Transcranial magnetic resonance imaging–guided focused ultrasound thalamotomy for tremor: technical note

Wang, Tony R.; Bond, A.E.; Dallapiazza, Robert F.; Blanke, Aaron; Tilden, David; Huerta, Thomas E.; Moosa, Shayan; Prada, Francesco; Elias, W. Jeffrey

doi:10.3171/2017.10.focus17609

Cited by 40 publications

(41 citation statements)

References 29 publications

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“…In this review, we tried to summarize the different biological mechanisms offered by focused ultrasound pertinent to neurooncological and vascular diseases: with the promising results associated with the use of FUS for essential tremor [130], although first tested in brain tumors, more groups are likely to begin clinical studies for other disease states, as the number of ongoing preclinical researches and clinical application is steadily increasing.…”

Section: Resultsmentioning

confidence: 99%

Applications of Focused Ultrasound in Cerebrovascular Diseases and Brain Tumors

et al. 2019

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Oncology and cerebrovascular disease constitute two of the most common diseases afflicting the central nervous system. Standard of treatment of these pathologies is based on multidisciplinary approaches encompassing combination of interventional procedures such as open and endovascular surgeries, drugs (chemotherapies, anti-coagulants, anti-platelet therapies, thrombolytics), and radiation therapies. In this context, therapeutic ultrasound could represent a novel diagnostic/therapeutic in the armamentarium of the surgeon to treat these diseases. Ultrasound relies on mechanical energy to induce numerous physical and biological effects. The application of this technology in neurology has been limited due to the challenges with penetrating the skull, thus limiting a prompt translation as has been seen in treating pathologies in other organs, such as breast and abdomen. Thanks to pivotal adjuncts such as multiconvergent transducers, magnetic resonance imaging (MRI) guidance, MRI thermometry, implantable transducers, and acoustic windows, focused ultrasound (FUS) is ready for prime-time applications in oncology and cerebrovascular neurology. In this review, we analyze the evolution of FUS from the beginning in 1950s to current state-of-the-art. We provide an overall picture of actual and future applications of FUS in oncology and cerebrovascular neurology reporting for each application the principal existing evidences.

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Section: Resultsmentioning

confidence: 99%

Applications of Focused Ultrasound in Cerebrovascular Diseases and Brain Tumors

et al. 2019

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“…Detailed descriptions of tcMRgFUS thalamotomy have been extensively described in prior reports [ 7 , 15 ]. Briefly, before the procedure, the patient’s head was comparatively shaved and immobilized to the FUS helmet using a stereotactic frame.…”

Section: Methodsmentioning

confidence: 99%

Transcranial Magnetic Resonance Imaging-Guided Focused Ultrasound with a 1.5 Tesla Scanner: A Prospective Intraindividual Comparison Study of Intraoperative Imaging

et al. 2021

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Background: High-quality intraoperative imaging is needed for optimal monitoring of patients undergoing transcranial MR-guided Focused Ultrasound (tcMRgFUS) thalamotomy. In this paper, we compare the intraoperative imaging obtained with dedicated FUS-Head coil and standard body radiofrequency coil in tcMRgFUS thalamotomy using 1.5-T MR scanner. Methods: This prospective study included adult patients undergoing tcMRgFUS for treatment of essential tremor. Intraoperative T2-weighted FRFSE sequences were acquired after the last high-energy sonication using a dedicated two-channel FUS-Head (2ch-FUS) coil and body radiofrequency (body-RF) coil. Postoperative follow-ups were performed at 48 h using an eight-channel phased-array (8ch-HEAD) coil. Two readers independently assessed the signal-to-noise ratio (SNR) and evaluated the presence of concentric lesional zones (zone I, II and III). Intraindividual differences in SNR and lesional findings were compared using the Wilcoxon signed rank sum test and McNemar test. Results: Eight patients underwent tcMRgFUS thalamotomy. Intraoperative T2-weighted FRFSE images acquired using the 2ch-FUS coil demonstrated significantly higher SNR (R1 median SNR: 10.54; R2: 9.52) compared to the body-RF coil (R1: 2.96, p < 0.001; R2: 2.99, p < 0.001). The SNR was lower compared to the 48-h follow-up (p < 0.001 for both readers). Intraoperative zone I and zone II were more commonly visualized using the 2ch-FUS coil (R1, p = 0.031 and p = 0.008, R2, p = 0.016, p = 0.008), without significant differences with 48-h follow-up (p ≥ 0.063). The inter-reader agreement was almost perfect for both SNR (ICC: 0.85) and lesional findings (k: 0.82–0.91). Conclusions: In the study population, the dedicated 2ch-FUS coil significantly improved the SNR and visualization of lesional zones on intraoperative imaging during tcMRgFUS performed with a 1.5-T MR scanner.

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“…Magnetic resonance-guided focused ultrasound surgery (MRgFUS) through the human skull is a novel treatment for functional brain disorders. It has been widely applied to treat movement disorders such as essential tremor (ET; Chang et al, 2015 , 2016 , 2019 ; Elias et al, 2016 ; Gallay et al, 2016 ; Chazen et al, 2018 ; Jung et al, 2018 ; Wang et al, 2018 ; Gasca-Salas et al, 2019 ) and Parkinson’s disease (PD; Na et al, 2015 ; Bond et al, 2017 ; Weintraub and Elias, 2017 ; Martinez-Fernandez et al, 2018 ), intractable neuropathic pain, and even neuropsychiatric disorders such as obsessive–compulsive disorder ( Jeanmonod et al, 2012 ; Jung et al, 2015 ; Chang et al, 2016 ; Kim et al, 2018 ). It is a relatively safe procedure with minimal side effects and proven efficacy in various diseases ( Na et al, 2015 ; Bond et al, 2017 ; Chazen et al, 2018 ; Wang et al, 2018 ; Gasca-Salas et al, 2019 ).…”

Section: Introductionmentioning

confidence: 99%

Safety and Efficacy of Magnetic Resonance-Guided Focused Ultrasound Surgery With Autofocusing Echo Imaging

et al. 2021

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ObjectiveMagnetic 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.MethodsFrom 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.ResultsThe 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).ConclusionUsing 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 Registrationclinicaltrials.gov, identifier: NCT03935581.

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Transcranial magnetic resonance imaging–guided focused ultrasound thalamotomy for tremor: technical note

Cited by 40 publications

References 29 publications

Applications of Focused Ultrasound in Cerebrovascular Diseases and Brain Tumors

Applications of Focused Ultrasound in Cerebrovascular Diseases and Brain Tumors

Transcranial Magnetic Resonance Imaging-Guided Focused Ultrasound with a 1.5 Tesla Scanner: A Prospective Intraindividual Comparison Study of Intraoperative Imaging

Safety and Efficacy of Magnetic Resonance-Guided Focused Ultrasound Surgery With Autofocusing Echo Imaging

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