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Zhou M, Zhou W, Yang H, Cao L, Li M, Yin P, Zhou Y. Molecular Modeling of Shockwave-Mediated Blood-Brain Barrier Opening for Targeted Drug Delivery. ACS APPLIED MATERIALS & INTERFACES 2024. [PMID: 38622933 DOI: 10.1021/acsami.4c00812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Bubble-enhanced shock waves induce the transient opening of the blood-brain barrier (BBB) providing unique advantages for targeted drug delivery of brain tumor therapy, but little is known about the molecular details of this process. Based on our BBB model including 28 000 lipids and 280 tight junction proteins and coarse-grained dynamics simulations, we provided the molecular-level delivery mechanism of three typical drugs for the first time, including the lipophilic paclitaxel, hydrophilic gemcitabine, and siRNA encapsulated in liposome, across the BBB. The results show that the BBB is more difficult to be perforated by shock-induced jets than the human brain plasma membrane (PM), requiring higher shock wave speeds. For the pores formed, the BBB exhibits a greater ability to self-heal than PM. Hydrophobic paclitaxel can cross the BBB and be successfully absorbed, but the amount is only one-third of that of PM; however, the absorption of hydrophilic gemcitabine was almost negligible. Liposome-loaded siRNAs only stayed in the first layer of the BBB. The mechanism analysis shows that increasing the bubble size can promote drug absorption while reducing the risk of higher shock wave overpressure. An exponential function was proposed to describe the relation between bubble and overpressure, which can be extended to the experimental microbubble scale. The calculated overpressure is consistent with the experimental result. These molecular-scale details on shock-assisted BBB opening for targeted drug delivery would guide and assist experimental attempts to promote the application of this strategy in the clinical treatment of brain tumors.
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Affiliation(s)
- Mi Zhou
- Institute of Chemical Materials, Chinese Academy of Engineering and Physics, Mianyang 621900, China
- School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Wenyu Zhou
- Institute of Chemical Materials, Chinese Academy of Engineering and Physics, Mianyang 621900, China
| | - Hong Yang
- Institute of Chemical Materials, Chinese Academy of Engineering and Physics, Mianyang 621900, China
| | - Luoxia Cao
- Institute of Chemical Materials, Chinese Academy of Engineering and Physics, Mianyang 621900, China
| | - Ming Li
- Institute of Chemical Materials, Chinese Academy of Engineering and Physics, Mianyang 621900, China
| | - Ping Yin
- Institute of Chemical Materials, Chinese Academy of Engineering and Physics, Mianyang 621900, China
- School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Yang Zhou
- Institute of Chemical Materials, Chinese Academy of Engineering and Physics, Mianyang 621900, China
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2
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Eleni Karakatsani M, Estrada H, Chen Z, Shoham S, Deán-Ben XL, Razansky D. Shedding light on ultrasound in action: Optical and optoacoustic monitoring of ultrasound brain interventions. Adv Drug Deliv Rev 2024; 205:115177. [PMID: 38184194 PMCID: PMC11298795 DOI: 10.1016/j.addr.2023.115177] [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: 10/09/2023] [Revised: 12/27/2023] [Accepted: 12/31/2023] [Indexed: 01/08/2024]
Abstract
Monitoring brain responses to ultrasonic interventions is becoming an important pillar of a growing number of applications employing acoustic waves to actuate and cure the brain. Optical interrogation of living tissues provides a unique means for retrieving functional and molecular information related to brain activity and disease-specific biomarkers. The hybrid optoacoustic imaging methods have further enabled deep-tissue imaging with optical contrast at high spatial and temporal resolution. The marriage between light and sound thus brings together the highly complementary advantages of both modalities toward high precision interrogation, stimulation, and therapy of the brain with strong impact in the fields of ultrasound neuromodulation, gene and drug delivery, or noninvasive treatments of neurological and neurodegenerative disorders. In this review, we elaborate on current advances in optical and optoacoustic monitoring of ultrasound interventions. We describe the main principles and mechanisms underlying each method before diving into the corresponding biomedical applications. We identify areas of improvement as well as promising approaches with clinical translation potential.
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Affiliation(s)
- Maria Eleni Karakatsani
- Institute for Biomedical Engineering and Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, Switzerland; Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Switzerland
| | - Héctor Estrada
- Institute for Biomedical Engineering and Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, Switzerland; Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Switzerland
| | - Zhenyue Chen
- Institute for Biomedical Engineering and Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, Switzerland; Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Switzerland
| | - Shy Shoham
- Department of Ophthalmology and Tech4Health and Neuroscience Institutes, NYU Langone Health, NY, USA
| | - Xosé Luís Deán-Ben
- Institute for Biomedical Engineering and Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, Switzerland; Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Switzerland.
| | - Daniel Razansky
- Institute for Biomedical Engineering and Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, Switzerland; Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Switzerland.
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He X, Oshino S, Hosomi K, Kanemoto M, Tani N, Kishima H. Characteristics of Pain During MRI-Guided Focused Ultrasound Thalamotomy. Neurosurgery 2023; 93:358-365. [PMID: 36861986 PMCID: PMC10319367 DOI: 10.1227/neu.0000000000002420] [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: 08/25/2022] [Accepted: 12/22/2022] [Indexed: 03/03/2023] Open
Abstract
BACKGROUND Magnetic resonance imaging-guided focused ultrasound (MRgFUS) has become popular as an incisionless mode of neurosurgical treatment. However, head pain during sonication is common and its pathophysiology remains poorly understood. OBJECTIVE To explore the characteristics of head pain occurring during MRgFUS thalamotomy. METHODS Our study comprised 59 patients who answered questions about the pain they experienced during unilateral MRgFUS thalamotomy. The location and features of pain were investigated using a questionnaire including the numerical rating scale (NRS) to estimate maximum pain intensity and the Japanese version of the Short Form of McGill Pain Questionnaire 2 to evaluate the quantitative and qualitative dimensions of pain. Several clinical factors were investigated for possible correlation with pain intensity. RESULTS Forty-eight patients (81%) reported sonication-related head pain, and the degree of pain was severe (NRS score ≥ 7) in 39 patients (66%). The distribution of sonication-related pain was "localized" in 29 (49%) and "diffuse" in 16 (27%); the most frequent location was the "occipital" region. The pain features most frequently reported were those in the "affective" subscale of the Short Form of McGill Pain Questionnaire 2. Patients with diffuse pain had a higher NRS score and lower skull density ratio than did patients with localized pain. The NRS score negatively correlated with tremor improvement at 6 months post-treatment. CONCLUSION Most patients in our cohort experienced pain during MRgFUS. The distribution and intensity of pain varied according to the skull density ratio, indicating that the pain might have had different origins. Our results may contribute to the improvement of pain management during MRgFUS.
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Affiliation(s)
- Xin He
- Department of Neurosurgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Satoru Oshino
- Department of Neurosurgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Koichi Hosomi
- Department of Neurosurgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Manabu Kanemoto
- Department of Neurosurgery, Saito Yukoukai Hospital, Ibaraki, Osaka, Japan
| | - Naoki Tani
- Department of Neurosurgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Haruhiko Kishima
- Department of Neurosurgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
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Lascaud J, Parodi K. On the potential biological impact of radiation-induced acoustic emissions during ultra-high dose rate electron radiotherapy: a preliminary study. Phys Med Biol 2023; 68. [PMID: 36749987 DOI: 10.1088/1361-6560/acb9ce] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 02/07/2023] [Indexed: 02/09/2023]
Abstract
Ionizing radiation pulses delivered at ultra-high dose rates in emerging FLASH radiotherapy can result in high-intensity low-frequency thermoacoustic emissions that may have a biological impact. This study aims at providing insights into the thermoacoustic emissions expected during FLASH radiotherapy and their likelihood of inducing acoustic cavitation. The characteristics of acoustic waves induced by the energy deposition of a pulsed electron beam similar to previous pre-clinical FLASH radiotherapy studies and their propagation in murine head-like phantoms are investigated in-silico. The results show that the generated pressures are sufficient to produce acoustic cavitation due to resonance in the irradiated object. It suggests that thermoacoustics may, in some irradiation scenarios, contribute to the widely misunderstood FLASH effect or cause adverse effects if not taken into account at the treatment planning stage.
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Affiliation(s)
- Julie Lascaud
- Department of Medical Physics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Katia Parodi
- Department of Medical Physics, Ludwig-Maximilians-Universität München, Munich, Germany
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Advances in applications of head mounted devices (HMDs): Physical techniques for drug delivery and neuromodulation. J Control Release 2023; 354:810-820. [PMID: 36709924 DOI: 10.1016/j.jconrel.2023.01.061] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/23/2023] [Accepted: 01/23/2023] [Indexed: 01/31/2023]
Abstract
Head-mounted medical devices (HMDs) are disruptive inventions representing laboratories and clinical institutions worldwide are climbing the apexes of brain science. These complex devices are inextricably linked with a wide range knowledge containing the Physics, Imaging, Biomedical engineering, Biology and Pharmacology, particularly could be specifically designed for individuals, and finally exerting integrated bio-effect. The salient characteristics of them are non-invasive intervening in human brain's physiological structures, and alterating the biological process, such as thermal ablating the tumor, opening the BBB to deliver drugs and neuromodulating to enhance cognitive performance or manipulate prosthetic. The increasing demand and universally accepted of them have set off a dramatic upsurge in HMDs' studies, seminal applications of them span from clinical use to psychiatric disorders and neurological modulation. With subsequent pre-clinical studies and human trials emerging, the mechanisms of transcranial stimulation methods of them were widely studied, and could be basically came down to three notable approach: magnetic, electrical and ultrasonic stimulation. This review provides a comprehensive overviews of their stimulating mechanisms, and recent advances in clinic and military. We described the potential impact of HMDs on brain science, and current challenges to extensively adopt them as promising alternative treating tools.
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Lu N, Hall TL, Sukovich JR, Choi SW, Snell J, McDannold N, Xu Z. Two-step aberration correction: application to transcranial histotripsy. Phys Med Biol 2022; 67:10.1088/1361-6560/ac72ed. [PMID: 35609619 PMCID: PMC9234948 DOI: 10.1088/1361-6560/ac72ed] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 05/24/2022] [Indexed: 11/11/2022]
Abstract
Objective: Phase aberration correction is essential in transcranial histotripsy to compensate for focal distortion caused by the heterogeneity of the intact skull bone. This paper improves the 2-step aberration correction (AC) method that has been previously presented and develops an AC workflow that fits in the clinical environment, in which the computed tomography (CT)-based analytical approach was first implemented, followed by a cavitation-based approach using the shockwaves from the acoustic cavitation emission (ACE).Approach:A 700 kHz, 360-element hemispherical transducer array capable of transmit-and-receive on all channels was used to transcranially generate histotripsy-induced cavitation and acquire ACE shockwaves. For CT-AC, two ray-tracing models were investigated: a forward ray-tracing model (transducer-to-focus) in the open-source software Kranion, and an in-house backward ray-tracing model (focus-to-transducer) accounting for refraction and the sound speed variation in skulls. Co-registration was achieved by aligning the skull CT data to the skull surface map reconstructed using the acoustic pulse-echo method. For ACE-AC, the ACE signals from the collapses of generated bubbles were aligned by cross-correlation to estimate the corresponding time delays.Main results:The performance of the 2-step method was tested with 3 excised human calvariums placed at 2 different locations in the transducer array. Results showed that the 2-step AC achieved 90 ± 7% peak focal pressure compared to the gold standard hydrophone correction. It also reduced the focal shift from 0.84 to 0.30 mm and the focal volume from 10.6 to 2.0 mm3on average compared to the no AC cases.Significance:The 2-step AC yielded better refocusing compared to either CT-AC or ACE-AC alone and can be implemented in real-time for transcranial histotripsy brain therapy.
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Affiliation(s)
- Ning Lu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, United States of America
| | - Timothy L Hall
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, United States of America
| | - Jonathan R Sukovich
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, United States of America
| | - Sang Won Choi
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, United States of America
| | - John Snell
- Focused Ultrasound Foundation, Charlottesville, United States of America
| | - Nathan McDannold
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Zhen Xu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, United States of America
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Baek H, Lockwood D, Mason EJ, Obusez E, Poturalski M, Rammo R, Nagel SJ, Jones SE. Clinical Intervention Using Focused Ultrasound (FUS) Stimulation of the Brain in Diverse Neurological Disorders. Front Neurol 2022; 13:880814. [PMID: 35614924 PMCID: PMC9124976 DOI: 10.3389/fneur.2022.880814] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 04/07/2022] [Indexed: 12/02/2022] Open
Abstract
Various surgical techniques and pharmaceutical treatments have been developed to improve the current technologies of treating brain diseases. Focused ultrasound (FUS) is a new brain stimulation modality that can exert a therapeutic effect on diseased brain cells, with this effect ranging from permanent ablation of the pathological neural circuit to transient excitatory/inhibitory modulation of the neural activity depending on the acoustic energy of choice. With the development of intraoperative imaging technology, FUS has become a clinically available noninvasive neurosurgical option with visual feedback. Over the past 10 years, FUS has shown enormous potential. It can deliver acoustic energy through the physical barrier of the brain and eliminate abnormal brain cells to treat patients with Parkinson's disease and essential tremor. In addition, FUS can help introduce potentially beneficial therapeutics at the exact brain region where they need to be, bypassing the brain's function barrier, which can be applied for a wide range of central nervous system disorders. In this review, we introduce the current FDA-approved clinical applications of FUS, ranging from thermal ablation to blood barrier opening, as well as the emerging applications of FUS in the context of pain control, epilepsy, and neuromodulation. We also discuss the expansion of future applications and challenges. Broadening FUS technologies requires a deep understanding of the effect of ultrasound when targeting various brain structures in diverse disease conditions in the context of skull interface, anatomical structure inside the brain, and pathology.
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Affiliation(s)
- Hongchae Baek
- Cleveland Clinic, Imaging Institute, Cleveland, OH, United States
- Center for Neurological Restoration, Cleveland Clinic, Neurological Institute, Cleveland, OH, United States
| | - Daniel Lockwood
- Cleveland Clinic, Imaging Institute, Cleveland, OH, United States
| | | | - Emmanuel Obusez
- Cleveland Clinic, Imaging Institute, Cleveland, OH, United States
| | | | - Richard Rammo
- Center for Neurological Restoration, Cleveland Clinic, Neurological Institute, Cleveland, OH, United States
| | - Sean J. Nagel
- Center for Neurological Restoration, Cleveland Clinic, Neurological Institute, Cleveland, OH, United States
| | - Stephen E. Jones
- Cleveland Clinic, Imaging Institute, Cleveland, OH, United States
- *Correspondence: Stephen E. Jones
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Barbato G, Nisticò R, Triaca V. Exploiting Focused Ultrasound to Aid Intranasal Drug Delivery for Brain Therapy. Front Pharmacol 2022; 13:786475. [PMID: 35496270 PMCID: PMC9046653 DOI: 10.3389/fphar.2022.786475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 03/07/2022] [Indexed: 11/13/2022] Open
Abstract
Novel effective therapeutic strategies are needed to treat brain neurodegenerative diseases and to improve the quality of life of patients affected by Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), Amyotrophic Lateral sclerosis (ALS) as well as other brain conditions. At present no effective treatment options are available; current therapeutics for neurodegenerative diseases (NDs) improve cognitive symptoms only transiently and in a minor number of patients. Further, most of the amyloid-based phase III clinical trials recently failed in AD, in spite of promising preclinical and phase I-II clinical trials, further pinpointing the need for a better knowledge of the early mechanisms of disease as well as of more effective routes of drug administration. In fact, beyond common pathological events and molecular substrates, each of these diseases preferentially affect defined subpopulations of neurons in specific neuronal circuits (selective neuronal vulnerability), leading to the typical age-related clinical profile. In this perspective, key to successful drug discovery is a robust and reproducible biological validation of potential new molecular targets together with a concomitant set up of protocols/tools for efficient and targeted brain delivery to a specific area of interest. Here we propose and discuss Focused UltraSound aided drug administration as a specific and novel technical approach to achieve optimal concentration of the drug at the target area of interest. We will focus on drug delivery to the brain through the nasal route coupled to FUS as a promising approach to achieve neuroprotection and rescue of cognitive decline in several NDs.
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Affiliation(s)
- Gaetano Barbato
- Inno-Sol Srl, Rome, Italy
- Department of Biology, School of Pharmacy, University of Tor Vergata, Rome, Italy
- *Correspondence: Gaetano Barbato, ; Robert Nisticò, ; Viviana Triaca,
| | - Robert Nisticò
- Department of Biology, School of Pharmacy, University of Tor Vergata, Rome, Italy
- Laboratory of Pharmacology of Synaptic Plasticity, Fondazione EBRI Rita Levi Montalcini, Rome, Italy
- *Correspondence: Gaetano Barbato, ; Robert Nisticò, ; Viviana Triaca,
| | - Viviana Triaca
- Institute of Biochemistry and Cell Biology (IBBC), National Research Council (CNR), International Campus A. Buzzati-Traverso, Rome, Italy
- *Correspondence: Gaetano Barbato, ; Robert Nisticò, ; Viviana Triaca,
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Mensah-Brown KG, Yang AI, Hitti FL, Henry L, Heman-Ackah SM, Chaibainou H, Baltuch GH. Magnetic Resonance-Guided Focused Ultrasound Thalamotomy for Essential Tremor Under General Anesthesia: Technical Note. Oper Neurosurg (Hagerstown) 2022; 22:255-260. [PMID: 35147587 DOI: 10.1227/ons.0000000000000119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 11/03/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy is an incisionless therapy for the treatment of medication-resistant essential tremor. Although its safety and efficacy has been demonstrated, MRgFUS is typically performed with the patient awake, with intraprocedural neurological assessments to guide lesioning. OBJECTIVE To report the first case of MRgFUS thalamotomy under general anesthesia in a patient whose medical comorbidities prohibit him from being in a supine position without a secured airway. METHODS The dentatorubrothalamic tract was directly targeted. Two sonications reaching lesional temperatures (≥54°C) were delivered without any complications. RESULTS Lesioning was confirmed on intraoperative magnetic resonance imaging, and the patient experienced 89% improvement in his tremor postoperatively. CONCLUSION This demonstrates the safety and feasibility of MRgFUS thalamotomy under general anesthesia without the benefit of intraprocedural neurological assessments.
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Affiliation(s)
- Kobina G Mensah-Brown
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Andrew I Yang
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Frederick L Hitti
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Sabrina M Heman-Ackah
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Hanane Chaibainou
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Gordon H Baltuch
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Stieglitz LH, Oertel MF, Accolla EA, Bally J, Bauer R, Baumann CR, Benninger D, Bohlhalter S, Büchele F, Hägele-Link S, Kägi G, Krack P, Krüger MT, Mahendran S, Möller JC, Mylius V, Piroth T, Werner B, Kaelin-Lang A. Consensus Statement on High-Intensity Focused Ultrasound for Functional Neurosurgery in Switzerland. Front Neurol 2021; 12:722762. [PMID: 34630296 PMCID: PMC8493868 DOI: 10.3389/fneur.2021.722762] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/18/2021] [Indexed: 11/17/2022] Open
Abstract
Background: Magnetic resonance-guided high-intensity focused ultrasound (MRgHiFUS) has evolved into a viable ablative treatment option for functional neurosurgery. However, it is not clear yet, how this new technology should be integrated into current and established clinical practice and a consensus should be found about recommended indications, stereotactic targets, patient selection, and outcome measurements. Objective: To sum up and unify current knowledge and clinical experience of Swiss neurological and neurosurgical communities regarding MRgHiFUS interventions for brain disorders to be published as a national consensus paper. Methods: Eighteen experienced neurosurgeons and neurologists practicing in Switzerland in the field of movement disorders and one health physicist representing 15 departments of 12 Swiss clinical centers and 5 medical societies participated in the workshop and contributed to the consensus paper. All experts have experience with current treatment modalities or with MRgHiFUS. They were invited to participate in two workshops and consensus meetings and one online meeting. As part of workshop preparations, a thorough literature review was undertaken and distributed among participants together with a list of relevant discussion topics. Special emphasis was put on current experience and practice, and areas of controversy regarding clinical application of MRgHiFUS for functional neurosurgery. Results: The recommendations addressed lesioning for treatment of brain disorders in general, and with respect to MRgHiFUS indications, stereotactic targets, treatment alternatives, patient selection and management, standardization of reporting and follow-up, and initialization of a national registry for interventional therapies of movement disorders. Good clinical evidence is presently only available for unilateral thalamic lesioning in treating essential tremor or tremor-dominant Parkinson's disease and, to a minor extent, for unilateral subthalamotomy for Parkinson's disease motor features. However, the workgroup unequivocally recommends further exploration and adaptation of MRgHiFUS-based functional lesioning interventions and confirms the need for outcome-based evaluation of these approaches based on a unified registry. MRgHiFUS and DBS should be evaluated by experts familiar with both methods, as they are mutually complementing therapy options to be appreciated for their distinct advantages and potential. Conclusion: This multidisciplinary consensus paper is a representative current recommendation for safe implementation and standardized practice of MRgHiFUS treatments for functional neurosurgery in Switzerland.
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Affiliation(s)
| | - Markus F Oertel
- Department of Neurosurgery, University Hospital Zurich, Zurich, Switzerland
| | - Ettore A Accolla
- Neurology Unit, Department of Internal Medicine, Hôpital Fribourgeois (HFR)-Cantonal Hospital Fribourg, University of Fribourg, Fribourg, Switzerland
| | - Julien Bally
- Department of Neurology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.,Department of Neurology, Geneva University Hospital and University of Geneva, Geneva, Switzerland
| | - Roland Bauer
- Department of Neurosurgery, Cantonal Hospital Aarau, Aarau, Switzerland
| | | | - David Benninger
- Department of Neurology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Stephan Bohlhalter
- Neurocenter, Lucerne Cantonal Hospital, University of Zurich, Zurich, Switzerland
| | - Fabian Büchele
- Department of Neurology, University Hospital Zurich, Zurich, Switzerland
| | - Stefan Hägele-Link
- Department of Neurology, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
| | - Georg Kägi
- Department of Neurology, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
| | - Paul Krack
- Department of Neurology, Inselspital, University Bern, Bern, Switzerland
| | - Marie T Krüger
- Department of Neurosurgery, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
| | - Sujitha Mahendran
- Department of Neurology, University Hospital Zurich, Zurich, Switzerland
| | - J Carsten Möller
- Parkinson Center, Center for Neurological Rehabilitation, Zihlschlacht, Switzerland
| | - Veit Mylius
- Department of Neurology, Center for Neurorehabilitation, Valens, Switzerland
| | - Tobias Piroth
- Department of Neurology, Cantonal Hospital Aarau, Aarau, Switzerland
| | - Beat Werner
- Center for Magnetic Resonance (MR) Research, University Children's Hospital Zurich, Zurich, Switzerland
| | - Alain Kaelin-Lang
- Department of Neurology, Inselspital, University Bern, Bern, Switzerland.,Neurocenter of Southern Switzerland Ente Ospedaliero Cantonale (EOC), Regional Hospital Lugano, Lugano, Switzerland.,Faculty of Biomedical Neurosciences, Università Della Svizzera Italiana, Lugano, Switzerland
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11
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López-Aguirre M, Caballero-Insaurriaga J, Urso D, Rodríguez-Rojas R, Máñez-Miró JU, Del-Alamo M, Rachmilevitch I, Martínez-Fernández R, Pineda-Pardo JA. Lesion 3D modeling in transcranial MR-guided focused ultrasound thalamotomy. Magn Reson Imaging 2021; 80:71-80. [PMID: 33905832 DOI: 10.1016/j.mri.2021.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 04/08/2021] [Accepted: 04/21/2021] [Indexed: 01/21/2023]
Abstract
Transcranial magnetic resonance-guided focused ultrasound (tMRgFUS) allows to perform incisionless thermoablation of deep brain structures. This feature makes it a very useful tool for the treatment of multiple neurological and psychiatric disorders. Currently, feedback of the thermoablation process is based on peak temperature readings assessed on real-time two-dimensional MRI thermometry. However, an accurate methodology relating thermal dosimetry with three-dimensional topography and temporal evolution of the lesion is still to be defined, thus hurdling the establishment of well-defined, evidence-based criteria to perform safe and effective treatments. In here we propose threshold-based thermoablation models to predict the volumetric topography of the lesion (whole lesion and necrotic core) in the short-to-mid-term based on thermal dosimetry estimated from intra-treatment MRI thermometry. To define and validate our models we retrospectively analyzed the data of sixty-three tMRgFUS thalamotomies for treating tremor. We used intra-treatment MRI thermometry to estimate whole-treatment three-dimensional thermal dose maps, defined either as peak temperature reached (Tmax) or thermal isoeffective dose (TID). Those maps were thresholded to find the dosimetric level that maximize the agreement (Sorensen-Dice coefficient - SDc) with the boundaries of the whole lesion and its core, assessed on T2w images 1-day (post-24h) and 3-months (post-3M) after treatment. Best predictions were achieved for the whole lesion at post-24h (SDc = 0.71), with Tmax /TID over 50.0 °C/90.5 CEM43. The core at post-24h and whole lesion at post-3M lesions reported a similar behavior in terms of shape accuracy (SDc ~0.35), and thermal dose thresholds ~55 °C/4100.0 CEM43. Finally, the optimal levels for post-3M core lesions were 55.5 °C/5800.0 CEM43 (SDc = 0.21). These thermoablation models could contribute to the real-time decision-making process and improve the outcome of tMRgFUS interventions both in terms of safety and efficacy.
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Affiliation(s)
- Miguel López-Aguirre
- HM CINAC, Centro Integral de Neurociencias AC, Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain; Universidad Complutense de Madrid, Madrid, Spain
| | - Jaime Caballero-Insaurriaga
- HM CINAC, Centro Integral de Neurociencias AC, Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain; Universidad Politécnica de Madrid, Madrid, Spain
| | - Daniele Urso
- King's College (KCL), Institute of Psychiatry, Psychology & Neuroscience, London, United Kingdom
| | - Rafael Rodríguez-Rojas
- HM CINAC, Centro Integral de Neurociencias AC, Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain; Universidad San Pablo CEU, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas Instituto Carlos III, Madrid, Spain
| | - Jorge U Máñez-Miró
- HM CINAC, Centro Integral de Neurociencias AC, Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain
| | - Marta Del-Alamo
- HM CINAC, Centro Integral de Neurociencias AC, Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain
| | | | - Raúl Martínez-Fernández
- HM CINAC, Centro Integral de Neurociencias AC, Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain; Universidad San Pablo CEU, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas Instituto Carlos III, Madrid, Spain
| | - José A Pineda-Pardo
- HM CINAC, Centro Integral de Neurociencias AC, Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain; Universidad San Pablo CEU, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas Instituto Carlos III, Madrid, Spain.
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12
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Chang KW, Rachmilevitch I, Chang WS, Jung HH, Zadicario E, Prus O, Chang JW. Safety and Efficacy of Magnetic Resonance-Guided Focused Ultrasound Surgery With Autofocusing Echo Imaging. Front Neurosci 2021; 14:592763. [PMID: 33510610 PMCID: PMC7835836 DOI: 10.3389/fnins.2020.592763] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 11/30/2020] [Indexed: 02/01/2023] Open
Abstract
Objective Magnetic resonance-guided focused ultrasound surgery (MRgFUS) lesioning is a new treatment for brain disorders. However, the skull is a major barrier of ultrasound sonication in MRgFUS because it has an irregular surface and varies its size and shape among individuals. We recently developed the concept of skull density ratio (SDR) to select candidates for MRgFUS from among patients with essential tremor (ET). However, SDR is not the only factor contributing to successful MRgFUS lesioning treatment-refining the target through exact measurement of the ultrasonic echo in the transducer also improves treatment efficacy. In the present study, we carried out MRgFUS lesioning using an autofocusing echo imaging technique. We aimed to evaluate the safety and efficacy of this new approach, especially in patients with low SDR in whom previous focusing methods have failed. Methods From December 2019 to March 2020, we recruited 10 patients with ET or Parkinson's disease (PD) who had a low SDR. Two patients dropped out of the trial due to the screening failure of other medical diseases. In total, eight patients were included: six with ET who underwent MRgFUS thalamotomy and two with PD who underwent MRgFUS pallidotomy. The autofocusing echo imaging technique was used in all cases. Results The mean SDR of the patients with ET was 0.34 (range: 0.29-0.39), while that of the patients with PD was 0.41 (range: 0.38-0.44). The mean skull volume of patients with ET was 280.57 cm3 (range: 227-319 cm3), while that of the patients with PD was 287.13 cm3 (range: 271-303 cm3). During MRgFUS, a mean of 15 sonications were performed, among which a mean of 5.63 used the autofocusing technique. The mean maximal temperature (Tmax) achieved was 55.88°C (range: 52-59°C), while the mean energy delivered was 34.75 kJ (range: 20-42 kJ) among all patients. No serious adverse events occurred during or after treatment. Tmax or sonication factors (skull volume, SDR, sonication number, autofocusing score, similarity score, energy range, and power) were not correlated with autofocusing technique (p > 0.05, autofocusing score showed a p-value of 0.071). Conclusion Using autofocusing echo imaging lesioning, a safe and efficient MRgFUS treatment, is available even for patients with a low SDR. Therefore, the indications for MRgFUS lesioning could be expanded to include patients with ET who have an SDR < 0.4 and those with PD who have an SDR < 0.45. Clinical Trial Registration clinicaltrials.gov, identifier: NCT03935581.
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Affiliation(s)
- Kyung Won Chang
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | | | - Won Seok Chang
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - Hyun Ho Jung
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | | | | | - Jin Woo Chang
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, South Korea
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13
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Yamamoto K, Ito H, Fukutake S, Odo T, Kamei T, Yamaguchi T, Taira T. Factors Associated with Heating Efficiency in Transcranial Focused Ultrasound Therapy. Neurol Med Chir (Tokyo) 2020; 60:594-599. [PMID: 33162467 PMCID: PMC7803702 DOI: 10.2176/nmc.oa.2020-0225] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Transcranial magnetic resonance-guided focused ultrasound (FUS) therapy is a less invasive stereotactic treatment for tremor and other movement disorders. A sufficiently high temperature in the target brain tissue is crucial during ablation procedures for good outcomes. Therefore, maximizing the heating efficiency is critical in cases where high temperature cannot be achieved because of patient-related characteristics. However, a strategy to achieve the desired therapeutic temperature with FUS has not yet been established. This study aimed to investigate the procedural factors associated with heating efficiency in FUS. We retrospectively reviewed and analyzed data from patients who underwent FUS for ventralis intermedius (VIM) nucleus thalamotomy. In all, 30 consecutive patients were enrolled. 18 with essential tremor (ET), 11 with tremor-dominant Parkinson’s disease (TDPD), and 1 with Holmes tremor. Multivariate regression analysis showed that decline in heating efficiency was associated with lower skull density ratio (SDR) and a greater subtotal rise in temperature until the previous sonication. To maximize heating efficiency, the temperature increase should be set to the least value in the target alignment and verification phases, and subsequently should be increased sufficiently in the treatment phase. This strategy may be particularly beneficial in cases where high ablation temperatures cannot be achieved because of patient-related characteristics. Importantly, a broad patient population would benefit from this strategy as it could reduce the need for high energy to achieve therapeutic temperatures, thereby decreasing the risks of adverse events.
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Affiliation(s)
- Kazuaki Yamamoto
- Department of Neurosurgery, Tokyo Women's Medical University.,Department of Neurosurgery, Shonan Kamakura General Hospital
| | - Hisashi Ito
- Department of Neurology, Shonan Fujisawa Tokushukai Hospital
| | | | - Takashi Odo
- Department of Neurology, Shonan Fujisawa Tokushukai Hospital
| | - Tetsumasa Kamei
- Department of Neurology, Shonan Fujisawa Tokushukai Hospital
| | - Toshio Yamaguchi
- Research Institute of Diagnostic Imaging, Shin-Yurigaoka General Hospital
| | - Takaomi Taira
- Department of Neurosurgery, Tokyo Women's Medical University
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14
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Meng Y, Hynynen K, Lipsman N. Applications of focused ultrasound in the brain: from thermoablation to drug delivery. Nat Rev Neurol 2020; 17:7-22. [PMID: 33106619 DOI: 10.1038/s41582-020-00418-z] [Citation(s) in RCA: 192] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2020] [Indexed: 02/07/2023]
Abstract
Focused ultrasound (FUS) is a disruptive medical technology, and its implementation in the clinic represents the culmination of decades of research. Lying at the convergence of physics, engineering, imaging, biology and neuroscience, FUS offers the ability to non-invasively and precisely intervene in key circuits that drive common and challenging brain conditions. The actions of FUS in the brain take many forms, ranging from transient blood-brain barrier opening and neuromodulation to permanent thermoablation. Over the past 5 years, we have seen a dramatic expansion of indications for and experience with FUS in humans, with a resultant exponential increase in academic and public interest in the technology. Applications now span the clinical spectrum in neurological and psychiatric diseases, with insights still emerging from preclinical models and human trials. In this Review, we provide a comprehensive overview of therapeutic ultrasound and its current and emerging indications in the brain. We examine the potential impact of FUS on the landscape of brain therapies as well as the challenges facing further advancement and broader adoption of this promising minimally invasive therapeutic alternative.
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Affiliation(s)
- Ying Meng
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.,Sunnybrook Research Institute, Hurvitz Brain Sciences Program, Harquail Centre for Neuromodulation, Toronto, ON, Canada.,Institute of Medical Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Kullervo Hynynen
- Sunnybrook Research Institute, Toronto, ON, Canada.,Department of Medical Biophysics and Institute of Biomaterials & Biomedical Engineering (IBBME), University of Toronto, Toronto, ON, Canada
| | - Nir Lipsman
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, ON, Canada. .,Sunnybrook Research Institute, Hurvitz Brain Sciences Program, Harquail Centre for Neuromodulation, Toronto, ON, Canada. .,Institute of Medical Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
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15
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McDannold N, White PJ, Cosgrove R. Predicting Bone Marrow Damage in the Skull After Clinical Transcranial MRI-Guided Focused Ultrasound With Acoustic and Thermal Simulations. IEEE TRANSACTIONS ON MEDICAL IMAGING 2020; 39:3231-3239. [PMID: 32324544 PMCID: PMC7529866 DOI: 10.1109/tmi.2020.2989121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Transcranial MRI-guided focused ultrasound (TcMRgFUS) thermal ablation is a noninvasive functional neurosurgery technique. Previous reports have shown that damage in the skull bone marrow can occur at high acoustic energies. While this damage is asymptomatic, it would be desirable to avoid it. Here we examined whether acoustic and thermal simulations can predict where the thermal lesions in the marrow occurred. Post-treatment imaging was obtained at 3-15 months after 40 clinical TcMRgFUS procedures, and bone marrow lesions were observed after 16 treatments. The presence of lesions was predicted by the acoustic energy with a threshold of 18.1-21.1 kJ (maximum acoustic energy used) and 97-112 kJ (total acoustic energy applied over the whole treatment). The size of the lesions was not always predicted by the acoustic energy used during treatment alone. In contrast, the locations, sizes, and shapes of the heated regions estimated by the acoustic and thermal simulations were qualitatively similar to those of the lesions. The lesions generally appeared in areas that were predicted to have high temperatures. While more work is needed to validate the temperature estimates in and around the skull, being able to predict the locations and onset for lesions in the bone marrow could allow for better distribution of the acoustic energy over the skull. Understanding skull absorption characteristics of TcMRgFUS could also be useful in optimizing transcranial focusing.
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16
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Jones RM, Huang Y, Meng Y, Scantlebury N, Schwartz ML, Lipsman N, Hynynen K. Echo-Focusing in Transcranial Focused Ultrasound Thalamotomy for Essential Tremor: A Feasibility Study. Mov Disord 2020; 35:2327-2333. [PMID: 32815611 DOI: 10.1002/mds.28226] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 06/30/2020] [Accepted: 07/02/2020] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Transcranial magnetic resonance-guided focused ultrasound (TcMRgFUS) systems currently employ computed tomography (CT)-based aberration corrections, which may provide suboptimal trans-skull focusing. OBJECTIVES The objective of this study was to evaluate a contrast agent microbubble imaging-based transcranial focusing method, echo-focusing (EF), during TcMRgFUS for essential tremor. METHODS A clinical trial of TcMRgFUS thalamotomy using EF for the treatment of essential tremor was conducted (NCT03935581; funded by InSightec [Tirat Carmel, Israel]). Patients (n = 12) were injected with Definity (Lantheus Medical Imaging, North Billerica, MA) microbubbles, and EF was performed using a research feature add-on to a commercial TcMRgFUS system (ExAblate Neuro, InSightec). Subablative thermal sonications carried out using (1) EF and (2) CT-based aberration corrections were compared via magnetic resonance thermometry, and the optimal focusing method for each patient was employed for TcMRgFUS thalamotomy. RESULTS EF aberration corrections provided increased sonication efficiency, decreased focal size, and equivalent targeting accuracy relative to CT-based focusing. EF aberration corrections were employed successfully for lesion formation in all 12 patients, 3 of whom had previously undergone unsuccessful TcMRgFUS thalamotomy via CT-based focusing. There were no adverse events related directly to the EF procedure. CONCLUSIONS EF is feasible and appears safe during TcMRgFUS thalamotomy for essential tremor and improves on the trans-skull focal quality provided by existing CT-based focusing methods. © 2020 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Ryan M Jones
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Yuexi Huang
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Ying Meng
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Nadia Scantlebury
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | - Michael L Schwartz
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Nir Lipsman
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Kullervo Hynynen
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
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17
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Jin C, Moore D, Snell J, Paeng DG. An open-source phase correction toolkit for transcranial focused ultrasound. BMC Biomed Eng 2020; 2:9. [PMID: 32903384 PMCID: PMC7427913 DOI: 10.1186/s42490-020-00043-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 08/03/2020] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND The phase correction on transcranial focused ultrasound is essential to regulate unwanted focal point shift caused by skull bone aberration. The aim of the current study was to design and investigate the feasibility of a ray-based phase correction toolkit for transcranial focused ultrasound. RESULTS The peak pressure at focal area was improved by 140.5 ± 7.0% on target I and 134.8 ± 19.1% on target II using proposed phase correction toolkit, respectively. A total computation time of 402.1 ± 24.5 milliseconds was achieved for each sonication. CONCLUSION The designed ray-based phase correction software can be used as a lightweight toolkit to compensate aberrated phase within clinical environment.
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Affiliation(s)
- Changzhu Jin
- Department of Robotics Engineering, DGIST, Daegu, 42988 Korea
- DGIST-ETH Microrobot Research Center, DGIST, Daegu, 42988 Korea
| | - David Moore
- Focused Ultrasound Foundation, Charlottesville, VA 22903 USA
| | - John Snell
- Focused Ultrasound Foundation, Charlottesville, VA 22903 USA
| | - Dong-Guk Paeng
- Focused Ultrasound Foundation, Charlottesville, VA 22903 USA
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA 22903 USA
- Ocean System, Engineering/ Biomedical Engineering, Jeju National University, Jeju, 63243 Korea
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18
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Jones RM, Kamps S, Huang Y, Scantlebury N, Lipsman N, Schwartz ML, Hynynen K. Accumulated thermal dose in MRI-guided focused ultrasound for essential tremor: repeated sonications with low focal temperatures. J Neurosurg 2020; 132:1802-1809. [PMID: 31075781 PMCID: PMC7139920 DOI: 10.3171/2019.2.jns182995] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 02/22/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The object of this study was to correlate lesion size with accumulated thermal dose (ATD) in transcranial MRI-guided focused ultrasound (MRgFUS) treatments of essential tremor with focal temperatures limited to 50°C-54°C. METHODS Seventy-five patients with medically refractory essential tremor underwent MRgFUS thalamotomy at the authors' institution. Intraoperative MR thermometry was performed to measure the induced temperature and thermal dose distributions (proton resonance frequency shift coefficient = -0.00909 ppm/°C). In 19 patients, it was not possible to raise the focal temperature above 54°C because of unfavorable skull characteristics and/or the pain associated with cranial heating. In this patient subset, sonications with focal temperatures between 50°C and 54°C were repeated (5.1 ± 1.5, mean ± standard deviation) to accumulate a sufficient thermal dose for lesion formation. The ATD profile sizes (17, 40, 100, 200, and 240 cumulative equivalent minutes at 43°C [CEM43]) calculated by combining axial MR thermometry data from individual sonications were correlated with the corresponding lesion sizes measured on axial T1-weighted (T1w) and T2-weighted (T2w) MR images acquired 1 day posttreatment. Manual corrections were applied to the MR thermometry data prior to thermal dose accumulation to compensate for off-resonance-induced spatial-shifting artifacts. RESULTS Mean lesion sizes measured on T2w MRI (5.0 ± 1.4 mm) were, on average, 28% larger than those measured on T1w MRI (3.9 ± 1.4 mm). The ATD thresholds found to provide the best correlation with lesion sizes measured on T2w and T1w MRI were 100 CEM43 (regression slope = 0.97, R2 = 0.66) and 200 CEM43 (regression slope = 0.98, R2 = 0.89), respectively, consistent with data from a previous study of MRgFUS thalamotomy via repeated sonications at higher focal temperatures (≥ 55°C). Two-way linear mixed-effects analysis revealed that dominant tremor subscores on the Fahn-Tolosa-Marin Clinical Rating Scale for Tremor (CRST) were statistically different from baseline at 3 months and 1 year posttreatment in both low-temperature (50°C-54°C) and high-temperature (≥ 55°C) patient cohorts. No significant fixed effect on the dominant tremor scores was found for the temperature cohort factor. CONCLUSIONS In transcranial MRgFUS thalamotomy for essential tremor, repeated sonications with focal temperatures between 50°C and 54°C can accumulate a sufficient thermal dose to generate lesions for clinically relevant tremor suppression up to 1 year posttreatment, and the ATD can be used to predict the size of the resulting ablation zones measured on MRI. These data will serve to guide future clinical MRgFUS brain procedures, particularly those in which focal temperatures are limited to below 55°C.
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Affiliation(s)
- Ryan M. Jones
- Physical Sciences Platform, Sunnybrook Research Institute, University of Toronto, Ontario, Canada
| | - Shona Kamps
- Physical Sciences Platform, Sunnybrook Research Institute, University of Toronto, Ontario, Canada
| | - Yuexi Huang
- Physical Sciences Platform, Sunnybrook Research Institute, University of Toronto, Ontario, Canada
| | - Nadia Scantlebury
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, University of Toronto, Ontario, Canada
| | - Nir Lipsman
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, University of Toronto, Ontario, Canada
- Department of Surgery, University of Toronto, Ontario, Canada
| | - Michael L. Schwartz
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, University of Toronto, Ontario, Canada
- Department of Surgery, University of Toronto, Ontario, Canada
| | - Kullervo Hynynen
- Physical Sciences Platform, Sunnybrook Research Institute, University of Toronto, Ontario, Canada
- Department of Medical Biophysics, University of Toronto, Ontario, Canada
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Ontario, Canada
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19
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Jones RM, McMahon D, Hynynen K. Ultrafast three-dimensional microbubble imaging in vivo predicts tissue damage volume distributions during nonthermal brain ablation. Theranostics 2020; 10:7211-7230. [PMID: 32641988 PMCID: PMC7330857 DOI: 10.7150/thno.47281] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 05/22/2020] [Indexed: 12/13/2022] Open
Abstract
Transcranial magnetic resonance imaging (MRI)-guided focused ultrasound (FUS) thermal ablation is under clinical investigation for non-invasive neurosurgery, though its use is restricted to central brain targets due primarily to skull heating effects. The combination of FUS and contrast agent microbubbles greatly reduces the ultrasound exposure levels needed to ablate brain tissue and may help facilitate the use of transcranial FUS ablation throughout the brain. However, sources of variability exist during microbubble-mediated FUS procedures that necessitate the continued development of systems and methods for online treatment monitoring and control, to ensure that excessive and/or off-target bioeffects are not induced from the exposures. Methods: Megahertz-rate three-dimensional (3D) microbubble imaging in vivo was performed during nonthermal ablation in rabbit brain using a clinical-scale prototype transmit/receive hemispherical phased array system. Results:In-vivo volumetric acoustic imaging over microsecond timescales uncovered spatiotemporal microbubble dynamics hidden by conventional whole-burst temporal averaging. Sonication-aggregate ultrafast 3D source field intensity data were predictive of microbubble-mediated tissue damage volume distributions measured post-treatment using MRI and confirmed via histopathology. Temporal under-sampling of acoustic emissions, which is common practice in the field, was found to impede performance and highlighted the importance of capturing adequate data for treatment monitoring and control purposes. Conclusion: The predictive capability of ultrafast 3D microbubble imaging, reported here for the first time, will enable future microbubble-mediated FUS treatments with unparalleled precision and accuracy, and will accelerate the clinical translation of nonthermal tissue ablation procedures both in the brain and throughout the body.
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Affiliation(s)
- Ryan M. Jones
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Dallan McMahon
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Kullervo Hynynen
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
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20
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Boutet A, Gwun D, Gramer R, Ranjan M, Elias GJB, Tilden D, Huang Y, Li SX, Davidson B, Lu H, Tyrrell P, Jones RM, Fasano A, Hynynen K, Kucharczyk W, Schwartz ML, Lozano AM. The relevance of skull density ratio in selecting candidates for transcranial MR-guided focused ultrasound. J Neurosurg 2020; 132:1785-1791. [PMID: 31051458 DOI: 10.3171/2019.2.jns182571] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 02/05/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Transcranial MR-guided focused ultrasound (MRgFUS) is a minimally invasive treatment for movement disorders. Considerable interpatient variability in skull transmission efficiency exists with the current clinical devices, which is thought to be dependent on each patient's specific skull morphology. Lower skull density ratio (SDR) values are thought to impede acoustic energy transmission across the skull, attenuating or preventing the therapeutic benefits of MRgFUS. Patients with SDR values below 0.4 have traditionally been deemed poor candidates for MRgFUS. Although considerable anecdotal evidence has suggested that SDR is a reliable determinant of procedural and clinical success, relationships between SDR and clinical outcomes have yet to be formally investigated. Moreover, as transcranial MRgFUS is becoming an increasingly widespread procedure, knowledge of SDR distribution in the general population may enable improved preoperative counseling and preparedness. METHODS A total of 98 patients who underwent MRgFUS thalamotomy at the authors' institutions between 2012 and 2018 were analyzed (cohort 1). The authors retrospectively assessed the relationships between SDR and various clinical outcomes, including tremor improvement and adverse effects, as well as procedural factors such as sonication parameters. An SDR was also prospectively obtained in 163 random emergency department patients who required a head CT scan for various clinical indications (cohort 2). Patients' age and sex were used to explore relationships with SDR. RESULTS In the MRgFUS treatment group, 17 patients with a thalamotomy lesion had an SDR below 0.4. Patients with lower SDRs required more sonication energy; however, their low SDR did not influence their clinical outcomes. In the emergency department patient group, about one-third of the patients had a low SDR (< 0.4). SDR did not correlate with age or sex. CONCLUSIONS Although lower SDR values correlated with higher energy requirements during MRgFUS thalamotomy, within the range of this study population, the SDR did not appreciably impact or provide the ability to predict the resulting clinical outcomes. Sampling of the general population suggests that age and sex have no relationship with SDR. Other variables, such as local variances in bone density, should also be carefully reviewed to build a comprehensive appraisal of a patient's suitability for MRgFUS treatment.
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Affiliation(s)
- Alexandre Boutet
- 1University Health Network, Toronto
- 6Joint Department of Medical Imaging, University of Toronto
| | | | | | | | | | | | - Yuexi Huang
- 4Physical Sciences Platform, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto
| | | | | | - Hua Lu
- 6Joint Department of Medical Imaging, University of Toronto
| | - Pascal Tyrrell
- 5Department of Statistical Sciences, University of Toronto
- 6Joint Department of Medical Imaging, University of Toronto
| | - Ryan M Jones
- 4Physical Sciences Platform, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto
| | - Alfonso Fasano
- 2Krembil Research Institute, Toronto
- 7Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto
| | - Kullervo Hynynen
- 4Physical Sciences Platform, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto
- 8Department of Medical Biophysics, University of Toronto
- 9Institute of Biomaterials and Biomedical Engineering, University of Toronto
| | - Walter Kucharczyk
- 1University Health Network, Toronto
- 6Joint Department of Medical Imaging, University of Toronto
| | - Michael L Schwartz
- 10Division of Neurosurgery, Sunnybrook Health Sciences Center, University of Toronto, Ontario, Canada; and
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21
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D'Souza M, Chen KS, Rosenberg J, Elias WJ, Eisenberg HM, Gwinn R, Taira T, Chang JW, Lipsman N, Krishna V, Igase K, Yamada K, Kishima H, Cosgrove R, Rumià J, Kaplitt MG, Hirabayashi H, Nandi D, Henderson JM, Butts Pauly K, Dayan M, Halpern CH, Ghanouni P. Impact of skull density ratio on efficacy and safety of magnetic resonance-guided focused ultrasound treatment of essential tremor. J Neurosurg 2020; 132:1392-1397. [PMID: 31026836 DOI: 10.3171/2019.2.jns183517] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 02/15/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Skull density ratio (SDR) assesses the transparency of the skull to ultrasound. Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy in essential tremor (ET) patients with a lower SDR may be less effective, and the risk for complications may be increased. To address these questions, the authors analyzed clinical outcomes of MRgFUS thalamotomy based on SDRs. METHODS In 189 patients, 3 outcomes were correlated with SDRs. Efficacy was based on improvement in Clinical Rating Scale for Tremor (CRST) scores 1 year after MRgFUS. Procedural efficiency was determined by the ease of achieving a peak voxel temperature of 54°C. Safety was based on the rate of the most severe procedure-related adverse event. SDRs were categorized at thresholds of 0.45 and 0.40, selected based on published criteria. RESULTS Of 189 patients, 53 (28%) had an SDR < 0.45 and 20 (11%) had an SDR < 0.40. There was no significant difference in improvement in CRST scores between those with an SDR ≥ 0.45 (58% ± 24%), 0.40 ≤ SDR < 0.45 (i.e., SDR ≥ 0.40 but < 0.45) (63% ± 27%), and SDR < 0.40 (49% ± 28%; p = 0.0744). Target temperature was achieved more often in those with an SDR ≥ 0.45 (p < 0.001). Rates of adverse events were lower in the groups with an SDR < 0.45 (p = 0.013), with no severe adverse events in these groups. CONCLUSIONS MRgFUS treatment of ET can be effectively and safely performed in patients with an SDR < 0.45 and an SDR < 0.40, although the procedure is more efficient when SDR ≥ 0.45.
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Affiliation(s)
| | | | - Jarrett Rosenberg
- 2Radiology, Stanford University School of Medicine, Stanford, California
| | - W Jeffrey Elias
- 3Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia
| | | | - Ryder Gwinn
- 5Swedish Neuroscience Institute, Seattle, Washington
| | | | - Jin Woo Chang
- 7Yonsei University College of Medicine, Seoul, Korea
| | - Nir Lipsman
- 8Sunnybrook Health Sciences Center, Toronto, Ontario, Canada
| | - Vibhor Krishna
- 9The Ohio State University Medical Center, Columbus, Ohio
| | - Keiji Igase
- 10Washoukai Sadamoto Hospital, Matsuyama City, Japan
| | | | | | - Rees Cosgrove
- 13Brigham and Women's Hospital, Boston, Massachusetts
| | | | | | | | | | | | - Kim Butts Pauly
- 2Radiology, Stanford University School of Medicine, Stanford, California
| | | | | | - Pejman Ghanouni
- 2Radiology, Stanford University School of Medicine, Stanford, California
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22
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Anesthesia considerations of magnetic resonance imaging-guided focused ultrasound thalamotomy for essential tremor: a case series. Can J Anaesth 2020; 67:877-884. [PMID: 32291631 DOI: 10.1007/s12630-020-01644-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 01/29/2020] [Accepted: 01/30/2020] [Indexed: 10/24/2022] Open
Abstract
PURPOSE Essential tremor (ET) is a common movement disorder with disability in voluntary actions such as eating and writing. First-line treatment involves pharmacological agents, although efficacy is limited by side effects. In these patients, functional neurosurgery can be considered. Magnetic resonance imaging-guided focused ultrasound (MRgFUS) thalamotomy offers a non-invasive solution for treatment. This paper examines an original cohort of ET patients undergoing MRgFUS thalamotomy and discusses the anesthetic management of these cases. METHODS We retrospectively reviewed the anesthetic records of all MRgFUS thalamotomy cases from 15 May 2012 to 16 July 2015 at our centre (Sunnybrook Health Sciences Centre, Toronto, Canada) to expand a data set provided by the focused ultrasound system manufacturer (Insightec, Tirat Carmel, Israel) from a prior phase-II regulatory approval study. Specific drug and procedural details were listed including aspects of the patients' experience. RESULTS A total of 82 patients were included in the analysis, 78 from a phase-II trial (16 were from the local site) and four local non-trial cases. No patient required general anesthesia and only 29% of cases required sedation to tolerate the procedure. The most frequent medications required were antiemetics and analgesics. Headache (31%) was the most frequent perioperative symptom. Transient intra-procedural paresthesia symptoms were a common occurrence (32%). CONCLUSIONS The use of MRgFUS for thalamotomy provides a non-invasive and well-tolerated method for treating ET, which usually only requires monitored anesthesia care sedation. Nevertheless, there are several predictable side effects that require contingency planning including the personnel and means to resolve them.
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23
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Deng L, Hughes A, Hynynen K. A Noninvasive Ultrasound Resonance Method for Detecting Skull Induced Phase Shifts May Provide a Signal for Adaptive Focusing. IEEE Trans Biomed Eng 2020; 67:2628-2637. [PMID: 31976875 DOI: 10.1109/tbme.2020.2967033] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE There may be a need to perform dynamic skull aberration corrections during the non-invasive high-intensity transcranial treatment with magnetic resonance imaging (MRI) -guided focused ultrasound in order to accurately and rapidly restore the focus in the brain. METHODS This could possibly be accomplished by using an ultrasound-based correction method based on the skulls' thickness resonance frequencies. The focus of a 500 kHz transducer was centered in the ex vivo human skull caps at different temperatures. The pulse-echoed signals reflected from the skulls were analyzed in the frequency domain to reveal the resonance frequencies for the phase shift calculation. The accuracy was compared to both hydrophone and computed tomography (CT) based analytical methods. RESULTS Around 73% of the measurements (n = 784) were in the optimal constructive interference region, with a 15° decrease in the average phase error compared to the previous study. In the best implementation, it performed approximately the same or better than the CT based analytical method currently in clinical use. Linear correlation was found between the resonance frequencies or skull induced phase shifts and the skull temperature with an average rate of -0.4 kHz/°C and 2.6 deg/°C, respectively. CONCLUSION The ultrasound based resonance method has shown the feasibility of detecting heating-induced changes of skull phase shift non-invasively and accurately. SIGNIFICANCE Since the technique can be made MRI compatible and integrated in the therapy arrays, it may enable temperature tracking and adaptive focusing during high-intensity transcranial ultrasound treatments, to prevent skull overheating and preserve the transcranial focusing integrity.
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24
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McDannold N, White PJ, Cosgrove R. Elementwise approach for simulating transcranial MRI-guided focused ultrasound thermal ablation. PHYSICAL REVIEW RESEARCH 2019; 1:033205. [PMID: 34164625 PMCID: PMC8218657 DOI: 10.1103/physrevresearch.1.033205] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
This work explored an elementwise approach to model transcranial MRI-guided focused ultrasound (TcMRgFUS) thermal ablation, a noninvasive approach to neurosurgery. Each element of the phased array transducer was simulated individually and could be simultaneously loaded into computer memory, allowing for rapid (~2.5 s) calculation of the pressure field for different phase offsets used for beam steering and aberration correction. We simulated the pressure distribution for 431 sonications in 32 patients, applied the phase and magnitude values used during treatment, and estimated the resulting temperature rise. We systematically varied the relationship between CT (computerized tomography)-derived skull density and the acoustic attenuation and sound speed to obtain the best agreement between the predictions and MR temperature imaging (MRTI). The optimization was validated with simulations of 396 sonications from 40 additional treatments. After optimization, the predicted and measured heating agreed well (R 2: 0.74 patients 1-32; 0.71 patients 33-72). The dimensions and obliquity of the heating in the simulated temperature maps were correlated with the MRTI (R 2: 0.62, 0.74, respectively), but the measured heating was more spatially diffuse. The energy needed to achieve ablation varied by an order of magnitude (3.3-36.1 kJ). While this elementwise approach required more computation time up front (the combined simulation matrices were approximately 4.6 times higher than a single large simulation), it could be performed in parallel on a computing cluster. It allows for rapid calculation of the three-dimensional heating at the focus for different phase and magnitude values on the array. We also show how this approach can be used to optimize the relationship between CT-derived skull density and acoustic properties. While the relationships found here need further validation in a larger patient population, these results demonstrate the promise of this approach to model TcMRgFUS.
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Affiliation(s)
- Nathan McDannold
- Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - P Jason White
- Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Rees Cosgrove
- Department of Neurosurgery, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
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25
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Considerations for ultrasound exposure during transcranial MR acoustic radiation force imaging. Sci Rep 2019; 9:16235. [PMID: 31700021 PMCID: PMC6838326 DOI: 10.1038/s41598-019-52443-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 10/15/2019] [Indexed: 12/15/2022] Open
Abstract
The aim of this study was to improve the sensitivity of magnetic resonance-acoustic radiation force imaging (MR-ARFI) to minimize pressures required to localize focused ultrasound (FUS) beams, and to establish safe FUS localization parameters for ongoing ultrasound neuromodulation experiments in living non-human primates. We developed an optical tracking method to ensure that the MR-ARFI motion-encoding gradients (MEGs) were aligned with a single-element FUS transducer and that the imaged slice was prescribed at the optically tracked location of the acoustic focus. This method was validated in phantoms, which showed that MR-ARFI-derived displacement sensitivity is maximized when the MR-ARFI MEGs were maximally aligned with the FUS propagation direction. The method was then applied in vivo to acquire displacement images in two healthy macaque monkeys (M fascicularis) which showed the FUS beam within the brain. Temperature images were acquired using MR thermometry to provide an estimate of in vivo brain temperature changes during MR-ARFI, and pressure and thermal simulations of the acoustic pulses were performed using the k-Wave package which showed no significant heating at the focus of the FUS beam. The methods presented here will benefit the multitude of transcranial FUS applications as well as future human applications.
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26
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Chang KW, Park YS, Chang JW. Skull Factors Affecting Outcomes of Magnetic Resonance-Guided Focused Ultrasound for Patients with Essential Tremor. Yonsei Med J 2019; 60:768-773. [PMID: 31347332 PMCID: PMC6660436 DOI: 10.3349/ymj.2019.60.8.768] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 05/03/2019] [Accepted: 05/29/2019] [Indexed: 11/27/2022] Open
Abstract
PURPOSE Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy has become a standard treatment for medically intractable essential tremor (ET). Skull density ratio (SDR) and skull volume in patients with ET are currently considered useful indicators of the successful application of MRgFUS. We compared the clinical outcomes of MRgFUS thalamotomy with SDR above 0.4 and 0.45. We also described patterns of SDR and skull volume in Korean patients with ET who were eligible to be screened for MRgFUS. MATERIALS AND METHODS In screening 318 ET patients, we evaluated patterns of skull density and skull volume according to age and sex. Fifty patients with ET were treated with MRgFUS. We investigated the effects of SDR and skull volume on treatment parameters and the outcomes of ET. RESULTS The mean SDR of the 318 ET patients was 0.45±0.11, and that for skull volume was 315.74±40.95 cm³. The male patients had a higher SDR than female patients (p=0.047). Skull volume significantly decreased with aging. SDR and skull volume exhibited a linear negative relationship. Among therapeutic parameters, maximal temperature was positively related to SDR, while sonication number was not related to either SDR or skull volume. Tremor outcome was also not related to SDR or skull volume. CONCLUSION SDR varied widely from 0.11 to 0.73, and men had a higher SDR. Therapeutic parameters and clinical outcomes were not affected by SDR or skull volume.
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Affiliation(s)
- Kyung Won Chang
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Yong Sook Park
- Department of Neurosurgery, Brain Research Institute, Chung-Ang University College of Medicine, Seoul, Korea
| | - Jin Woo Chang
- Department of Neurosurgery, Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
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27
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Jones RM, Hynynen K. Advances in acoustic monitoring and control of focused ultrasound-mediated increases in blood-brain barrier permeability. Br J Radiol 2019; 92:20180601. [PMID: 30507302 DOI: 10.1259/bjr.20180601] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Transcranial focused ultrasound (FUS) combined with intravenously circulating microbubbles can transiently and selectively increase blood-brain barrier permeability to enable targeted drug delivery to the central nervous system, and is a technique that has the potential to revolutionize the way neurological diseases are managed in medical practice. Clinical testing of this approach is currently underway in patients with brain tumors, early Alzheimer's disease, and amyotrophic lateral sclerosis. A major challenge that needs to be addressed in order for widespread clinical adoption of FUS-mediated blood-brain barrier permeabilization to occur is the development of systems and methods for real-time treatment monitoring and control, to ensure that safe and effective acoustic exposure levels are maintained throughout the procedures. This review gives a basic overview of the oscillation dynamics, acoustic emissions, and biological effects associated with ultrasound-stimulated microbubbles in vivo, and provides a summary of recent advances in acoustic-based strategies for detecting, controlling, and mapping microbubble activity in the brain. Further development of next-generation clinical FUS brain devices tailored towards microbubble-mediated applications is warranted and required for translation of this potentially disruptive technology into routine clinical practice.
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Affiliation(s)
- Ryan M Jones
- 1 Physical Sciences Platform, Sunnybrook Research Institute , Toronto, ON , Canada
| | - Kullervo Hynynen
- 1 Physical Sciences Platform, Sunnybrook Research Institute , Toronto, ON , Canada.,2 Department of Medical Biophysics, University of Toronto , Toronto, ON , Canada.,3 Institute of Biomaterials and Biomedical Engineering, University of Toronto , Toronto, ON , Canada
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28
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McMahon D, Poon C, Hynynen K. Evaluating the safety profile of focused ultrasound and microbubble-mediated treatments to increase blood-brain barrier permeability. Expert Opin Drug Deliv 2019; 16:129-142. [PMID: 30628455 DOI: 10.1080/17425247.2019.1567490] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
INTRODUCTION Treatment of several diseases of the brain are complicated by the presence of the skull and the blood-brain barrier (BBB). Focused ultrasound (FUS) and microbubble (MB)-mediated BBB treatment is a minimally invasive method to transiently increase the permeability of blood vessels in targeted brain areas. It can be used as a general delivery system to increase the concentration of therapeutic agents in the brain parenchyma. AREAS COVERED Over the past two decades, the safety of using FUS+MBs to deliver agents across the BBB has been interrogated through various methods of imaging, histology, biochemical assays, and behavior analyses. Here we provide an overview of the factors that affect the safety profile of these treatments, describe methods by which FUS+MB treatments are controlled, and discuss data that have informed the assessment of treatment risks. EXPERT OPINION There remains a need to assess the risks associated with clinically relevant treatment strategies, specifically repeated FUS+MB treatments, with and without therapeutic agent delivery. Additionally, efforts to develop metrics by which FUS+MB treatments can be easily compared across studies would facilitate a more rapid consensus on the risks associated with this intervention.
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Affiliation(s)
- Dallan McMahon
- a Physical Sciences Platform , Sunnybrook Research Institute , Toronto , ON , Canada.,b Department of Medical Biophysics , University of Toronto , Toronto , ON , Canada
| | - Charissa Poon
- a Physical Sciences Platform , Sunnybrook Research Institute , Toronto , ON , Canada.,c Institute of Biomaterials and Biomedical Engineering , University of Toronto , Toronto , ON , Canada
| | - Kullervo Hynynen
- a Physical Sciences Platform , Sunnybrook Research Institute , Toronto , ON , Canada.,b Department of Medical Biophysics , University of Toronto , Toronto , ON , Canada.,c Institute of Biomaterials and Biomedical Engineering , University of Toronto , Toronto , ON , Canada
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29
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Fomenko A, Lozano AM. Neuromodulation and ablation with focused ultrasound - toward the future of noninvasive brain therapy. Neural Regen Res 2019; 14:1509-1510. [PMID: 31089042 PMCID: PMC6557107 DOI: 10.4103/1673-5374.255961] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Anton Fomenko
- Krembil Research Institute, University Health Network, Toronto, Canada
| | - Andres M Lozano
- Krembil Research Institute, University Health Network; Division of Neurosurgery, Toronto Western Hospital, Toronto, Canada
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30
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Zafar A, Quadri SA, Farooqui M, Ortega-Gutiérrez S, Hariri OR, Zulfiqar M, Ikram A, Khan MA, Suriya SS, Nunez-Gonzalez JR, Posse S, Mortazavi MM, Yonas H. MRI-Guided High-Intensity Focused Ultrasound as an Emerging Therapy for Stroke: A Review. J Neuroimaging 2018; 29:5-13. [PMID: 30295987 DOI: 10.1111/jon.12568] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 09/21/2018] [Indexed: 01/23/2023] Open
Abstract
Stroke, either ischemic or hemorrhagic, accounts for significantly high morbidity and mortality rates around the globe effecting millions of lives annually. For the past few decades, ultrasound has been extensively investigated to promote clot lysis for the treatment of stroke, myocardial infarction, and acute peripheral arterial occlusions, with or without the use of tPA or contrast agents. In the age of modern minimal invasive techniques, magnetic resonance imaging-guided high-intensity focused ultrasound is a new emerging modality that seems to promise therapeutic utilities for both ischemic and hemorrhagic stroke. High-intensity focused ultrasound causes thermal heating as the tissue absorbs the mechanical energy transmitted by the ultrasonic waves leading to tissue denaturation and coagulation. Several in-vitro and in-vivo studies have demonstrated the viability of this technology for sonothrombolysis in both types of stroke and have warranted clinical trials. Apart from safety and efficacy, initiation of trials would further enable answers regarding its practical application in a clinical setup. Though this technology has been under study for treatment of various brain diseases for some decades now, relatively very few neurologists and even neurosurgeons seem to be acquainted with it. The aim of this review is to provide basic understanding of this powerful technology and discuss its clinical application and potential role as an emerging viable therapeutic option for the future management of stroke.
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Affiliation(s)
- Atif Zafar
- Department of Neurology, University of New Mexico Hospitals, Albuquerque, NM
| | - Syed A Quadri
- Department of Neurology, University of New Mexico Hospitals, Albuquerque, NM.,California Institute of Neuroscience, Thousand Oaks, CA.,National Skull Base Center, Thousand Oaks, CA
| | - Mudassir Farooqui
- Department of Neurology, University of New Mexico Hospitals, Albuquerque, NM
| | | | - Omid R Hariri
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA
| | - Maryam Zulfiqar
- Department of Neurology, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Asad Ikram
- Department of Neurology, University of New Mexico Hospitals, Albuquerque, NM
| | - Muhammad Adnan Khan
- Department of Neurology, University of New Mexico Hospitals, Albuquerque, NM.,California Institute of Neuroscience, Thousand Oaks, CA.,National Skull Base Center, Thousand Oaks, CA
| | - Sajid S Suriya
- Department of Neurology, University of New Mexico Hospitals, Albuquerque, NM.,California Institute of Neuroscience, Thousand Oaks, CA.,National Skull Base Center, Thousand Oaks, CA
| | | | - Stefan Posse
- Department of Neurology, University of New Mexico Hospitals, Albuquerque, NM
| | - Martin M Mortazavi
- California Institute of Neuroscience, Thousand Oaks, CA.,National Skull Base Center, Thousand Oaks, CA
| | - Howard Yonas
- Department of Neurosurgery, University of New Mexico, Albuquerque, NM
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31
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Levi Chazen J, Stradford T, Kaplitt MG. Cranial MR-guided Focused Ultrasound for Essential Tremor. Clin Neuroradiol 2018; 29:351-357. [DOI: 10.1007/s00062-018-0709-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 07/06/2018] [Indexed: 11/28/2022]
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32
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Hughes A, Huang Y, Schwartz ML, Hynynen K. The reduction in treatment efficiency at high acoustic powers during MR-guided transcranial focused ultrasound thalamotomy for Essential Tremor. Med Phys 2018; 45:2925-2936. [PMID: 29758099 DOI: 10.1002/mp.12975] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 05/07/2018] [Accepted: 05/07/2018] [Indexed: 12/19/2022] Open
Abstract
PURPOSE To analyze clinical data indicating a reduction in the induced energy-temperature efficiency relationship during transcranial focused ultrasound (FUS) Essential Tremor (ET) thalamotomy treatments at higher acoustic powers, establish its relationship with the spatial distribution of the focal temperature elevation, and explore its cause. METHODS A retrospective observational study of patients (n = 19) treated between July 2015 and August 2016 for (ET) by FUS thalamotomy was performed. These data were analyzed to compare the relationships between the applied power, the applied energy, the resultant peak temperature achieved in the brain, and the dispersion of the focal volume. Full ethics approval was received and all patients provided signed informed consent forms before the initiation of the study. Computer simulations, animal experiments, and clinical system tests were performed to determine the effects of skull heating, changes in brain properties and transducer acoustic output, respectively. All animal procedures were approved by the Animal Care and Use Committee and conformed to the guidelines set out by the Canadian Council on Animal Care. MATLAB was used to perform statistical analysis. RESULTS The reduction in the energy efficiency relationship during treatment correlates with the increase in size of the focal volume at higher sonication powers. A linear relationship exists showing that a decrease in treatment efficiency correlates positively with an increase in the focal size over the course of treatment (P < 0.01), supporting the hypothesis of transient skull and tissue heating causing acoustic aberrations leading to a decrease in efficiency. Changes in thermal conductivity, perfusion, absorption rates in the brain, as well as ultrasound transducer acoustic output levels were found to have minimal effects on the observed reduction in efficiency. CONCLUSIONS The reduction in energy-temperature efficiency during high-power FUS treatments correlated with observed increases in the size of the focal volume and is likely caused by transient changes in the tissue and skull during heating.
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Affiliation(s)
- Alec Hughes
- Department of Medical Biophysics, University of Toronto, 101 College St, Room 15-701, Toronto, Canada.,Physical Sciences Platform, Sunnybrook Research Institute, Room C713, 2075 Bayview Ave, Toronto, Canada
| | - Yuexi Huang
- Physical Sciences Platform, Sunnybrook Research Institute, Room C713, 2075 Bayview Ave, Toronto, Canada
| | - Michael L Schwartz
- Division of Neurosurgery, Department of Surgery, Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Kullervo Hynynen
- Department of Medical Biophysics, University of Toronto, 101 College St, Room 15-701, Toronto, Canada.,Physical Sciences Platform, Sunnybrook Research Institute, Room C713, 2075 Bayview Ave, Toronto, Canada
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