonically increasing inactivation rate. Inactivation rates were larger for BH at or below the CH threshold, and larger for CH substantially above the threshold. CH studies performed at different pulse lengths at the same duty cycle had similar inactivation rates, suggesting that at any given pressure amplitude, the "on time" was the most important variable for inactivating E. coli. The maximum inactivation was produced by CH at the highest pressure amplitudes used, leading to a log reduction >4.2 for a 40 min treatment. CONCLUSION The results of this study suggest that both CH and BH can be used to inactivate E. coli in suspension, with the optimal regimen depending on the attainable peak negative focal pressure at the target.
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Affiliation(s)
- Pratik A Ambekar
- Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Yak-Nam Wang
- Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Tatiana Khokhlova
- Division of Gastroenterology, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Matthew Bruce
- Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Daniel F Leotta
- Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Stephanie Totten
- Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Adam D Maxwell
- Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Keith Chan
- Vantage Radiology and Diagnostic Services, Renton, WA, USA
| | - W Conrad Liles
- Department of Medicine, University of Washington, Seattle, WA, USA; Sepsis Center of Research Excellence-UW (SCORE-UW), University of Washington, Seattle, WA, USA
| | | | - Wayne Monsky
- Department of Radiology, University of Washington, Seattle, WA, USA
| | - Adeyinka A Adedipe
- Department of Emergency Medicine, University of Washington, Seattle, WA, USA
| | - Thomas J Matula
- Applied Physics Laboratory, University of Washington, Seattle, WA, USA.
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Couillard AB, Zlevor AM, Ziemlewicz TJ, Kisting MA, Knott E, Rossebo AE, White J, Lubner MG, Gettle LM, Hinshaw JL, Mao L, Stoffregen W, Swietlik JF, Knavel-Koepsel E, Stratchko L, Abel EJ, Xu Z, Lee FT, Laeseke PF. A Comparison of Histotripsy and Percutaneous Cryoablation in a Chronic Healthy Swine Kidney Model. J Vasc Interv Radiol 2023; 34:1986-1996. [PMID: 37481064 DOI: 10.1016/j.jvir.2023.07.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 06/27/2023] [Accepted: 07/13/2023] [Indexed: 07/24/2023] Open
Abstract
PURPOSE To compare the safety and efficacy of histotripsy with cryoablation in a chronic human-scale normal porcine kidney model. MATERIALS AND METHODS Eighteen female domestic swine were divided evenly into histotripsy and cryoablation treatment arms. A planned 2-3 cm diameter treatment was performed under ultrasound (histotripsy) or ultrasound and computed tomography (CT) guidance (cryoablation). Contrast-enhanced CT and serum blood analysis were performed immediately postprocedure and on day 7, with either immediate killing (n = 3) or continued survival to day 30 (n = 6), at which time contrast-enhanced CT, serum blood analysis, and necropsy were performed. Animal welfare, treatment zone appearance, procedure-related adverse events, and histopathology of the treatment zones and surrounding tissues were assessed. RESULTS Histotripsy treatment zones (mean ±standard deviation diameters, 2.7 ± 0.12 × 2.4 ± 0.19 × 2.4 ± 0.26 cm; volume, 8.3 ± 1.9 cm3) were larger than cryoablation zones (mean diameters, 2.2 ± 0.19 × 1.9 ± 0.13 × 1.7 ± 0.19 cm; volume, 3.9 ± 0.8 cm3; P < .001). At 30 days, histotripsy and cryoablation treatment zone volumes decreased by 96% and 83% on CT, respectively (P < .001). Perirenal hematomas were present after 8 of 9 (89%) cryoablation (mean volume, 22.2 cm3) and 1 of 9 (11%, P < .001) histotripsy (volume, 0.4 cm3) procedures, with active arterial extravasation in 4 of 9 (44%) cryoablation and no histotripsy animals (P = .206). All 9 histotripsy animals and 5 of 9 (56%) cryoablation animals had collecting system debris (P = .042). Changes in serum creatinine were similar between the groups (P = .321). CONCLUSIONS Other than a higher rate of bleeding after cryoablation, the safety and early efficacy of histotripsy and cryoablation were comparable for creating treatment zones in a chronic normal porcine kidney model.
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Affiliation(s)
| | - Annie M Zlevor
- Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin
| | | | - Meridith A Kisting
- Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Emily Knott
- Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio
| | - Annika E Rossebo
- Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Jim White
- Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Meghan G Lubner
- Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin
| | | | - J Louis Hinshaw
- Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin; Department of Urology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Lu Mao
- Department of Biostatistics, University of Wisconsin-Madison, Madison, Wisconsin
| | | | - John F Swietlik
- Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin
| | | | - Lindsay Stratchko
- Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin
| | - E Jason Abel
- Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin; Department of Urology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Zhen Xu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan
| | - Fred T Lee
- Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin; Department of Urology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Paul F Laeseke
- Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin; Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin.
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18
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Yeats E, Hall TL. Aberration correction in abdominal histotripsy. Int J Hyperthermia 2023; 40:2266594. [PMID: 37813397 PMCID: PMC10637766 DOI: 10.1080/02656736.2023.2266594] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 09/28/2023] [Indexed: 10/11/2023] Open
Abstract
In transabdominal histotripsy, ultrasound pulses are focused on the body to noninvasively destroy soft tissues via cavitation. However, the ability to focus is limited by phase aberration, or decorrelation of the ultrasound pulses due to spatial variation in the speed of sound throughout heterogeneous tissue. Phase aberration shifts, broadens, and weakens the focus, thereby reducing the safety and efficacy of histotripsy therapy. This paper reviews and discusses aberration effects in histotripsy and in related therapeutic ultrasound techniques (e.g., high intensity focused ultrasound), with an emphasis on aberration by soft tissues. Methods for aberration correction are reviewed and can be classified into two groups: model-based methods, which use segmented images of the tissue as input to an acoustic propagation model to predict and compensate phase differences, and signal-based methods, which use a receive-capable therapy array to detect phase differences by sensing acoustic signals backpropagating from the focus. The relative advantages and disadvantages of both groups of methods are discussed. Importantly, model-based methods can correct focal shift, while signal-based methods can restore substantial focal pressure, suggesting that both methods should be combined in a 2-step approach. Aberration correction will be critical to improving histotripsy treatments and expanding the histotripsy treatment envelope to enable non-invasive, non-thermal histotripsy therapy for more patients.
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Affiliation(s)
- Ellen Yeats
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, United States
| | - Timothy L. Hall
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, United States
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Aliabouzar M, Abeid BA, Kripfgans OD, Fowlkes JB, Estrada JB, Fabiilli ML. Real-time spatiotemporal characterization of mechanics and sonoporation of acoustic droplet vaporization in acoustically responsive scaffolds. APPLIED PHYSICS LETTERS 2023; 123:114101. [PMID: 37705893 PMCID: PMC10497320 DOI: 10.1063/5.0159661] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 08/26/2023] [Indexed: 09/15/2023]
Abstract
Phase-shift droplets provide a flexible and dynamic platform for therapeutic and diagnostic applications of ultrasound. The spatiotemporal response of phase-shift droplets to focused ultrasound, via the mechanism termed acoustic droplet vaporization (ADV), can generate a range of bioeffects. Although ADV has been used widely in theranostic applications, ADV-induced bioeffects are understudied. Here, we integrated ultra-high-speed microscopy, confocal microscopy, and focused ultrasound for real-time visualization of ADV-induced mechanics and sonoporation in fibrin-based, tissue-mimicking hydrogels. Three monodispersed phase-shift droplets-containing perfluoropentane (PFP), perfluorohexane (PFH), or perfluorooctane (PFO)-with an average radius of ∼6 μm were studied. Fibroblasts and tracer particles, co-encapsulated within the hydrogel, were used to quantify sonoporation and mechanics resulting from ADV, respectively. The maximum radial expansion, expansion velocity, induced strain, and displacement of tracer particles were significantly higher in fibrin gels containing PFP droplets compared to PFH or PFO. Additionally, cell membrane permeabilization significantly depended on the distance between the droplet and cell (d), decreasing rapidly with increasing d. Significant membrane permeabilization occurred when d was smaller than the maximum radius of expansion. Both ultra-high-speed and confocal images indicate a hyper-local region of influence by an ADV bubble, which correlated inversely with the bulk boiling point of the phase-shift droplets. The findings provide insight into developing optimal approaches for therapeutic applications of ADV.
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Affiliation(s)
| | - Bachir A. Abeid
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | | | | | - Jonathan B. Estrada
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
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Trivedi VV, Wallach EL, Bader KB, Shekhar H. Contrast-Enhanced Imaging of Histotripsy Bubble Clouds Using Chirp-Coded Excitation and Volterra Filtering. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2023; 70:989-998. [PMID: 37379172 DOI: 10.1109/tuffc.2023.3289918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/30/2023]
Abstract
Histotripsy is a focused ultrasound therapy that ablates tissue via bubble cloud activity. Real-time ultrasound image guidance is used to ensure safe and effective treatment. Plane-wave imaging enables tracking of histotripsy bubble clouds at a high frame rate but lacks adequate contrast. Furthermore, bubble cloud hyperechogenicity is reduced in abdominal targets, making the development of contrast-specific sequences for deep-seated targets an active area of research. Chirp-coded subharmonic imaging was reported previously to enhance histotripsy bubble cloud detection by a modest 4-6 dB compared to the conventional sequence. Incorporating additional steps into the signal processing pipeline could enhance bubble cloud detection and tracking. In this study, we evaluated the feasibility of combining chirp-coded subharmonic imaging with Volterra filtering for enhancing bubble cloud detection in vitro. Chirped imaging pulses were used to track bubble clouds generated in scattering phantoms at a 1-kHz frame rate. Fundamental and subharmonic matched filters were applied to the received radio frequency signals, followed by a tuned Volterra filter to extract bubble-specific signatures. For subharmonic imaging, the application of the quadratic Volterra filter improved the contrast-to-tissue ratio from 5.18 ± 1.29 to 10.90 ± 3.76 dB, relative to the application of the subharmonic matched filter. These findings demonstrate the utility of the Volterra filter for histotripsy image guidance.
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21
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Rosnitskiy PB, Tsysar SA, Karzova MM, Buravkov SV, Malkov PG, Danilova NV, Ponomarchuk EM, Sapozhnikov OA, Khokhlova TD, Schade GR, Maxwell AD, Wang YN, Kadrev AV, Chernyaev AL, Okhobotov DA, Kamalov AA, Khokhlova VA. Pilot ex vivo study on non-thermal ablation of human prostate adenocarcinoma tissue using boiling histotripsy. ULTRASONICS 2023; 133:107029. [PMID: 37207594 PMCID: PMC10438901 DOI: 10.1016/j.ultras.2023.107029] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/27/2023] [Accepted: 05/01/2023] [Indexed: 05/21/2023]
Abstract
Focused ultrasound technologies are of growing interest for noninvasive ablation of localized prostate cancer (PCa). Here we present the results of the first case study evaluating the feasibility of non-thermal mechanical ablation of human prostate adenocarcinoma tissue using the boiling histotripsy (BH) method on ex vivo tissue. High intensity focused ultrasound field was generated using a 1.5-MHz custom-made transducer with nominal F#=0.75. A sonication protocol of 734 W acoustic power, 10-ms long BH-pulses, 30 pulses per focal spot, 1 % duty cycle, and 1 mm distance between single foci was tested in an ex vivo human prostate tissue sample containing PCa. The protocol used here has been successfully applied in the previous BH studies for mechanical disintegration of ex vivo prostatic human tissue with benign hyperplasia. BH treatment was monitored using B-mode ultrasound. Post-treatment histologic analysis demonstrated BH produced liquefaction of the targeted tissue volume. BH treated benign prostate parenchyma and PCa had similar tissue fractionation into subcellular fragments. The results of the study demonstrated that PCa tumor tissue can be mechanically ablated using the BH method. Further studies will aim on optimizing protocol parameters to accelerate treatment while maintaining complete destruction of the targeted tissue volume into subcellular debris.
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Affiliation(s)
- P B Rosnitskiy
- Lomonosov Moscow State University, Physics Faculty, Moscow, Russia.
| | - S A Tsysar
- Lomonosov Moscow State University, Physics Faculty, Moscow, Russia
| | - M M Karzova
- Lomonosov Moscow State University, Physics Faculty, Moscow, Russia
| | - S V Buravkov
- Lomonosov Moscow State University, Faculty of Fundamental Medicine, Moscow, Russia
| | - P G Malkov
- Lomonosov Moscow State University, Medical Research and Educational Center, Moscow, Russia
| | - N V Danilova
- Lomonosov Moscow State University, Medical Research and Educational Center, Moscow, Russia
| | - E M Ponomarchuk
- Lomonosov Moscow State University, Physics Faculty, Moscow, Russia
| | - O A Sapozhnikov
- Lomonosov Moscow State University, Physics Faculty, Moscow, Russia; University of Washington, Applied Physics Laboratory, Center for Industrial and Medical Ultrasound, Seattle, WA, USA
| | - T D Khokhlova
- University of Washington School of Medicine, Department of Medicine, Division of Gastroenterology, Seattle, WA, USA
| | - G R Schade
- University of Washington School of Medicine, Department of Urology, Seattle, WA, USA
| | - A D Maxwell
- University of Washington School of Medicine, Department of Urology, Seattle, WA, USA
| | - Y-N Wang
- University of Washington, Applied Physics Laboratory, Center for Industrial and Medical Ultrasound, Seattle, WA, USA
| | - A V Kadrev
- Lomonosov Moscow State University, Medical Research and Educational Center, Moscow, Russia; Russian Medical Academy of Continuous Professional Education, Diagnostic Ultrasound Division, Moscow, Russia
| | - A L Chernyaev
- Pulmonology Scientific Research Institute, Moscow, Russia
| | - D A Okhobotov
- University of Washington, Applied Physics Laboratory, Center for Industrial and Medical Ultrasound, Seattle, WA, USA
| | - A A Kamalov
- University of Washington, Applied Physics Laboratory, Center for Industrial and Medical Ultrasound, Seattle, WA, USA
| | - V A Khokhlova
- Lomonosov Moscow State University, Physics Faculty, Moscow, Russia; University of Washington, Applied Physics Laboratory, Center for Industrial and Medical Ultrasound, Seattle, WA, USA
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22
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Thomas GPL, Khokhlova TD, Sapozhnikov OA, Khokhlova VA. Enhancement of Boiling Histotripsy by Steering the Focus Axially During the Pulse Delivery. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2023; 70:865-875. [PMID: 37318967 PMCID: PMC10671942 DOI: 10.1109/tuffc.2023.3286759] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Boiling histotripsy (BH) is a pulsed high-intensity focused ultrasound (HIFU) method relying on the generation of high-amplitude shocks at the focus, localized enhanced shock-wave heating, and bubble activity driven by shocks to induce tissue liquefaction. BH uses sequences of 1-20 ms long pulses with shock fronts of over 60 MPa amplitude, initiates boiling at the focus of the HIFU transducer within each pulse, and the remainder shocks of the pulse then interact with the boiling vapor cavities. One effect of this interaction is the creation of a prefocal bubble cloud due to reflection of shocks from the initially generated mm-sized cavities: the shocks are inverted when reflected from a pressure-release cavity wall resulting in sufficient negative pressure to reach intrinsic cavitation threshold in front of the cavity. Secondary clouds then form due to shock-wave scattering from the first one. Formation of such prefocal bubble clouds has been known as one of the mechanisms of tissue liquefaction in BH. Here, a methodology is proposed to enlarge the axial dimension of this bubble cloud by steering the HIFU focus toward the transducer after the initiation of boiling until the end of each BH pulse and thus to accelerate treatment. A BH system comprising a 1.5 MHz 256-element phased array connected to a Verasonics V1 system was used. High-speed photography of BH sonications in transparent gels was performed to observe the extension of the bubble cloud resulting from shock reflections and scattering. Volumetric BH lesions were then generated in ex vivo tissue using the proposed approach. Results showed up to almost threefold increase of the tissue ablation rate with axial focus steering during the BH pulse delivery compared to standard BH.
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23
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Kagami S, Kanagawa T. Weakly nonlinear focused ultrasound in viscoelastic media containing multiple bubbles. ULTRASONICS SONOCHEMISTRY 2023; 97:106455. [PMID: 37271029 DOI: 10.1016/j.ultsonch.2023.106455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 05/12/2023] [Accepted: 05/23/2023] [Indexed: 06/06/2023]
Abstract
To facilitate practical medical applications such as cancer treatment utilizing focused ultrasound and bubbles, a mathematical model that can describe the soft viscoelasticity of human body, the nonlinear propagation of focused ultrasound, and the nonlinear oscillations of multiple bubbles is theoretically derived and numerically solved. The Zener viscoelastic model and Keller-Miksis bubble equation, which have been used for analyses of single or few bubbles in viscoelastic liquid, are used to model the liquid containing multiple bubbles. From the theoretical analysis based on the perturbation expansion with the multiple-scales method, the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation, which has been used as a mathematical model of weakly nonlinear propagation in single phase liquid, is extended to viscoelastic liquid containing multiple bubbles. The results show that liquid elasticity decreases the magnitudes of the nonlinearity, dissipation, and dispersion of ultrasound and increases the phase velocity of the ultrasound and linear natural frequency of the bubble oscillation. From the numerical calculation of resultant KZK equation, the spatial distribution of the liquid pressure fluctuation for the focused ultrasound is obtained for cases in which the liquid is water or liver tissue. In addition, frequency analysis is carried out using the fast Fourier transform, and the generation of higher harmonic components is compared for water and liver tissue. The elasticity supresses the generation of higher harmonic components and promotes the remnant of the fundamental frequency components. This indicates that the elasticity of liquid suppresses shock wave formation in practical applications.
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Affiliation(s)
- Shunsuke Kagami
- Department of Engineering Mechanics and Energy, Degree Program of Systems and Information Engineering, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8573, Japan.
| | - Tetsuya Kanagawa
- Department of Engineering Mechanics and Energy, Degree Program of Systems and Information Engineering, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8573, Japan.
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Pahk KJ, Heo J, Joung C, Pahk K. Noninvasive mechanical destruction of liver tissue and tissue decellularisation by pressure-modulated shockwave histotripsy. Front Immunol 2023; 14:1150416. [PMID: 37261363 PMCID: PMC10227506 DOI: 10.3389/fimmu.2023.1150416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 05/04/2023] [Indexed: 06/02/2023] Open
Abstract
Introduction Boiling histotripsy (BH) is a promising High Intensity Focused Ultrasound (HIFU) technique that can be used to mechanically fractionate solid tumours at the HIFU focus noninvasively, promoting tumour immunity. Because of the occurrence of shock scattering phenomenon during BH process, the treatment accuracy of BH is, however, somewhat limited. To induce more localised and selective tissue destruction, the concept of pressure modulation has recently been proposed in our previous in vitro tissue phantom study. The aim of the present study was therefore to investigate whether this newly developed histotripsy approach termed pressure-modulated shockwave histotripsy (PSH) can be used to induce localised mechanical tissue fractionation in in vivo animal model. Methods In the present study, 8 Sprague Dawley rats underwent the PSH treatment and were sacrificed immediately after the exposure for morphological and histological analyses (paraffin embedded liver tissue sections were stained with H&E and MT). Partially exteriorised rat's left lateral liver lobe in vivo was exposed to a 2.0 MHz HIFU transducer with peak positive (P +) and negative (P -) pressures of 89.1 MPa and -14.6 MPa, a pulse length of 5 to 34 ms, a pressure modulation time at 4 ms where P + and P - decreased to 29.9 MPa and - 9.6 MPa, a pulse repetition frequency of 1 Hz, a duty cycle of 1% and number of pulses of 1 to 20. Three lesions were produced on each animal. For comparison, the same exposure condition but no pressure modulation was also employed to create a number of lesions in the liver. Results and Discussion Experimental results showed that a partial mechanical destruction of liver tissue in the form of an oval in the absence of thermal damage was clearly observed at the HIFU focus after the PSH exposure. With a single pulse length of 7 ms, a PSH lesion created in the liver was measured to be a length of 1.04 ± 0.04 mm and a width of 0.87 ± 0.21 mm which was 2.37 times in length (p = 0.027) and 1.35 times in width (p = 0.1295) smaller than a lesion produced by no pressure modulation approach (e.g., BH). It was also observed that the length of a PSH lesion gradually grew towards the opposite direction to the HIFU source along the axial direction with the PSH pulse length, eventually leading to the generation of an elongated lesion in the liver. In addition, our experimental results demonstrated the feasibility of inducing partial decellularisation effect where liver tissue was partially destructed with intact extracellular matrix (i.e., intact fibrillar collagen) with the shortest PSH pulse length. Taken together, these results suggest that PSH could be used to induce a highly localised tissue fractionation with a desired degree of mechanical damage from complete tissue fractionation to tissue decellularisation through controlling the dynamics of boiling bubbles without inducing the shock scattering effect.
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Affiliation(s)
- Ki Joo Pahk
- Department of Biomedical Engineering, Kyung Hee University, Yongin, Republic of Korea
| | - Jeongmin Heo
- Center for Bionics, Biomedical Research Institute, Korea Institute of Science and Technology, Seoul, Republic of Korea
| | - Chanmin Joung
- Graduate School of Biomedical Sciences, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Kisoo Pahk
- Department of Nuclear Medicine, Korea University College of Medicine, Seoul, Republic of Korea
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Koukas E, Papoutsakis A, Gavaises M. Numerical investigation of shock-induced bubble collapse dynamics and fluid-solid interactions during shock-wave lithotripsy. ULTRASONICS SONOCHEMISTRY 2023; 95:106393. [PMID: 37031534 PMCID: PMC10114246 DOI: 10.1016/j.ultsonch.2023.106393] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/14/2023] [Accepted: 03/28/2023] [Indexed: 06/19/2023]
Abstract
In this paper we investigate the bubble collapse dynamics under shock-induced loading near soft and rigid bio-materials, during shock wave lithotripsy. A novel numerical framework was developed, that employs a Diffuse Interface Method (DIM) accounting for the interaction across fluid-solid-gas interfaces. For the resolution of the extended variety of length scales, due to the dynamic and fine interfacial structures, an Adaptive Mesh Refinement (AMR) framework for unstructured grids was incorporated. This multi-material multi-scale approach aims to reduce the numerical diffusion and preserve sharp interfaces. The presented numerical framework is validated for cases of bubble dynamics, under high and low ambient pressure ratios, shock-induced collapses, and wave transmission problems across a fluid-solid interface, against theoretical and numerical results. Three different configurations of shock-induced collapse applications near a kidney stone and soft tissue have been simulated for different stand-off distances and bubble attachment configurations. The obtained results reveal the detailed collapse dynamics, jet formation, solid deformation, rebound, primary and secondary shock wave emissions, and secondary collapse that govern the near-solid collapse and penetration mechanisms. Significant correlations of the problem configuration to the overall collapse mechanisms were found, stemming from the contact angle/attachment of the bubble and from the properties of solid material. In general, bubbles with their center closer to the kidney stone surface produce more violent collapses. For the soft tissue, the bubble movement prior to the collapse is of great importance as new structures can emerge which can trap the liquid jet into induced crevices. Finally, the tissue penetration is examined for these cases and a novel tension-driven tissue injury mechanism is elucidated, emanating from the complex interaction of the bubble/tissue interaction during the secondary collapse phase of an entrapped bubble in an induced crevice with the liquid jet.
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Affiliation(s)
- Evangelos Koukas
- Department of Mechanical Engineering and Aeronautics, School of Mathematics, Computer Science and Engineering, City University of London, Northampton Square, EC1V 0HB London, UK.
| | - Andreas Papoutsakis
- Department of Engineering, School of Physics Engineering and Computer Science (SPECS), University of Hertfordshire, College Lane Campus, AL10 9AB Hatfield, UK
| | - Manolis Gavaises
- Department of Mechanical Engineering and Aeronautics, School of Mathematics, Computer Science and Engineering, City University of London, Northampton Square, EC1V 0HB London, UK
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Yeats E, Lu N, Sukovich JR, Xu Z, Hall TL. Soft Tissue Aberration Correction for Histotripsy Using Acoustic Emissions From Cavitation Cloud Nucleation and Collapse. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:1182-1193. [PMID: 36759271 PMCID: PMC10082475 DOI: 10.1016/j.ultrasmedbio.2023.01.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 12/01/2022] [Accepted: 01/03/2023] [Indexed: 05/11/2023]
Abstract
OBJECTIVE Phase aberration from soft tissue limits the efficacy of histotripsy, a therapeutic ultrasound technique based on acoustic cavitation. Previous work has shown that the acoustic emissions from cavitation can serve as "point sources" for aberration correction (AC). This study compared the efficacy of soft tissue AC for histotripsy using acoustic cavitation emissions (ACE) from bubble cloud nucleation and collapse. METHODS A 750-kHz, receive-capable histotripsy array was pulsed to generate cavitation in ex vivo porcine liver through an intervening abdominal wall. Received ACE signals were used to determine the arrival time differences to the focus and compute corrective delays. Corrections from single pulses and from the median of multiple pulses were tested. DISCUSSION On average, ACE AC obtained 96% ± 3% of the pressure amplitude obtained by hydrophone-based correction (compared with 71% ± 5% without AC). Both nucleation- and collapse-based corrections obtained >96% of the hydrophone-corrected pressure when using medians of ≥10 pulses. When using single-pulse corrections, nucleation obtained a range of 49%-99% of the hydrophone-corrected pressure, while collapse obtained 95%-99%. CONCLUSION The results suggest that (i) ACE AC can recover nearly all pressure amplitude lost owing to soft tissue aberration and that (ii) the collapse signal permits robust AC using a small number of pulses.
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Affiliation(s)
- Ellen Yeats
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.
| | - Ning Lu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Jonathan R Sukovich
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Zhen Xu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Timothy L Hall
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
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Ruger L, Yang E, Gannon J, Sheppard H, Coutermarsh-Ott S, Ziemlewicz TJ, Dervisis N, Allen IC, Daniel GB, Tuohy J, Vlaisavljevich E, Klahn S. Mechanical High-Intensity Focused Ultrasound (Histotripsy) in Dogs With Spontaneously Occurring Soft Tissue Sarcomas. IEEE Trans Biomed Eng 2023; 70:768-779. [PMID: 36006886 PMCID: PMC9969335 DOI: 10.1109/tbme.2022.3201709] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
INTRODUCTION Histotripsy is a non-invasive focused ultrasound therapy that uses controlled acoustic cavitation to mechanically disintegrate tissue. To date, there are no reports investigating histotripsy for the treatment of soft tissue sarcoma (STS). OBJECTIVE This study aimed to investigate the in vivo feasibility of ablating STS with histotripsy and to characterize the impact of partial histotripsy ablation on the acute immunologic response in canine patients with spontaneous STS. METHODS A custom 500 kHz histotripsy system was used to treat ten dogs with naturally occurring STS. Four to six days after histotripsy, tumors were surgically resected. Safety was determined by monitoring vital signs during treatment and post-treatment physical examinations, routine lab work, and owners' reports. Ablation was characterized using radiologic and histopathologic analyses. Systemic immunological impact was evaluated by measuring changes in cytokine concentrations, and tumor microenvironment changes were evaluated by characterizing changes in infiltration with tumor-associated macrophages (TAMs) and tumor-infiltrating lymphocytes (TILs) using multiplex immunohistochemistry and differential gene expression. RESULTS Results showed histotripsy ablation was achievable and well-tolerated in all ten dogs. Immunological results showed histotripsy induced pro-inflammatory changes in the tumor microenvironment. Conclusion & Significance: Overall, this study demonstrates histotripsy's potential as a precise, non-invasive treatment for STS.
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Knott EA, Zlevor AM, Hinshaw JL, Laeseke PF, Longhurst C, Frank J, Bradley CW, Couillard AB, Rossebo AE, Xu Z, Lee FT, Ziemlewicz TJ. A comparison study of microwave ablation vs. histotripsy for focal liver treatments in a swine model. Eur Radiol 2023; 33:1050-1062. [PMID: 36048208 DOI: 10.1007/s00330-022-09112-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 07/06/2022] [Accepted: 08/11/2022] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To compare the acute and chronic safety and treatment effects of non-invasive hepatic histotripsy vs. percutaneous microwave (MW) ablation in a healthy porcine model. METHODS This was a dual-arm study in which each animal (n = 14) received either a single hepatic microwave (n = 6) or histotripsy (n = 6 single treatment; n = 2 double treatment) under ultrasound guidance. The goal was to create 2.5-3.0 cm short-axis treatments in similar locations across modalities. Animals were survived for 1 month with contrast-enhanced CT imaging on days 0, 2, 7, 14, and 28. On day 28, necropsy and histopathology were performed. RESULTS All procedures were well-tolerated. MW ablation zones were longer and more oblong, but equivalent in the short axes to histotripsy zones on immediate post-procedure CT (p < 0.001 and p = 0.45, respectively). Overall, MW volumes were larger (21.4 cm3 vs. 13.4 cm3; p = 0.001) and histotripsy treatment zones were more spherical (p = 0.007). Histotripsy zones were close to the prescribed size (p < 0.001). Over the study period, histotripsy treatment zones decreased in volume while microwave ablation zones slightly increased (-83% vs. +17%, p = 0.001). There were several imaging-only findings: Branch portal vein thrombus with both histotripsy (7/8) and MW (6/6), hematoma in 2/6 MW only, and a gallbladder injury in 1/6 MW animals. The ablation zones demonstrated complete cellular destruction for both modalities. CONCLUSION Histotripsy was associated with more spherical treatments, fewer biliary complications, and greater treatment zone involution. Hepatic MW and histotripsy treatment in a normal porcine model appear at least equally effective for creating treatment zones with a similar safety profile. KEY POINTS • Microwave ablation and histotripsy for liver treatment in a healthy porcine model yield equivalent procedural tolerance and cellular destruction. • Histotripsy was associated with more spherical treatments, fewer biliary complications, and greater treatment zone involution over the 28-day follow-up period. • These findings confirm the safety and efficacy of hepatic histotripsy and support the pursuit of clinical trials to further evaluate the translatability of these results.
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Affiliation(s)
- Emily A Knott
- The Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA
| | - Annie M Zlevor
- Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Ave, Madison, WI, 53792, USA
| | - J Louis Hinshaw
- Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Ave, Madison, WI, 53792, USA
- Department of Urology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Paul F Laeseke
- Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Ave, Madison, WI, 53792, USA
| | - Colin Longhurst
- Biostatistics and Medical Informatics, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Jenifer Frank
- College of Agriculture and Life Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Charles W Bradley
- Department of Pathobiology, University of Pennsylvania: School of Veterinary Medicine, Philadelphia, PA, USA
| | - Allison B Couillard
- Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Ave, Madison, WI, 53792, USA
| | - Annika E Rossebo
- Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Ave, Madison, WI, 53792, USA
| | - Zhen Xu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Fred T Lee
- Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Ave, Madison, WI, 53792, USA
- Department of Urology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
- College of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Timothy J Ziemlewicz
- Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Ave, Madison, WI, 53792, USA.
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Wagner MG, Periyasamy S, Kutlu AZ, Pieper AA, Swietlik JF, Ziemlewicz TJ, Hall TL, Xu Z, Speidel MA, Jr FTL, Laeseke PF. An X-Ray C-Arm Guided Automatic Targeting System for Histotripsy. IEEE Trans Biomed Eng 2023; 70:592-602. [PMID: 35984807 PMCID: PMC9929026 DOI: 10.1109/tbme.2022.3198600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Histotripsy is an emerging noninvasive, nonionizing and nonthermal focal cancer therapy that is highly precise and can create a treatment zone of virtually any size and shape. Current histotripsy systems rely on ultrasound imaging to target lesions. However, deep or isoechoic targets obstructed by bowel gas or bone can often not be treated safely using ultrasound imaging alone. This work presents an alternative x-ray C-arm based targeting approach and a fully automated robotic targeting system. METHODS The approach uses conventional cone beam CT (CBCT) images to localize the target lesion and 2D fluoroscopy to determine the 3D position and orientation of the histotripsy transducer relative to the C-arm. The proposed pose estimation uses a digital model and deep learning-based feature segmentation to estimate the transducer focal point relative to the CBCT coordinate system. Additionally, the integrated robotic arm was calibrated to the C-arm by estimating the transducer pose for four preprogrammed transducer orientations and positions. The calibrated system can then automatically position the transducer such that the focal point aligns with any target selected in a CBCT image. RESULTS The accuracy of the proposed targeting approach was evaluated in phantom studies, where the selected target location was compared to the center of the spherical ablation zones in post-treatment CBCTs. The mean and standard deviation of the Euclidean distance was 1.4 ±0.5 mm. The mean absolute error of the predicted treatment radius was 0.5 ±0.5 mm. CONCLUSION CBCT-based histotripsy targeting enables accurate and fully automated treatment without ultrasound guidance. SIGNIFICANCE The proposed approach could considerably decrease operator dependency and enable treatment of tumors not visible under ultrasound.
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Khokhlova VA, Rosnitskiy PB, Tsysar SA, Buravkov SV, Ponomarchuk EM, Sapozhnikov OA, Karzova MM, Khokhlova TD, Maxwell AD, Wang YN, Kadrev AV, Chernyaev AL, Chernikov VP, Okhobotov DA, Kamalov AA, Schade GR. Initial Assessment of Boiling Histotripsy for Mechanical Ablation of Ex Vivo Human Prostate Tissue. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:62-71. [PMID: 36207225 PMCID: PMC9712256 DOI: 10.1016/j.ultrasmedbio.2022.07.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 07/27/2022] [Accepted: 07/31/2022] [Indexed: 05/16/2023]
Abstract
Boiling histotripsy (BH) is a focused ultrasound technology that uses millisecond-long pulses with shock fronts to induce mechanical tissue ablation. The pulsing scheme and mechanisms of BH differ from those of cavitation cloud histotripsy, which was previously developed for benign prostatic hyperplasia. The goal of the work described here was to evaluate the feasibility of using BH to ablate fresh ex vivo human prostate tissue as a proof of principle for developing BH for prostate applications. Fresh human prostate samples (N = 24) were obtained via rapid autopsy (<24 h after death, institutional review board exempt). Samples were analyzed using shear wave elastography to ensure that mechanical properties of autopsy tissue were clinically representative. Samples were exposed to BH using 10- or 1-ms pulses with 1% duty cycle under real-time B-mode and Doppler imaging. Volumetric lesions were created by sonicating 1-4 rectangular planes spaced 1 mm apart, containing a grid of foci spaced 1-2 mm apart. Tissue then was evaluated grossly and histologically, and the lesion content was analyzed using transmission electron microscopy and scanning electron microscopy. Observed shear wave elastography characterization of ex vivo prostate tissue (37.9 ± 22.2 kPa) was within the typical range observed clinically. During BH, hyperechoic regions were visualized at the focus on B-mode, and BH-induced bubbles were also detected using power Doppler. As treatment progressed, hypoechoic regions of tissue appeared, suggesting successful tissue fractionation. BH treatment was twofold faster using shorter pulses (1 ms vs. 10 ms). Histological analysis revealed lesions containing completely homogenized cell debris, consistent with histotripsy-induced mechanical ablation. It was therefore determined that BH is feasible in fresh ex vivo human prostate tissue producing desired mechanical ablation. The study supports further work aimed at translating BH technology as a clinical option for prostate ablation.
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Affiliation(s)
- Vera A. Khokhlova
- University of Washington, Applied Physics Laboratory, Center for Industrial and Medical Ultrasound, Seattle, WA
- Lomonosov Moscow State University, Physics Faculty, Moscow, Russia
| | | | - Sergey A. Tsysar
- Lomonosov Moscow State University, Physics Faculty, Moscow, Russia
| | - Sergey V. Buravkov
- Lomonosov Moscow State University, Faculty of Fundamental Medicine, Laboratory of Cell Image Analysis, Moscow, Russia
- Research Institute of Human Morphology, Moscow, Russia
| | | | - Oleg A. Sapozhnikov
- University of Washington, Applied Physics Laboratory, Center for Industrial and Medical Ultrasound, Seattle, WA
- Lomonosov Moscow State University, Physics Faculty, Moscow, Russia
| | - Maria M. Karzova
- Lomonosov Moscow State University, Physics Faculty, Moscow, Russia
| | - Tatiana D. Khokhlova
- University of Washington School of Medicine, Department of Medicine Division of Gastroenterology, Seattle, WA
| | - Adam D. Maxwell
- University of Washington School of Medicine, Department of Urology, Seattle, WA
| | - Yak-Nam Wang
- University of Washington, Applied Physics Laboratory, Center for Industrial and Medical Ultrasound, Seattle, WA
| | - Alexey V. Kadrev
- Lomonosov Moscow State University, Medical Research and Educational Center, Department of Urology and Andrology, Moscow, Russia
- Russian Medical Academy of Continuous Professional Education, Diagnostic Ultrasound Division, Moscow, Russia
| | - Andrey L. Chernyaev
- Research Institute of Human Morphology, Moscow, Russia
- Pulmonology Scientific Research Institute, Moscow, Russia
| | | | - Dmitriy A. Okhobotov
- Lomonosov Moscow State University, Medical Research and Educational Center, Department of Urology and Andrology, Moscow, Russia
| | - Armais A. Kamalov
- Lomonosov Moscow State University, Medical Research and Educational Center, Department of Urology and Andrology, Moscow, Russia
| | - George R. Schade
- University of Washington School of Medicine, Department of Urology, Seattle, WA
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Williams RP, Simon JC, Khokhlova VA, Sapozhnikov OA, Khokhlova TD. The histotripsy spectrum: differences and similarities in techniques and instrumentation. Int J Hyperthermia 2023; 40:2233720. [PMID: 37460101 PMCID: PMC10479943 DOI: 10.1080/02656736.2023.2233720] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/15/2023] [Accepted: 07/02/2023] [Indexed: 07/20/2023] Open
Abstract
Since its inception about two decades ago, histotripsy - a non-thermal mechanical tissue ablation technique - has evolved into a spectrum of methods, each with distinct potentiating physical mechanisms: intrinsic threshold histotripsy, shock-scattering histotripsy, hybrid histotripsy, and boiling histotripsy. All methods utilize short, high-amplitude pulses of focused ultrasound delivered at a low duty cycle, and all involve excitation of violent bubble activity and acoustic streaming at the focus to fractionate tissue down to the subcellular level. The main differences are in pulse duration, which spans microseconds to milliseconds, and ultrasound waveform shape and corresponding peak acoustic pressures required to achieve the desired type of bubble activity. In addition, most types of histotripsy rely on the presence of high-amplitude shocks that develop in the pressure profile at the focus due to nonlinear propagation effects. Those requirements, in turn, dictate aspects of the instrument design, both in terms of driving electronics, transducer dimensions and intensity limitations at surface, shape (primarily, the F-number) and frequency. The combination of the optimized instrumentation and the bio-effects from bubble activity and streaming on different tissues, lead to target clinical applications for each histotripsy method. Here, the differences and similarities in the physical mechanisms and resulting bioeffects of each method are reviewed and tied to optimal instrumentation and clinical applications.
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Affiliation(s)
- Randall P Williams
- Division of Gastroenterology, Department of Medicine, University of Washington, Seattle, WA, USA
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Julianna C Simon
- Graduate Program in Acoustics, The Pennsylvania State University, University Park, PA, USA
| | - Vera A Khokhlova
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
- Department of Acoustics, Physics Faculty, Moscow State University, Moscow, Russia
| | - Oleg A Sapozhnikov
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
- Department of Acoustics, Physics Faculty, Moscow State University, Moscow, Russia
| | - Tatiana D Khokhlova
- Division of Gastroenterology, Department of Medicine, University of Washington, Seattle, WA, USA
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
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Haskell SC, Lu N, Stocker GE, Xu Z, Sukovich JR. Monitoring cavitation dynamics evolution in tissue mimicking hydrogels for repeated exposures via acoustic cavitation emissions. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 153:237. [PMID: 36732269 PMCID: PMC10162839 DOI: 10.1121/10.0016849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 12/15/2022] [Accepted: 12/21/2022] [Indexed: 05/07/2023]
Abstract
A 700 kHz histotripsy array is used to generate repeated cavitation events in agarose, gelatin, and polyacrylamide hydrogels. High-speed optical imaging, a broadband hydrophone, and the narrow-band receive elements of the histotripsy array are used to capture bubble dynamics and acoustic cavitation emissions. Bubble radii, lifespan, shockwave amplitudes are noted to be measured in close agreement between the different observation methods. These features also decrease with increasing hydrogel stiffness for all of the tested materials. However, the evolutions of these properties during the repeated irradiations vary significantly across the different material subjects. Bubble maximum radius initially increases, then plateaus, and finally decreases in agarose, but remains constant across exposures in gelatin and polyacrylamide. The bubble lifespan increases monotonically in agarose and gelatin but decreases in polyacrylamide. Collapse shockwave amplitudes were measured to have different-shaped evolutions between all three of the tested materials. Bubble maximum radii, lifespans, and collapse shockwave amplitudes were observed to express evolutions that are dependent on the structure and stiffness of the nucleation medium.
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Affiliation(s)
- Scott C Haskell
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48105, USA
| | - Ning Lu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48105, USA
| | - Greyson E Stocker
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48105, USA
| | - Zhen Xu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48105, USA
| | - Jonathan R Sukovich
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48105, USA
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A Multi-centre, Single Arm, Non-randomized, Prospective European Trial to Evaluate the Safety and Efficacy of the HistoSonics System in the Treatment of Primary and Metastatic Liver Cancers (#HOPE4LIVER). Cardiovasc Intervent Radiol 2023; 46:259-267. [PMID: 36380155 PMCID: PMC9892119 DOI: 10.1007/s00270-022-03309-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 10/20/2022] [Indexed: 11/16/2022]
Abstract
PURPOSE Image-guided thermal ablation are established treatment options for non-surgical patients with primary and metastatic liver cancers. However, there are limitations with nonuniformity of cancer tissue destruction, heat sink effect and the risk of thermal ablative injury. The current non-thermal ablative techniques have high risk of local recurrence and are not widely adopted. Histotripsy is a treatment technology that destroys targeted tissue under ultrasound visualization via mechanical destruction through the precise application of acoustic cavitation and can offer the potential of non-invasive, non-thermal and non-ionizing radiation cancer treatment. The aim of this multi-centre non-randomized phase I/II trial is to assess the initial safety and efficacy of the prototype investigational 'System' in the treatment of primary and metastatic liver cancers. METHODS/DESIGN All non-surgical patients with primary/metastatic liver cancers having had previous liver directed therapy, radiation therapy or image-guided ablation may be offered image-guided Histotripsy as per trial protocol. The co-primary endpoints are technical success and procedural safety. Technical success is determined, at ≤ 36 h post procedure, by evaluating the histotripsy treatment size and coverage. The procedural safety is defined by procedure related major complications, defined as Common Terminology Criteria for Adverse Events (CTCAE version 5) grade 3 or higher toxicities, up to 30 days post procedure. This phase I/II trial has intended to recruit up to 45 patients to show safety and efficacy of image-guided histotripsy in liver cancers. TRAIL REGISTRATION Clinicaltrials.gov identifier-NCT04573881; NIHR CRN CPMS-ID 47572.
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Imran KM, Ganguly A, Paul T, Powar M, Vlaisavljevich E, Cho CS, Allen IC. Magic bubbles: utilizing histotripsy to modulate the tumor microenvironment and improve systemic anti-tumor immune responses. Int J Hyperthermia 2023; 40:2244206. [PMID: 37580047 PMCID: PMC10430775 DOI: 10.1080/02656736.2023.2244206] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 07/28/2023] [Accepted: 07/29/2023] [Indexed: 08/16/2023] Open
Abstract
Focused Ultrasound (FUS) is emerging as a promising primary and adjunct therapy for the treatment of cancer. This includes histotripsy, which is a noninvasive, non-ionizing, non-thermal ultrasound guided ablation modality. As histotripsy has progressed from bench-to-bedside, it has become evident that this therapy has benefits beyond local tumor ablation. Specifically, histotripsy has the potential to shift the local tumor microenvironment from immunologically 'cold' to 'hot'. This is associated with the production of damage associated molecular patterns, the release of a selection of proinflammatory mediators, and the induction of inflammatory forms of cell death in cells just outside of the treatment zone. In addition to the induction of this innate immune response, histotripsy can also improve engagement of the adaptive immune system and promote systemic anti-tumor immunity targeting distal tumors and metastatic lesions. These tantalizing observations suggest that, in settings of widely metastatic disease burden, selective histotripsy of a limited number of accessible tumors could be a means of maximizing responsiveness to systemic immunotherapy. More work is certainly needed to optimize treatment strategies that best synergize histotripsy parameters with innate and adaptive immune responses. Likewise, rigorous clinical studies are still necessary to verify the presence and repeatability of these phenomena in human patients. As this technology nears regulatory approval for clinical use, it is our expectation that the insights and immunomodulatory mechanisms summarized in this review will serve as directional guides for rational clinical studies to validate and optimize the potential immunotherapeutic role of histotripsy tumor ablation.
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Affiliation(s)
- Khan M. Imran
- Graduate Program in Translational Biology, Medicine and Health, Virginia Tech, Roanoke, VA, USA
| | - Anutosh Ganguly
- Department of Surgery, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Tamalika Paul
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA
| | - Manali Powar
- Graduate Program in Translational Biology, Medicine and Health, Virginia Tech, Roanoke, VA, USA
| | - Eli Vlaisavljevich
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, USA
- Institute for Critical and Applied Science Center for Engineered Health, Virginia Tech, Blacksburg, VA, USA
| | - Clifford S. Cho
- Department of Surgery, University of Michigan Medical School, Ann Arbor, MI, USA
- Research Service, Ann Arbor VA Healthcare, Ann Arbor, MI, USA
| | - Irving C. Allen
- Graduate Program in Translational Biology, Medicine and Health, Virginia Tech, Roanoke, VA, USA
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA
- Institute for Critical and Applied Science Center for Engineered Health, Virginia Tech, Blacksburg, VA, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA, USA
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Rawnaque FS, Simon JC. The effects of elastic modulus and impurities on bubble nuclei available for acoustic cavitation in polyacrylamide hydrogels. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2022; 152:3502. [PMID: 36586847 DOI: 10.1121/10.0016445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 11/21/2022] [Indexed: 06/17/2023]
Abstract
Safety of biomedical ultrasound largely depends on controlling cavitation bubbles in vivo, yet bubble nuclei in biological tissues remain unexplored compared to water. This study evaluates the effects of elastic modulus (E) and impurities on bubble nuclei available for cavitation in tissue-mimicking polyacrylamide (PA) hydrogels. A 1.5 MHz focused ultrasound transducer with f# = 0.7 was used to induce cavitation in 17.5%, 20%, and 22.5% v/v PA hydrogels using 10-ms pulses with pressures up to peak negative pressure (p-) = 35 MPa. Cavitation was monitored at 0.075 ms through high-speed photography at 40 000 fps. At p- = 29 MPa for all hydrogels, cavitation occurred at random locations within the -6 dB focal area [9.4 × 1.2 mm (p-)]. Increasing p- to 35 MPa increased bubble location consistency and caused shock scattering in the E = 282 MPa hydrogels; as the E increased to 300 MPa, bubble location consistency decreased (p = 0.045). Adding calcium phosphate or cholesterol at 0.25% w/v or bovine serum albumin at 5% or 10% w/v in separate 17.5% PA as impurities decreased the cavitation threshold from p- = 13.2 MPa for unaltered PA to p- = 11.6 MPa, p- = 7.3 MPa, p- = 9.7 MPa, and p- = 7.5 MPa, respectively. These results suggest that both E and impurities affect the bubble nuclei available for cavitation in tissue-mimicking hydrogels.
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Affiliation(s)
- Ferdousi Sabera Rawnaque
- Graduate Program in Acoustics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Julianna C Simon
- Graduate Program in Acoustics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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Song M, Thomas GPL, Khokhlova VA, Sapozhnikov OA, Bailey MR, Maxwell AD, Yuldashev PV, Khokhlova TD. Quantitative Assessment of Boiling Histotripsy Progression Based on Color Doppler Measurements. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2022; 69:3255-3269. [PMID: 36197870 PMCID: PMC9741864 DOI: 10.1109/tuffc.2022.3212266] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Boiling histotripsy (BH) is a mechanical tissue liquefaction method that uses sequences of millisecond-long high intensity focused ultrasound (HIFU) pulses with shock fronts. The BH treatment generates bubbles that move within the sonicated volume due to acoustic radiation force. Since the velocity of the bubbles and tissue debris is expected to depend on the lesion size and liquefaction completeness, it could provide a quantitative metric of the treatment progression. In this study, the motion of bubble remnants and tissue debris immediately following BH pulses was investigated using high-pulse repetition frequency (PRF) plane-wave color Doppler ultrasound in ex vivo myocardium tissue. A 256-element 1.5 MHz spiral HIFU array with a coaxially integrated ultrasound imaging probe (ATL P4-2) produced 10 ms BH pulses to form volumetric lesions with electronic beam steering. Prior to performing volumetric BH treatments, the motion of intact myocardium tissue and anticoagulated bovine blood following isolated BH pulses was assessed as two limiting cases. In the liquid blood the velocity of BH-induced streaming at the focus reached over 200 cm/s, whereas the intact tissue was observed to move toward the HIFU array consistent with elastic rebound of tissue. Over the course of volumetric BH treatments tissue motion at the focus locations was dependent on the axial size of the forming lesion relative to the corresponding size of the HIFU focal area. For axially small lesions, the maximum velocity after the BH pulse was directed toward the HIFU transducer and monotonically increased over time from about 20-100 cm/s as liquefaction progressed, then saturated when tissue was fully liquefied. For larger lesions obtained by merging multiple smaller lesions in the axial direction, the high-speed streaming away from the HIFU transducer was observed at the point of full liquefaction. Based on these observations, the maximum directional velocity and its location along the HIFU propagation axis were proposed and evaluated as candidate metrics of BH treatment completeness.
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Bhargava A, Huang S, McPherson DD, Bader KB. Assessment of bubble activity generated by histotripsy combined with echogenic liposomes. Phys Med Biol 2022; 67:215015. [PMID: 36220055 DOI: 10.1088/1361-6560/ac994f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 10/11/2022] [Indexed: 11/05/2022]
Abstract
Objective.Histotripsy is a form of focused ultrasound therapy that uses the mechanical activity of bubbles to ablate tissue. While histotripsy alone degrades the cellular content of tissue, recent studies have demonstrated it effectively disrupts the extracellular structure of pathologic conditions such as venous thrombosis when combined with a thrombolytic drug. Rather than relying on standard administration methods, associating thrombolytic drugs with an ultrasound-triggered echogenic liposome vesicle will enable targeted, systemic drug delivery. To date, histotripsy has primarily relied on nano-nuclei inherent to the medium for bubble cloud generation, and microbubbles associated with echogenic liposomes may alter the histotripsy bubble dynamics. The objective of this work was to investigate the interaction of histotripsy pulse with echogenic liposomes.Approach.Bubble clouds were generated using a focused source in anin vitromodel of venous flow. Acoustic emissions generated during the insonation were passively acquired to assess the mechanical activity of the bubble cloud. High frame rate, pulse inversion imaging was used to track the change in echogenicity of the liposomes following histotripsy exposure.Main results.For peak negative pressures less than 20 MPa, acoustic emissions indicative of stable and inertial bubble activity were observed. As the peak negative pressure of the histotripsy excitation increased, harmonics of the excitation were observed in OFP t-ELIP solutions and plasma alone. Additional observations with high frame rate imaging indicated a transition of bubble behavior as the pulse pressure transitioned to shock wave formation.Significance.These observations suggest that a complex interaction between histotripsy pulses and echogenic liposomes that may be exploited for combination treatment approaches.
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Affiliation(s)
- Aarushi Bhargava
- Department of Radiology, University of Chicago, Chicago, IL, United States of America
| | - Shaoling Huang
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Texas Health Sciences Center-Houston, Houston, TX, United States of America
| | - David D McPherson
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Texas Health Sciences Center-Houston, Houston, TX, United States of America
| | - Kenneth B Bader
- Department of Radiology, University of Chicago, Chicago, IL, United States of America
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Thomas GPL, Khokhlova TD, Sapozhnikov OA, Wang YN, Totten SI, Khokhlova VA. In Vivo Aberration Correction for Transcutaneous HIFU Therapy Using a Multielement Array. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2022; 69:2955-2964. [PMID: 35981067 PMCID: PMC9714798 DOI: 10.1109/tuffc.2022.3200309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
One of the challenges of transcutaneous high-intensity focused ultrasound (HIFU) therapies, especially ones relying heavily on shock formation, such as boiling histotripsy (BH), is the loss of focusing from aberration induced by the heterogeneities of the body wall. Here, a methodology to execute aberration correction in vivo is proposed. A custom BH system consisting of a 1.5-MHz phased array of 256 elements connected to a Verasonics V1 system is used in pulse/echo mode on a porcine model under general anesthesia. Estimation of the time shifts needed to correct for aberration in the liver and kidney is done by maximizing the value of the coherence factor on the acquired backscattered signals. As this process requires multiple pulse/echo sequences on a moving target to converge to a solution, tracking is also implemented to ensure that the same target is used between each iteration. The method was validated by comparing the acoustic power needed to generate a boiling bubble at one target with aberration correction and at another target within a 5-mm radius without aberration correction. Results show that the aberration correction effectively lowers the acoustic power required to reach boiling by up to 45%, confirming that it indeed restored formation of the nonlinear shock front at the focus.
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Bismuth M, Katz S, Mano T, Aronovich R, Hershkovitz D, Exner AA, Ilovitsh T. Low frequency nanobubble-enhanced ultrasound mechanotherapy for noninvasive cancer surgery. NANOSCALE 2022; 14:13614-13627. [PMID: 36070492 DOI: 10.1039/d2nr01367c] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Scaling down the size of microbubble contrast agents to the nanometer level holds the promise for noninvasive cancer therapy. However, the small size of nanobubbles limits the obtained bioeffects as a result of ultrasound cavitation, when operating near the nanobubble resonance frequency. Here we show that coupled with low energy insonation at a frequency of 80 kHz, well below the resonance frequency of these agents, nanobubbles serve as noninvasive therapeutic warheads that trigger potent mechanical effects in tumors following a systemic injection. We demonstrate these capabilities in tissue mimicking phantoms, where a comparison of the acoustic response of micro- and nano-bubbles after insonation at a frequency of 250 or 80 kHz revealed that higher pressures were needed to implode the nanobubbles compared to microbubbles. Complete nanobubble destruction was achieved at a mechanical index of 2.6 for the 250 kHz insonation vs. 1.2 for the 80 kHz frequency. Thus, the 80 kHz insonation complies with safety regulations that recommend operation below a mechanical index of 1.9. In vitro in breast cancer tumor cells, the cell viability was reduced to 17.3 ± 1.7% of live cells. In vivo, in a breast cancer tumor mouse model, nanobubble tumor distribution and accumulation were evaluated by high frequency ultrasound imaging. Finally, nanobubble-mediated low frequency insonation of breast cancer tumors resulted in effective mechanical tumor ablation and tumor tissue fractionation. This approach provides a unique theranostic platform for safe, noninvasive and low energy tumor mechanotherapy.
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Affiliation(s)
- Mike Bismuth
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel.
| | - Sharon Katz
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel.
- The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Tamar Mano
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel.
| | - Ramona Aronovich
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel.
| | - Dov Hershkovitz
- Department of Pathology, Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 6997800, Israel
| | - Agata A Exner
- Departments of Radiology and Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Tali Ilovitsh
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel.
- The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
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Nanda Kumar Y, Singh Z, Wang YN, Schade GR, Kreider W, Bruce M, Vlaisavljevich E, Khokhlova TD, Maxwell AD. Development of Tough Hydrogel Phantoms to Mimic Fibrous Tissue for Focused Ultrasound Therapies. ULTRASOUND IN MEDICINE & BIOLOGY 2022; 48:1762-1777. [PMID: 35697582 PMCID: PMC9357045 DOI: 10.1016/j.ultrasmedbio.2022.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 04/28/2022] [Accepted: 05/02/2022] [Indexed: 05/30/2023]
Abstract
Tissue-mimicking gels provide a cost-effective medium to optimize histotripsy treatment parameters with immediate feedback. Agarose and polyacrylamide gels are often used to evaluate treatment outcomes as they mimic the acoustic properties and stiffness of a variety of soft tissues, but they do not exhibit high toughness, a characteristic of fibrous connective tissue. To mimic pathologic fibrous tissue found in benign prostate hyperplasia (BPH) and other diseases that are potentially treatable with histotripsy, an optically transparent hydrogel with high toughness was developed that is a hybrid of polyacrylamide and alginate. The stiffness was established using shear wave elastography (SWE) and indentometry techniques and was found to be representative of human BPH ex vivo prostate tissue. Different phantom compositions and excised ex vivo BPH tissue samples were treated with a 700-kHz histotripsy transducer at different pulse repetition frequencies. Post-treatment, the hybrid gels and the tissue samples exhibited differential reduction in stiffness as measured by SWE. On B-mode ultrasound, partially treated areas were present as hyperechoic zones and fully liquified areas as hypoechoic zones. Phase contrast microscopy of the gel samples revealed liquefaction in regions consistent with the target lesion dimensions and correlated to findings identified in tissue samples via histology. The dose required to achieve liquefaction in the hybrid gel was similar to what has been observed in ex vivo tissue and greater than that of agarose of comparable or higher Young's modulus by a factor >10. These results indicate that the developed hydrogels closely mimic elasticities found in BPH prostate ex vivo tissue and have a similar response to histotripsy treatment, thus making them a useful cost-effective alternative for developing and evaluating different treatment protocols.
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Affiliation(s)
- Yashwanth Nanda Kumar
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA.
| | - Zorawar Singh
- Department of Urology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Yak-Nam Wang
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA
| | - George R Schade
- Department of Urology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Wayne Kreider
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA
| | - Matthew Bruce
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA
| | - Eli Vlaisavljevich
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Tatiana D Khokhlova
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA; Department of Gastroenterology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Adam D Maxwell
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA; Department of Urology, University of Washington School of Medicine, Seattle, Washington, USA
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The role of anti-tumor immunity of focused ultrasound for the malignancies: depended on the different ablation categories. Int J Clin Oncol 2022; 27:1543-1553. [PMID: 35943643 DOI: 10.1007/s10147-022-02219-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 07/07/2022] [Indexed: 11/05/2022]
Abstract
Improving anti-tumor immunity has promising outcomes in eradicating malignant tumors. Tumor cells can escape from immune surveillance and killing; therefore, various strategies are continuously developing to inhibit immune escape. Focused ultrasound (FUS) has recently emerged to play an important role in immune modulation. After FUS therapy, various tumor antigens and related signals are released. The non-thermal effect of FUS strengthens the blood and lymph circulation, increases cell permeability, and helps in crossing the physical barrier like the blood-brain barrier and blood-tumor barrier. However, the different ablation of FUS is proposed to have a different anti-tumor immune effect. Therefore, we categorized the FUS ablation into thermal and non-thermal ablation and summarized possible anti-tumor immunity mechanisms.
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Simon A, Robinson F, Anzivino A, Boyer M, Hendricks-Wenger A, Guilliams D, Casey J, Grider D, Valea F, Vlaisavljevich E. Histotripsy for the Treatment of Uterine Leiomyomas: A Feasibility Study in Ex Vivo Uterine Fibroids. ULTRASOUND IN MEDICINE & BIOLOGY 2022; 48:1652-1662. [PMID: 35641394 DOI: 10.1016/j.ultrasmedbio.2022.04.214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 04/01/2022] [Accepted: 04/22/2022] [Indexed: 06/15/2023]
Abstract
Uterine fibroids (leiomyomas), the most common benign tumors in women of reproductive age, are a frequent cause of abnormal vaginal bleeding and other reproductive complaints among women. This study investigates the feasibility of using histotripsy, a non-invasive, non-thermal focused ultrasound ablation method, to ablate uterine fibroids. Human fibroid samples (n = 16) were harvested after hysterectomy or myomectomy procedures at Carilion Memorial Hospital. Histotripsy was applied to ex vivo fibroids in two sets of experiments using a 700-kHz clinical transducer to apply multicycle histotripsy pulses and a prototype 500-kHz transducer to apply single-cycle histotripsy pulses. Ultrasound imaging was used for real-time treatment monitoring, and post-treatment ablation was quantified histologically using hematoxylin and eosin and Masson trichrome stains. Results revealed that multicycle histotripsy generated diffuse cavitation in targeted fibroids, with minimal cellular ablative changes after treatment with 2000 pulses/point. Single-cycle pulsing generated well-confined bubble clouds with evidence of early coagulative necrosis on histological assessment in samples treated with 2000 pulses/point, near-complete ablation in samples treated with 4000 pulses/point and complete tissue destruction in samples treated with 10,000 pulses/point. This study illustrates that histotripsy is capable of fibroid ablation under certain pulsing parameters and warrants further investigation as an improved non-invasive ablation method for the treatment of leiomyomas.
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Affiliation(s)
- Alex Simon
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, Virginia, USA
| | - Faith Robinson
- Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA
| | - Anthony Anzivino
- Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA
| | - Maggie Boyer
- Department of Biological Systems Engineering, Virginia Tech, Blacksburg, Virginia, USA
| | - Alissa Hendricks-Wenger
- Department of Translational Biology, Medicine and Health, Virginia Tech, Blacksburg, VA, USA
| | - Danielle Guilliams
- Department of Research and Development, Carilion Clinic, Roanoke, Virginia, USA
| | - James Casey
- Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA; Department of Obstetrics and Gynecology, Carilion Clinic Gynecological Oncology, Roanoke, Virginia, USA
| | - Douglas Grider
- Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA; Dominion Pathology Associates, Roanoke, Virginia, USA
| | - Fidel Valea
- Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA; Department of Obstetrics and Gynecology, Carilion Clinic Gynecological Oncology, Roanoke, Virginia, USA
| | - Eli Vlaisavljevich
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, Virginia, USA.
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de Andrade MO, Haqshenas R, Pahk KJ, Saffari N. Mechanisms of nuclei growth in ultrasound bubble nucleation. ULTRASONICS SONOCHEMISTRY 2022; 88:106091. [PMID: 35839705 PMCID: PMC9287806 DOI: 10.1016/j.ultsonch.2022.106091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/20/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
This paper interrogates the intersections between bubble dynamics and classical nucleation theory (CNT) towards constructing a model that describes intermediary nucleation events between the extrema of cavitation and boiling. We employ Zeldovich's hydrodynamic approach to obtain a description of bubble nuclei that grow simultaneously via hydrodynamic excitation by the acoustic field and vapour transport. By quantifying the relative dominance of both mechanisms, it is then possible to discern the extent to which viscosity, inertia, surface tension and vapour transport shape the growth of bubble nuclei through non-dimensional numbers that naturally arise within the theory. The first non-dimensional number Φ12/Φ2 is analogous to the Laplace number, representing the balance between surface tension and inertial constraints to viscous effects. The second non-dimensional number δ represents how enthalpy transport into the bubble can reduce nucleation rates by cooling the surrounding liquid. This formulation adds to the current understanding of ultrasound bubble nucleation by accounting for bubble dynamics during nucleation, quantifying the physical distinctions between "boiling" and "cavitation" bubbles through non-dimensional parameters, and outlining the characteristic timescales of nucleation according to the growth mechanism of bubbles throughout the histotripsy temperature range. We observed in our simulations that viscous effects control the process of ultrasound nucleation in water-like media throughout the 0-120 °C temperature range, although this dominance decreases with increasing temperatures. Enthalpy transport was found to reduce nucleation rates for increasing temperatures. This effect becomes significant at temperatures above 30 °C and favours the creation of fewer nuclei that are larger in size. Conversely, negligible enthalpy transport at lower temperatures can enable the nucleation of dense clusters of small nuclei, such as cavitation clouds. We find that nuclei growth as modelled by the Rayleigh-Plesset equation occurs over shorter timescales than as modelled by vapour-dominated growth. This suggests that the first stage of bubble nuclei growth is hydrodynamic, and vapour transport effects can only be observed over longer timescales. Finally, we propose that this framework can be used for comparison between different experiments in bubble nucleation, towards standardisation and dosimetry of protocols.
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Affiliation(s)
| | - Reza Haqshenas
- UCL Mechanical Engineering, University College London, London, United Kingdom
| | - Ki Joo Pahk
- Department of Biomedical Engineering, Kyung Hee University, Yongin, Republic of Korea
| | - Nader Saffari
- UCL Mechanical Engineering, University College London, London, United Kingdom
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Landry TG, Gannon J, Vlaisavljevich E, Mallay MG, Woodacre JK, Croul S, Fawcett JP, Brown JA. Endoscopic Coregistered Ultrasound Imaging and Precision Histotripsy: Initial In Vivo Evaluation. BME FRONTIERS 2022; 2022:9794321. [PMID: 37850178 PMCID: PMC10521722 DOI: 10.34133/2022/9794321] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 05/06/2022] [Indexed: 10/19/2023] Open
Abstract
Objective. Initial performance evaluation of a system for simultaneous high-resolution ultrasound imaging and focused mechanical submillimeter histotripsy ablation in rat brains. Impact Statement. This study used a novel combination of high-resolution imaging and histotripsy in an endoscopic form. This would provide neurosurgeons with unprecedented accuracy in targeting and executing nonthermal ablations in minimally invasive surgeries. Introduction. Histotripsy is a safe and effective nonthermal focused ablation technique. However, neurosurgical applications, such as brain tumor ablation, are difficult due to the presence of the skull. Current devices are too large to use in the minimally invasive approaches surgeons prefer. We have developed a combined imaging and histotripsy endoscope to provide neurosurgeons with a new tool for this application. Methods. The histotripsy component had a 10 mm diameter, operating at 6.3 MHz. Affixed within a cutout hole in its center was a 30 MHz ultrasound imaging array. This coregistered pair was used to ablate brain tissue of anesthetized rats while imaging. Histological sections were examined, and qualitative descriptions of ablations and basic shape descriptive statistics were generated. Results. Complete ablations with submillimeter area were produced in seconds, including with a moving device. Ablation progress could be monitored in real time using power Doppler imaging, and B-mode was effective for monitoring post-ablation bleeding. Collateral damage was minimal, with a 100 μm maximum distance of cellular damage from the ablation margin. Conclusion. The results demonstrate a promising hardware suite to enable precision ablations in endoscopic procedures or fundamental preclinical research in histotripsy, neuroscience, and cancer.
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Affiliation(s)
- Thomas G. Landry
- School of Biomedical Engineering, Dalhousie University, Canada
- Division of Surgery, Nova Scotia Health Authority, Canada
| | - Jessica Gannon
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Virginia, USA
| | - Eli Vlaisavljevich
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Virginia, USA
| | | | | | - Sidney Croul
- Department of Pathology & Laboratory Medicine, Dalhousie University, Canada
| | - James P. Fawcett
- Department of Pharmacology, Dalhousie University, Canada
- Department of Surgery, Dalhousie University, Canada
| | - Jeremy A. Brown
- School of Biomedical Engineering, Dalhousie University, Canada
- Division of Surgery, Nova Scotia Health Authority, Canada
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45
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Bader KB, Makin IRS, Abramowicz JS. Ultrasound for Aesthetic Applications: A Review of Biophysical Mechanisms and Safety. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2022; 41:1597-1607. [PMID: 34709673 DOI: 10.1002/jum.15856] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 09/28/2021] [Accepted: 10/02/2021] [Indexed: 06/13/2023]
Abstract
Aesthetic ultrasound is used for fat reduction and to improve skin appearance. In this review, the fundamental mechanisms by which ultrasound can alter tissue are outlined. The technologies that are commercially available or under development are discussed. Finally, recommendations are made for safe and effective use of aesthetic ultrasound.
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Affiliation(s)
- Kenneth B Bader
- Department of Radiology, University of Chicago, Chicago, Illinois, USA
| | - Inder Raj S Makin
- School of Osteopathic Medicine in Arizona, A.T. Still University, Mesa, Arizona, USA
| | - Jacques S Abramowicz
- Department of Obstetrics and Gynecology, University of Chicago, Chicago, Illinois, USA
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Lafond M, Lambin T, Drainville RA, Dupré A, Pioche M, Melodelima D, Lafon C. Pancreatic Ductal Adenocarcinoma: Current and Emerging Therapeutic Uses of Focused Ultrasound. Cancers (Basel) 2022; 14:2577. [PMID: 35681557 PMCID: PMC9179649 DOI: 10.3390/cancers14112577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 11/27/2022] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) diagnosis accompanies a somber prognosis for the patient, with dismal survival odds: 5% at 5 years. Despite extensive research, PDAC is expected to become the second leading cause of mortality by cancer by 2030. Ultrasound (US) has been used successfully in treating other types of cancer and evidence is flourishing that it could benefit PDAC patients. High-intensity focused US (HIFU) is currently used for pain management in palliative care. In addition, clinical work is being performed to use US to downstage borderline resectable tumors and increase the proportion of patients eligible for surgical ablation. Focused US (FUS) can also induce mechanical effects, which may elicit an anti-tumor response through disruption of the stroma and can be used for targeted drug delivery. More recently, sonodynamic therapy (akin to photodynamic therapy) and immunomodulation have brought new perspectives in treating PDAC. The aim of this review is to summarize the current state of those techniques and share our opinion on their future and challenges.
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Affiliation(s)
- Maxime Lafond
- LabTAU, The Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Léon Bérard, Université Lyon 1, University Lyon, 69003 Lyon, France; (R.A.D.); (A.D.); (D.M.); (C.L.)
| | - Thomas Lambin
- Endoscopy Division, Édouard Herriot Hospital, 69003 Lyon, France; (T.L.); (M.P.)
| | - Robert Andrew Drainville
- LabTAU, The Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Léon Bérard, Université Lyon 1, University Lyon, 69003 Lyon, France; (R.A.D.); (A.D.); (D.M.); (C.L.)
| | - Aurélien Dupré
- LabTAU, The Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Léon Bérard, Université Lyon 1, University Lyon, 69003 Lyon, France; (R.A.D.); (A.D.); (D.M.); (C.L.)
| | - Mathieu Pioche
- Endoscopy Division, Édouard Herriot Hospital, 69003 Lyon, France; (T.L.); (M.P.)
| | - David Melodelima
- LabTAU, The Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Léon Bérard, Université Lyon 1, University Lyon, 69003 Lyon, France; (R.A.D.); (A.D.); (D.M.); (C.L.)
| | - Cyril Lafon
- LabTAU, The Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Léon Bérard, Université Lyon 1, University Lyon, 69003 Lyon, France; (R.A.D.); (A.D.); (D.M.); (C.L.)
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Fite BZ, Wang J, Ghanouni P, Ferrara KW. A Review of Imaging Methods to Assess Ultrasound-Mediated Ablation. BME FRONTIERS 2022; 2022:9758652. [PMID: 35957844 PMCID: PMC9364780 DOI: 10.34133/2022/9758652] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 02/21/2022] [Indexed: 12/18/2022] Open
Abstract
Ultrasound ablation techniques are minimally invasive alternatives to surgical resection and have rapidly increased in use. The response of tissue to HIFU ablation differs based on the relative contributions of thermal and mechanical effects, which can be varied to achieve optimal ablation parameters for a given tissue type and location. In tumor ablation, similar to surgical resection, it is desirable to include a safety margin of ablated tissue around the entirety of the tumor. A factor in optimizing ablative techniques is minimizing the recurrence rate, which can be due to incomplete ablation of the target tissue. Further, combining focal ablation with immunotherapy is likely to be key for effective treatment of metastatic cancer, and therefore characterizing the impact of ablation on the tumor microenvironment will be important. Thus, visualization and quantification of the extent of ablation is an integral component of ablative procedures. The aim of this review article is to describe the radiological findings after ultrasound ablation across multiple imaging modalities. This review presents readers with a general overview of the current and emerging imaging methods to assess the efficacy of ultrasound ablative treatments.
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Affiliation(s)
- Brett Z. Fite
- Department of Radiology, Stanford University, Palo Alto, CA 94305, USA
| | - James Wang
- Department of Radiology, Stanford University, Palo Alto, CA 94305, USA
| | - Pejman Ghanouni
- Department of Radiology, Stanford University, Palo Alto, CA 94305, USA
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Wear KA. Spatiotemporal Deconvolution of Hydrophone Response for Linear and Nonlinear Beams-Part I: Theory, Spatial-Averaging Correction Formulas, and Criteria for Sensitive Element Size. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2022; 69:1243-1256. [PMID: 35133964 PMCID: PMC9204706 DOI: 10.1109/tuffc.2022.3150186] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
This article reports spatiotemporal deconvolution methods and simple empirical formulas to correct pressure and beamwidth measurements for spatial averaging across a hydrophone sensitive element. Readers who are uninterested in hydrophone theory may proceed directly to Appendix A for an easy method to estimate spatial-averaging correction factors. Hydrophones were modeled as angular spectrum filters. Simulations modeled nine circular transducers (1-10 MHz; F/1.4-F/3.2) driven at six power levels and measured with eight hydrophones (432 beam/hydrophone combinations). For example, the model predicts that if a 200- [Formula: see text] membrane hydrophone measures a moderately nonlinear 5-MHz beam from an F/1 transducer, spatial-averaging correction factors are 33% (peak compressional pressure or pc ), 18% (peak rarefactional pressure or p ), and 18% (full width half maximum or FWHM). Theoretical and experimental estimates of spatial-averaging correction factors to were in good agreement (within 5%) for linear and moderately nonlinear signals. Criteria for maximum appropriate hydrophone sensitive element size as functions of experimental parameters were derived. Unlike the oft-cited International Electrotechnical Commission (IEC) criterion, the new criteria were derived for focusing rather than planar transducers and can accommodate nonlinear signals in addition to linear signals. Responsible reporting of hydrophone-based pressure and beamwidth measurements should always acknowledge spatial-averaging considerations.
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Woodacre JK, Landry TG, Brown JA. Fabrication and Characterization of a 5 mm × 5 mm Aluminum Lens-Based Histotripsy Transducer. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2022; 69:1442-1451. [PMID: 35171768 DOI: 10.1109/tuffc.2022.3152174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Two 5 mm by 5 mm square aluminum lenses with a 6 mm depth of focus were machined and tested for histotripsy with a 40% volume fraction 1-3 PZT-5A composite and a Meggitt Pz-39 porous ceramics lapped to 315 [Formula: see text] as the piezoelectric elements. The devices were air-backed, and an 89 [Formula: see text] layer of Parylene-C was deposited on the lens, matching aluminum to water. Both devices were driven single-ended at 5.8 MHz, their optimal frequency after bonding to the lens, with ten cycles at a PRF of 1 kHz. The composite-based device showed no sign of free-field cavitation in water up to a drive level of 600 V, whereas the Pz39-based device was able to cavitate in water at a drive level of 220 V. In vivo ablation of a rat brain tissue was demonstrated through an opening in the skull and required the drive voltage be increased to 280 V. The ablation was monitored using B-mode imaging with an endoscopic 30 MHz ultrasound phased array and power Doppler overlay. Ablation was maintained for 12 s and, in the power Doppler image, the ablation zone grew steadily over this time to 1.9 mm by 3.4 mm. Immediately after treatment, the ablated area appeared anechoic, slowly filling with specular material.
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Wallach EL, Shekhar H, Flores-Guzman F, Hernandez SL, Bader KB. Histotripsy Bubble Cloud Contrast With Chirp-Coded Excitation in Preclinical Models. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2022; 69:787-794. [PMID: 34748487 DOI: 10.1109/tuffc.2021.3125922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Histotripsy is a focused ultrasound therapy for tissue ablation via the generation of bubble clouds. These effects can be achieved noninvasively, making sensitive and specific bubble imaging essential for histotripsy guidance. Plane-wave ultrasound imaging can track bubble clouds with an excellent temporal resolution, but there is a significant reduction in echoes when deep-seated organs are targeted. Chirp-coded excitation uses wideband, long-duration imaging pulses to increase signals at depth and promote nonlinear bubble oscillations. In this study, we evaluated histotripsy bubble contrast with chirp-coded excitation in scattering gel phantoms and a subcutaneous mouse tumor model. A range of imaging pulse durations were tested, and compared to a standard plane-wave pulse sequence. Received chirped signals were processed with matched filters to highlight components associated with either fundamental or subharmonic (bubble-specific) frequency bands. The contrast-to-tissue ratio (CTR) was improved in scattering media for subharmonic contrast relative to fundamental contrast (both chirped and standard imaging pulses) with the longest-duration chirped-pulse tested (7.4 [Formula: see text] pulse duration). The CTR was improved for subharmonic contrast relative to fundamental contrast (both chirped and standard imaging pulses) by 4.25 dB ± 1.36 dB in phantoms and 3.84 dB ± 6.42 dB in vivo. No systematic changes were observed in the bubble cloud size or dissolution rate between sequences, indicating image resolution was maintained with the long-duration imaging pulses. Overall, this study demonstrates the feasibility of specific histotripsy bubble cloud visualization with chirp-coded excitation.
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