Focused ultrasound

Last updated

Focused ultrasound
Diagram showing liver lesioning using a HIFU transducer 2.png
Diagram showing how HIFU can be used to destroy tissue in the body. An acoustic lens is used to focus sound to a small point in the body. The sound propagates through many layers of tissue. Because of the focal gain, only tissue at the focus is destroyed.
Other namesMagnetic-resonance-guided focused ultrasound surgery (MRgFUS), focused ultrasound surgery (FUS), MR-guided focused ultrasound ablation

High-intensity focused ultrasound (HIFU), or MR-guided focused ultrasound surgery (MR-guided focused ultrasound ablation), is an incisionless therapeutic technique [1] that uses non-ionizing ultrasonic waves to heat or ablate tissue. HIFU can be used to increase the flow of blood or lymph or to destroy tissue, such as tumors, via thermal and mechanical mechanisms. Given the prevalence and relatively low cost of ultrasound generation mechanisms, the premise of HIFU is that it is expected to be a non-invasive and low-cost therapy that can at least outperform care in the operating room.

Contents

The technology is different from that used in ultrasonic imaging, though lower frequencies and continuous, rather than pulsed, waves are used to achieve the necessary thermal doses. However, pulsed waves may also be used if mechanical rather than thermal damage is desired. Acoustic lenses are often used to achieve the necessary intensity at the target tissue without damaging the surrounding tissue. The ideal pattern diagram is the beam-focusing of a magnifying glass of sunlight; only the focal point of the magnifying glass has high temperature.

HIFU is combined with other imaging techniques such as medical ultrasound or MRI to enable guidance of the treatment and monitoring.

History

Studies on localized prostate cancer showed that, after treatment, progression-free survival rates were high for low- and intermediate- risk patients with recurrent prostate cancer. [2] The InsighTec ExAblate 2000 was the first MRgFUS system to obtain FDA market approval, [3] US patent 5,247,935.

Medical uses

There is no clear consensus on the boundaries between HIFU and other forms of therapeutic ultrasound. In particular literature, HIFU refers to the high levels of energy required to destroy tissue through ablation or cavitation, although it is also sometimes used to describe lower intensity applications such as occupational therapy and physical therapy.

Either way, HIFU is used to non-invasively heat tissue deep in the body without the need for an incision. [1] The main applications are the destruction of tissue caused by hyperthermia, increasing perfusion and physical therapy. The use of ultrasound in the treatment of musculoskeletal conditions is another use in the physiotherapy setting. [4]

Neurological disorders

Frontal MRI four days after MRgFUS (MRI-guided high-intensity focused ultrasound): Left ventral intermediate nucleus (Vim) thalamotomy. 79-year-old man with essential tremor. MRI-guided HIFU, essential tremor, 10-14 135, pointed.png
Frontal MRI four days after MRgFUS (MRI-guided high-intensity focused ultrasound): Left ventral intermediate nucleus (Vim) thalamotomy. 79-year-old man with essential tremor.

One of the first applications of HIFU was the treatment of Parkinson's disease in the 1940s. Although ineffective at the time, HIFU has the capacity to lesion pathology. A focused ultrasound system is approved in Israel, Canada, Italy, Korea and Russia to treat essential tremor, [5] neuropathic pain, [6] and Parkinsonian tremor. [7] This approach enables treatment of the brain without an incision or radiation. In 2016, the US Food and Drug Administration ( FDA ) approved Insightec's Exablate system to treat essential tremor. [8] Treatment for other thalamocortical dysrhythmias and psychiatric conditions are under investigation. [9]

Cancers

Prostate

HIFU may be effective for treating prostate cancer. [10] [11] [12]

Liver

HIFU is studied in liver cancer and in many studies report a high response rate and positive outcome. [13] During the treatment of metastasized liver cancer with HIFU, immune responses have been observed in locations that are distant from the focal region. [14]

Prostate enlargement

Treatment of prostate enlargement (benign prostatic hyperplasia) by HIFU from inside the intestine (transrectal) has turned out to be unsuccessful. [15] [16]

In some countries, not in USA, HIFU has also been offered from the inside of the prostate, that is, via a catheter in the prostatic urethra. Evidence as of 2019 is lacking. [17]

In England the National Institute for Health and Care Excellence (NICE) in 2018 classified the method as "not recommended". [18]

Mechanism

HIFU beams are precisely focused on a small region of diseased tissue to locally deposit high levels of energy.

Ideal temperature

The temperature of tissue at the focus will rise to between 65 and 85 °C, destroying the diseased tissue by coagulative necrosis. If tissue is elevated above the threshold of 60 °C for longer than 1 second this process is irreversible. [19] Each sonication (individual ultrasound energy deposition) treats a precisely defined portion of the targeted tissue. The entire therapeutic target is treated by using multiple sonications to create a volume of incompressible material, such as tap water. [20]

with the integral being over the treatment time, R=0.5 for temperatures over 43 °C and 0.25 for temperatures between 43 °C and 37 °C, a reference temperature of 43 °C, and time T is in minutes. The equations and methods described in this report are not intended to represent any clinical result, this is only an approach for thermal dose estimation in a incompressible material of just tap water; . [21]

As an ultrasound acoustic wave cannot propagates through the compressive tissue, such as rubber, human tissues part of it and the ultrasound energy will be turned to converted as heat, with focused beams, a very small region of heating can be achieved the part of shallow deep in tissues (usually on the order of 2~3 millimeters). Tissue occurs as a function of both the subtle shaking to which the water is heated and how long the part of water is exposed to this heat level in a metric referred to as "thermal dose". By focusing at more than one place or by scanning the focus, a volume can be thermally ablated. [22] [23] [24] Thermal doses of 120-240 min at 43 °C coagulate cellular protein and leads to irreversible tissue destruction.

There are some reports that HIFU could be applied to cancers to disrupt the tumor microenvironment and trigger an immune response, as well as possibly enhance the efficacy of immunotherapy. [25] [26]

Mechanical

Inertial cavitation

At high enough acoustic intensities, cavitation (microbubbles forming and interacting with the ultrasound field) can occur. Microbubbles produced in the field oscillate and grow (due to factors including rectified diffusion), and can eventually implode (inertial or transient cavitation). During inertial cavitation, very high temperatures occur inside the bubbles, and the collapse during the rarefaction phase is associated with a shock wave and jets that can mechanically damage tissue. [27]

Stable cavitation

Stable cavitation creates microstreaming which induces high shear forces on cells and leads to apoptosis. Elaborating, bubbles produced by the vaporization of water due to acoustic forces oscillate under a low-pressure acoustic field. Strong streaming may cause cell damage but also reduces tissue temperature via convective heat loss. [28]

Theory

There are several ways to focus ultrasound—via a lens (for example, a polystyrene lens, parabola curve transducer, a phased array, etc. The special patents and very precise technology solve the problem. This can be determined using an exponential model of ultrasound attenuation. The ultrasound intensity profile is bounded by an exponentially decreasing function where the decrease in ultrasound is a function of distance traveled through tissue:

is the initial intensity of the beam, is the attenuation coefficient (in units of inverse length), and z is the distance traveled through the attenuating medium (e.g. tissue).

In this ideal model, [29] is a measure of the power density of the heat absorbed from the ultrasound field. This demonstrates that tissue heating is proportional to intensity, and that intensity is inversely proportional to the area over which an ultrasound beam is spread. Therefore, focusing the beam into a sharp point or increasing the beam intensity creates a rapid temperature rise at the focus.[ citation needed ]

The ultrasound beam can be focused in these ways:

Beam delivery

Beam delivery consists of beam steering and image guidance. The beam has the ability to pass through overlying tissues without harm and focus on a localized area with size limit of 2–3 mm, that is determined the clinical frequency of the ultrasound. Following ablation a distinct boundary forms between healthy and necrotic tissue (width less than 50 microns). [30]

Beam steering

The most common transducer used is a concave focusing transducer with a fixed aperture and a fixed focal length. [30] Phased array transducers can also be used with different arrangements (flat/bowl). [30]

Image guidance

HIFU therapy requires careful monitoring and so it is usually performed in conjunction with other imaging techniques.

Pre-operative imaging, for instance CT and MRI, are usually used to identify general parameters of the target anatomy. Real-time imaging, on the other hand, is necessary for safe and accurate noninvasive targeting and therapy monitoring. Both MRI and Medical ultrasound imaging have been used for guidance in FUS treatment. These techniques are known as Magnetic Resonance guided Focused Ultrasound Surgery (MRgFUS) [31] [32] and Ultrasound guided Focused Ultrasound Surgery (USgFUS) respectively. [1] [33] MRgFUS is a 3D imaging technique which features high soft tissue contrast and provides information about temperature, thus allowing to monitor ablation. However, low frame rate makes this technique perform poorly in real-time imaging and high costs represent a significant limitation to its use. [34] USgFUS, differently, is a 2D imaging technique in which, although no system to provide quantitative information on temperature has been commercially developed so far, several benefits are exploited, such as high frame rate (up to 1000 images per second), low cost and minimal adverse health effects. Another reason why ultrasound is ideal for image guidance is it verifies the acoustic window in real time since it is the same modality as the therapy. [35] The implication of this is that if the target region is not visualized by ultrasound imaging before and during HIFU therapy, then it is unlikely that HIFU therapy will be effective in that specific region. [35] In addition, treatment outcomes can be estimated in real time through visual inspection of hyperechoic changes in standard B-mode images. [36]

Related Research Articles

Ultrasound is sound with frequencies greater than 20 kilohertz. This frequency is the approximate upper audible limit of human hearing in healthy young adults. The physical principles of acoustic waves apply to any frequency range, including ultrasound. Ultrasonic devices operate with frequencies from 20 kHz up to several gigahertz.

<span class="mw-page-title-main">Medical ultrasound</span> Diagnostic and therapeutic technique

Medical ultrasound includes diagnostic techniques using ultrasound, as well as therapeutic applications of ultrasound. In diagnosis, it is used to create an image of internal body structures such as tendons, muscles, joints, blood vessels, and internal organs, to measure some characteristics or to generate an informative audible sound. The usage of ultrasound to produce visual images for medicine is called medical ultrasonography or simply sonography, or echography. The practice of examining pregnant women using ultrasound is called obstetric ultrasonography, and was an early development of clinical ultrasonography. The machine used is called an ultrasound machine, a sonograph or an echograph. The visual image formed using this technique is called an ultrasonogram, a sonogram or an echogram.

<span class="mw-page-title-main">Sonophoresis</span>

Sonophoresis also known as phonophoresis, is a method that utilizes ultrasound to enhance the delivery of topical medications through the stratum corneum, to the epidermis and dermis. Sonophoresis allows for the enhancement of the permeability of the skin along with other modalities, such as iontophoresis, to deliver drugs with lesser side effects. Currently, sonophoresis is used widely in transdermal drug delivery, but has potential applications in other sectors of drug delivery, such as the delivery of drugs to the eye and brain.

<span class="mw-page-title-main">3D ultrasound</span> Rendering technique in medical imaging

3D ultrasound is a medical ultrasound technique, often used in fetal, cardiac, trans-rectal and intra-vascular applications. 3D ultrasound refers specifically to the volume rendering of ultrasound data. When involving a series of 3D volumes collected over time, it can also be referred to as 4D ultrasound or real-time 3D ultrasound.

<span class="mw-page-title-main">Therapeutic ultrasound</span> Medical procedure for pain relief

Therapeutic ultrasound refers generally to the use of ultrasound for the treatment of a medical condition or for therapeutic benefit. Physiotherapeutic ultrasound was introduced into clinical practice in the 1950s, with lithotripsy introduced in the 1980s. Other uses of ultrasound for therapeutic benefit are at various stages in transitioning from research to clinical use and include: high-intensity focused ultrasound (HIFU), targeted ultrasound drug delivery, trans-dermal ultrasound drug delivery, ultrasound hemostasis, cancer therapy, and ultrasound assisted thrombolysis Ultrasound used for therapeutic benefit often use focused ultrasound waves, however, unfocused ultrasound waves may also be used.

Ronald H. Silverman is an American ophthalmologist. He is currently Professor of Ophthalmic Science at Columbia University Medical Center. He is currently the director of the CUMC Basic Science Course in Ophthalmology, which takes place every January at the Harkness Eye Institute. He departed Weill Cornell Medical College in 2010, where he was Professor of Ophthalmology as well as a Dyson Scholar and the Research Director of the Bioacoustic Research Facility, Margaret M. Dyson Vision Research Institute at Weill Cornell.

Ultrasound energy, simply known as ultrasound, is a type of mechanical energy called sound characterized by vibrating or moving particles within a medium. Ultrasound is distinguished by vibrations with a frequency greater than 20,000 Hz, compared to audible sounds that humans typically hear with frequencies between 20 and 20,000 Hz. Ultrasound energy requires matter or a medium with particles to vibrate to conduct or propagate its energy. The energy generally travels through most mediums in the form of a wave in which particles are deformed or displaced by the energy then reestablished after the energy passes. Types of waves include shear, surface, and longitudinal waves with the latter being one of the most common used in biological applications. The characteristics of the traveling ultrasound energy greatly depend on the medium that it is traveling through. While ultrasound waves propagate through a medium, the amplitude of the wave is continually reduced or weakened with the distance it travels. This is known as attenuation and is due to the scattering or deflecting of energy signals as the wave propagates and the conversion of some of the energy to heat energy within the medium. A medium that changes the mechanical energy from the vibrations of the ultrasound energy into thermal or heat energy is called viscoelastic. The properties of ultrasound waves traveling through the medium of biological tissues has been extensively studied in recent years and implemented into many important medical tools.

<span class="mw-page-title-main">Sonoporation</span> Technique in molecular biology

Sonoporation, or cellular sonication, is the use of sound in the ultrasonic range for increasing the permeability of the cell plasma membrane. This technique is usually used in molecular biology and non-viral gene therapy in order to allow uptake of large molecules such as DNA into the cell, in a cell disruption process called transfection or transformation. Sonoporation employs the acoustic cavitation of microbubbles to enhance delivery of these large molecules. The exact mechanism of sonoporation-mediated membrane translocation remains unclear, with a few different hypotheses currently being explored.

Treatment for prostate cancer may involve active surveillance, surgery, radiation therapy – including brachytherapy and external-beam radiation therapy, proton therapy, high-intensity focused ultrasound (HIFU), cryosurgery, hormonal therapy, chemotherapy, or some combination. Treatments also extend to survivorship based interventions. These interventions are focused on five domains including: physical symptoms, psychological symptoms, surveillance, health promotion and care coordination. However, a published review has found only high levels of evidence for interventions that target physical and psychological symptom management and health promotion, with no reviews of interventions for either care coordination or surveillance. The favored treatment option depends on the stage of the disease, the Gleason score, and the PSA level. Other important factors include the man's age, his general health, and his feelings about potential treatments and their possible side-effects. Because all treatments can have significant side-effects, such as erectile dysfunction and urinary incontinence, treatment discussions often focus on balancing the goals of therapy with the risks of lifestyle alterations.

Microbubbles are bubbles smaller than one hundredth of a millimetre in diameter, but larger than one micrometre. They have widespread application in industry, medicine, life science, and food technology. The composition of the bubble shell and filling material determine important design features such as buoyancy, crush strength, thermal conductivity, and acoustic properties.

<span class="mw-page-title-main">Sonalleve MR-HIFU</span>

Sonalleve MR-HIFU is a medical system developed by Philips Healthcare for the treatment of uterine fibroids without surgery. The system uses non-invasive high-intensity focused ultrasound (HIFU) guided by magnetic resonance (MR), hence the acronym MR-HIFU. The procedure involves volumetric heating of fibroids with real-time feedback. In June 2017, Philips and Profound Medical announced an agreement to transfer Philips' MR-HIFU business, which includes the Sonalleve system, to Profound Medical.

<span class="mw-page-title-main">Sonodynamic therapy</span>

Sonodynamic therapy (SDT) is a noninvasive treatment, often used for tumor irradiation, that utilizes a sonosensitizer and the deep penetration of ultrasound to treat lesions of varying depths by reducing target cell number and preventing future tumor growth. Many existing cancer treatment strategies cause systemic toxicity or cannot penetrate tissue deep enough to reach the entire tumor; however, emerging ultrasound stimulated therapies could offer an alternative to these treatments with their increased efficiency, greater penetration depth, and reduced side effects. Sonodynamic therapy could be used to treat cancers and other diseases, such as atherosclerosis, and diminish the risk associated with other treatment strategies since it induces cytotoxic effects only when externally stimulated by ultrasound and only at the cancerous region, as opposed to the systemic administration of chemotherapy drugs.

Interventional oncology is a subspecialty field of interventional radiology that deals with the diagnosis and treatment of cancer and cancer-related problems using targeted minimally invasive procedures performed under image guidance. Interventional oncology has developed to a separate pillar of modern oncology and it employs X-ray, ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) to help guide miniaturized instruments to allow targeted and precise treatment of solid tumours located in various organs of the human body, including but not limited to the liver, kidneys, lungs, and bones. Interventional oncology treatments are routinely carried out by interventional radiologists in appropriate settings and facilities.

This is a historical timeline of the development and progress of cancer treatments, which includes time of discovery, progress, and approval of the treatments.

Combinatorial ablation and immunotherapy is an oncological treatment that combines various tumor-ablation techniques with immunotherapy treatment. Combining ablation therapy of tumors with immunotherapy enhances the immunostimulating response and has synergistic effects for curative metastatic cancer treatment. Various ablative techniques are utilized including cryoablation, radiofrequency ablation, laser ablation, photodynamic ablation, stereotactic radiation therapy, alpha-emitting radiation therapy, hyperthermia therapy, HIFU. Thus, combinatorial ablation of tumors and immunotherapy is a way of achieving an autologous, in-vivo tumor lysate vaccine and treating metastatic disease.

Hashim U. Ahmed is a British surgeon, medical researcher and author of publications in the field of prostate cancer diagnostics and treatment; his research has contributed to changes in the way men with suspected prostate cancer and men with prostate enlargement are diagnosed and treated. He is Professor and Chair of Urology at Imperial College Healthcare NHS Trust and Consultant Urological Surgeon at both Charing Cross Hospital and BUPA Cromwell Hospital.

<span class="mw-page-title-main">Katherine Ferrara</span> American engineer

Katherine Whittaker Ferrara is an American engineer who is a professor of radiology at Stanford University. Ferrara has been elected a Fellow of the American Association for the Advancement of Science, Institute of Electrical and Electronics Engineers and American Institute for Medical and Biological Engineering.

<span class="mw-page-title-main">Focused ultrasound for intracranial drug delivery</span> Medical technique

Focused ultrasound for intracrainial drug delivery is a non-invasive technique that uses high-frequency sound waves to disrupt tight junctions in the blood–brain barrier (BBB), allowing for increased passage of therapeutics into the brain. The BBB normally blocks nearly 98% of drugs from accessing the central nervous system, so FUS has the potential to address a major challenge in intracranial drug delivery by providing targeted and reversible BBB disruption. Using FUS to enhance drug delivery to the brain could significantly improve patient outcomes for a variety of diseases including Alzheimer's disease, Parkinson's disease, and brain cancer.

Ultrasound-triggered drug delivery using stimuli-responsive hydrogels refers to the process of using ultrasound energy for inducing drug release from hydrogels that are sensitive to acoustic stimuli. This method of approach is one of many stimuli-responsive drug delivery-based systems that has gained traction in recent years due to its demonstration of localization and specificity of disease treatment. Although recent developments in this field highlight its potential in treating certain diseases such as COVID-19, there remain many major challenges that need to be addressed and overcome before more related biomedical applications are clinically translated into standard of care.

Focused-ultrasound-mediated diagnostics or FUS-mediated diagnostics are an area of clinical diagnostic tools that use ultrasound to detect diseases and cancers. Although ultrasound has been used for imaging in various settings, focused-ultrasound refers to the detection of specific cells and biomarkers under flow combining ultrasound with lasers, microbubbles, and imaging techniques. Current diagnostic techniques for detecting tumors and diseases using biopsies often include invasive procedures and require improved accuracy, especially in cases such as glioblastoma and melanoma. The field of FUS-mediated diagnostics targeting cells and biomarkers is being investigated for overcoming these limitations.

References

  1. 1 2 3 Dubinsky TJ, Cuevas C, Dighe MK, Kolokythas O, Hwang JH (2008). "High-Intensity Focused Ultrasound: Current Potential and Oncologic Applications". American Journal of Roentgenology. 190 (1): 191–199. doi:10.2214/AJR.07.2671. ISSN   0361-803X. PMID   18094311.
  2. ↑ Gelet A, Murat FJ, Poissonier L (2007). "Recurrent Prostate Cancer After Radiotherapy – Salvage Treatment by High-intensity Focused Ultrasound". European Oncological Disease. 1 (1): 60–2. Archived from the original on 4 October 2013. Retrieved 4 October 2013.
  3. ↑ "Food and Drug Administration Approval, ExAblate® 2000 System – P040003". Food and Drug Administration . Retrieved 2 December 2023.
  4. ↑ Robertson VJ, Baker KG (2001). "A review of therapeutic ultrasound: Effectiveness studies" (PDF). Physical Therapy. 81 (7): 1339–50. doi: 10.1093/ptj/81.7.1339 . PMID   11444997.
  5. ↑ Elias WJ, Huss D, Voss T, Loomba J, Khaled M, Zadicario E, Frysinger RC, Sperling SA, Wylie S, Monteith SJ, Druzgal J, Shah BB, Harrison M, Wintermark M (2013). "A Pilot Study of Focused Ultrasound Thalamotomy for Essential Tremor". New England Journal of Medicine. 369 (7): 640–8. doi: 10.1056/NEJMoa1300962 . PMID   23944301.
  6. ↑ Jeanmonod D, Werner B, Morel A, Michels L, Zadicario E, Schiff G, Martin E (2012). "Transcranial magnetic resonance imaging–guided focused ultrasound: noninvasive central lateral thalamotomy for chronic neuropathic pain" (PDF). Neurosurgical Focus. 32 (1): E1. doi:10.3171/2011.10.FOCUS11248. PMID   22208894. S2CID   2231685.
  7. ↑ Magara A, Bühler R, Moser D, Kowalski M, Pourtehrani P, Jeanmonod D (2014). "First experience with MR-guided focused ultrasound in the treatment of Parkinson's disease". Journal of Therapeutic Ultrasound. 2: 11. doi: 10.1186/2050-5736-2-11 . PMC   4266014 . PMID   25512869.
  8. ↑ FDA News Release. "FDA approves first MRI-guided focused ultrasound device to treat essential tremor", FDA , July 11, 2016
  9. ↑ Martin-Fiori, E (2014). "Functional Neurosurgery with MR-Guided HIFU". Intraoperative Imaging and Image-Guided Therapy. New York: Springer. pp. 591–599. doi:10.1007/978-1-4614-7657-3_45. ISBN   978-1-4614-7657-3.
  10. ↑ Chaussy CG, Thüroff S (April 2017). "High-Intensity Focused Ultrasound for the treatment of prostate cancer: A Review". Journal of Endourology. 31 (S1): S30–S37. doi:10.1089/end.2016.0548. PMID   28355119.
  11. ↑ Hu JC, Laviana A, Sedrakyan A (28 June 2016). "High-Intensity Focused Ultrasound for Prostate Cancer". JAMA. 315 (24): 2659–60. doi:10.1001/jama.2016.5002. PMID   27367874.
  12. ↑ Lepor H, Gold S, Wysock J (2018). "Focal Ablation of Prostate Cancer". Reviews in Urology. 20 (4): 145–157. doi:10.3909/riu0809 (inactive 1 November 2024). PMC   6375006 . PMID   30787673.{{cite journal}}: CS1 maint: DOI inactive as of November 2024 (link)
  13. ↑ Ng KK, Poon RT, Chan SC, Chok KS, Cheung TT, Tung H, Chu F, Tso WK, Yu WC, Lo CM, Fan ST (May 2011). "High-intensity focused ultrasound for hepatocellular carcinoma: a single-center experience". Annals of Surgery. 253 (5): 981–987. doi:10.1097/SLA.0b013e3182128a8b. hdl: 10722/135541 . ISSN   1528-1140. PMID   21394012. S2CID   25603451.
  14. ↑ Mauri G, Nicosia L, Xu Z, Di Pietro S, Monfardini L, Bonomo G, Varano GM, Prada F, Della Vigna P, Orsi F (March 2018). "Focused ultrasound: tumour ablation and its potential to enhance immunological therapy to cancer". The British Journal of Radiology. 91 (1083). doi:10.1259/bjr.20170641. ISSN   0007-1285. PMC   5965486 . PMID   29168922.
  15. ↑ Madersbacher S, Schatzl G, Djavan B, Stulnig T, Marberger M (2000). "Long-term outcome of transrectal high- intensity focused ultrasound therapy for benign prostatic hyperplasia". Eur Urol. 37 (6): 687–94. doi:10.1159/000020219. PMID   10828669. S2CID   46793601.
  16. ↑ Sommer G, Pauly KB, Holbrook A, Plata J, Daniel B, Bouley D (2013). "Applicators for magnetic resonance-guided ultrasonic ablation of benign prostatic hyperplasia". Invest Radiol. 48 (6): 387–94. doi:10.1097/RLI.0b013e31827fe91e. PMC   4045500 . PMID   23462673.
  17. ↑ Salgaonkar VA, Diederich CJ (2015). "Catheter-based ultrasound technology for image-guided thermal therapy: current technology and applications". Int J Hyperth. 31 (2): 203–15. doi:10.3109/02656736.2015.1006269. PMC   4659534 . PMID   25799287.
  18. ↑ National Institute for Health and Care Excellence (NICE): Current care pathway (for BPH), August 2018.
  19. ↑ Zhou YF (10 January 2011). "High intensity focused ultrasound in clinical tumor ablation". World Journal of Clinical Oncology. 2 (1): 8–27. doi: 10.5306/wjco.v2.i1.8 . ISSN   2218-4333. PMC   3095464 . PMID   21603311.
  20. ↑ Sapareto SA, Dewey WC (1984). "Thermal dose determination in cancer therapy". International Journal of Radiation Oncology, Biology, Physics. 10 (6): 787–800. doi:10.1016/0360-3016(84)90379-1. PMID   6547421.
  21. ↑ Mouratidis PX, Rivens I, Civale J, Symonds-Tayler R, Haar Gt (1 January 2019). "'Relationship between thermal dose and cell death for "rapid" ablative and "slow" hyperthermic heating'". International Journal of Hyperthermia. 36 (1): 228–242. doi: 10.1080/02656736.2018.1558289 . ISSN   0265-6736. PMID   30700171.
  22. ↑ Huisman M, Lam MK, Bartels LW, Nijenhuis RJ, Moonen CT, Knuttel FM, Verkooijen HM, van Vulpen M, van den Bosch MA (2014). "Feasibility of volumetric MRI-guided high intensity focused ultrasound (MR-HIFU) for painful bone metastases". Journal of Therapeutic Ultrasound. 2: 16. doi: 10.1186/2050-5736-2-16 . PMC   4193684 . PMID   25309743.
  23. ↑ Köhler MO, Mougenot C, Quesson B, Enholm J, Le Bail B, Laurent C, Moonen CT, Ehnholm GJ (2009). "Volumetric HIFU ablation under 3D guidance of rapid MRI thermometry". Medical Physics. 36 (8): 3521–35. Bibcode:2009MedPh..36.3521K. doi:10.1118/1.3152112. PMID   19746786.
  24. ↑ Monteith SJ, Kassell NF, Goren O, Harnof S (2013). "Transcranial MR-guided focused ultrasound sonothrombolysis in the treatment of intracerebral hemorrhage". Neurosurgical Focus. 34 (5): E14. doi: 10.3171/2013.2.FOCUS1313 . PMID   23634918.
  25. ↑ Haen SP, Pereira PL, Salih HR, Rammensee HG, Gouttefangeas C (2011). "More Than Just Tumor Destruction: Immunomodulation by Thermal Ablation of Cancer". Clinical and Developmental Immunology. 2011: 1–19. doi: 10.1155/2011/160250 . PMC   3254009 . PMID   22242035.
  26. ↑ Wu F (2013). "High intensity focused ultrasound ablation and antitumor immune response". The Journal of the Acoustical Society of America. 134 (2): 1695–701. Bibcode:2013ASAJ..134.1695W. doi:10.1121/1.4812893. PMID   23927210.
  27. ↑ Leighton T (1997). Ultrasound in food processing. Chapter 9: The principles of cavitation: Thomson Science, London, Blackie Academic and Professional. pp. 151–182.{{cite book}}: CS1 maint: location (link)
  28. ↑ Levario-Diaz V, Bhaskar P, Galan MC, Barnes AC (22 May 2020). "Effect of acoustic standing waves on cellular viability and metabolic activity". Scientific Reports. 10 (1): 8493. Bibcode:2020NatSR..10.8493L. doi: 10.1038/s41598-020-65241-4 . ISSN   2045-2322. PMC   7244593 . PMID   32444830.
  29. ↑ Hariharan P, Myers MR, Banerjee RK (21 July 2007). "HIFU procedures at moderate intensities—effect of large blood vessels". Physics in Medicine and Biology. 52 (12): 3493–3513. Bibcode:2007PMB....52.3493H. doi:10.1088/0031-9155/52/12/011. PMID   17664556. S2CID   26124121.
  30. 1 2 3 Izadifar Z, Izadifar Z, Chapman D, Babyn P (7 February 2020). "An Introduction to High Intensity Focused Ultrasound: Systematic Review on Principles, Devices, and Clinical Applications". Journal of Clinical Medicine. 9 (2): 460. doi: 10.3390/jcm9020460 . ISSN   2077-0383. PMC   7073974 . PMID   32046072.
  31. ↑ Kotopoulis S, Wang H, Cochran S, Postema M (2011). "Lithium niobate transducers for MRI-guided ultrasonic microsurgery" (PDF). IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. 58 (8): 1570–1576. doi:10.1109/TUFFC.2011.1984. PMID   21859576. S2CID   11382728.
  32. ↑ Medel R, Monteith SJ, Elias WJ, Eames M, Snell J, Sheehan JP, Wintermark M, Jolesz FA, Kassell NF (2012). "Magnetic Resonance–Guided Focused Ultrasound Surgery". Neurosurgery. 71 (4): 755–763. doi:10.1227/NEU.0b013e3182672ac9. ISSN   0148-396X. PMC   4104674 . PMID   22791029.
  33. ↑ Belzberg M, Mahapatra S, Perdomo-Pantoja A, Chavez F, Morrison K, Xiong KT, Gamo NJ, Restaino SA, Thakor N, Yazdi Y, Iyer R, Tyler B, Theodore N, Luciano MG, Brem H, Groves M, Cohen AR, Manbachi A (2020). "Minimally invasive therapeutic ultrasound: Ultrasound-guided ultrasound ablation in neuro-oncology". Ultrasonics. 108 (12): 106210. doi: 10.1016/j.ultras.2020.106210 . PMC   8895244 . PMID   32619834.
  34. ↑ Cafarelli A, Mura M, Diodato A, Schiappacasse A, Santoro M, Ciuti G, Menciassi A (25–29 August 2015). "A computer-assisted robotic platform for Focused Ultrasound Surgery: Assessment of high intensity focused ultrasound delivery". 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). pp. 1311–1314. doi:10.1109/EMBC.2015.7318609. ISBN   978-1-4244-9271-8. PMID   26736509. S2CID   4194253.
  35. 1 2 Chen PH, Hsieh KS, Huang CC (2017). "An Acoustic Tracking Approach for Medical Ultrasound Image Simulator". Journal of Medical and Biological Engineering. 37 (6): 944–952. doi:10.1007/s40846-017-0258-9. ISSN   1609-0985. PMC   6208925 . PMID   30416414.
  36. ↑ Ebbini ES, Ter Haar G (2015). "Ultrasound-guided therapeutic focused ultrasound: Current status and future directions". International Journal of Hyperthermia. 31 (2): 77–89. doi: 10.3109/02656736.2014.995238 . ISSN   0265-6736. PMID   25614047. S2CID   23590340.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.