The Yesterday, Today and Tomorrow of Focused Ultrasound Surgery 1
Terms and Principle Evolution of surgery in the last 200 years Open Surgery Laparoscopic Surgery Focused Ultrasound Surgery 2
Terms and Principle Evolution of surgery in the last 200 years Open Surgery Laparoscopic Surgery Focused Ultrasound Invasive Noninvasive Focused ultrasound treatments can be performed on an outpatient basis, require no incisions, and can result in minimal discomfort and few complications, allowing for rapid recovery. Surgery 3
Terms and Principle HIFU : High Intensity Focused Ultrasound HITU : High Intensity Therapeutic Ultrasound FUS : Focused Ultrasound Surgery The fundamental principle is analogous to using a magnifying glass to focus beams of sunlight on a single point to burn a hole in a piece of wood. With focused ultrasound, an acoustic lens is used to concentrate multiple intersecting beams of ultrasound on a target deep in the body with extreme precision. 4
Terms and Principle Where each individual beam passes through the tissue, there is no effect. But, at the focal point, the convergence of the multiple beams of focused ultrasound energy results in many biological effects, creating the possibility of treating a variety of disorders. 5
Terms and Principle 6
Terms and Principle Focused ultrasound surgery is an early stage, non-invasive therapeutic technology with the potential to transform the treatment of many medical disorders by using ultrasonic energy to target tissue deep in the body without incisions or ionizing radiation. 7
Terms and Principle HIGH INTENSITY THERAPEUTIC ULTRASOUND (HITU) EQUIPMENT Equipment for the generation and application of ultrasound to a patient for therapeutic purposes with the intention to destroy, disrupt or denature living tissues or non-tissue elements (for example liquids, bubbles, micro-capsules) and which aims notably at making treatments through actions of ultrasound having mechanical, thermal or more generally physical, chemical or biochemical effects. 60601-2-62 IEC:2013 8
Terms and Principle Focused ultrasound surgery is the union of two innovative technologies: focused ultrasound which provides the energy to treat tissue deep in the body precisely and noninvasively magnetic resonance or ultrasound imaging which is used to identify and target the tissue to be treated, guide and control the treatment in real time, and confirm the effectiveness of the treatment 9
Ultrasound Imaging Guided Terms and Principle As a result of acoustic property change of the tissues necrosed coagulatively, grey scales of ultrasound images in the same area around the focus are different before and after treatment, which could be used for real-time monitoring and effect assessment during treatment in ultrasound guided HIFU therapeutic system. 10
Real-time Monitoring with US Imaging Before Treatment After Treatment 11
Ultrasound Guided HIFU System Chongqing Haifu - JC 12
MR Imaging Guided Terms and Principle High image resolution and non-invasive temperature measuring in deep tissues provide a technically reliable approach of real-time monitoring and effect assessment during treatment for MRI guided HIFU therapeutic system. 13
MRI Guided HIFU System InSightec TxSonics - Exablate 14
Yesterday Lynn 1942 Idea of neurosurgery Bill Fry Their highest priorities were to establish a Frank Fry 1946 laboratory that would develop ultrasonic surgical procedures for the mammalian brain and to study the detailed neuroanatomy of the mammalian central nervous system. 15
Yesterday They developed a complicated HIFU system. Using X-ray for Guidance Carrying out Animal Trials 16
Yesterday A steam tunnel below the University of Illinois electrical engineering building served as the first office and lab space for Bill Fry (seated) and his brother, Frank Fry (leaning over). 17
Amplifier Transducer Water Basin Impedance Matching Controller Test Table Motion System Heat Transform Controller 18
Yesterday Meanwhile, Russell Meyers, a professor of neurosurgery at the medical school of the University of Iowa, developed an interest in human ultrasonic neurosurgery and in 1957 successfully conducted what we understand to be the first ultrasonic surgery on a human brain. In the period 1958 62, some 88 patients underwent ultrasonic neurosurgery to treat various afflictions, including Parkinson s disease, cerebral palsy, the aftereffects of stroke, and phantom images and pain following amputation. 19
Yesterday Pioneering ultrasonic neurosurgery was conducted by Russell Meyers (second from left). Here, Meyers is accompanied by Frank Fry (left) and Bill Fry (right), who were instrumental in developing the techniques that enabled the operation. 20
Yesterday In 1980s, with development of the imaging and computer technology, HIFU became the focus again. USA, UK, China, France, Japan, Israel, Germany, Canada. Prostate, Bladder, Kidney, Liver, Uterus, Soft Tissue, Breast, Bone, Eye. 21
Yesterday In February, 2004,American Association for the Advancement of Science (AAAS) took HIFU technology as one of the most advanced technologies in the world 22
Today Even though focused ultrasound is currently in the early stages of development and adoption, it has the potential to transform the treatment of a variety of serious medical conditions, including neurological disorders, many cancers, cardiovascular disease and endocrine disorders. All indicators point toward the evolution of this platform technology into a robust medical field, with the pace of research and development, publications, patient treatments and the number of device manufacturers all increasing rapidly in the past few years. Report from Focused Ultrasound Foundation,2016 23
Example Today Evaluation of HIFU Ablation for Uterine Fibroids: an IDEAL Prospective Exploration Study The study benefited from the collaboration with Surgical Trial Unit at Oxford University for trial design. It was designed as a prospective multi-centre patient choice cohort study (IDEAL Exploratory study). It deployed 20 medical centers in China and enrolled 2411 Chinese women with symptomatic fibroids. The Chinese Cochrane Centre provided services in the trial registry, design, data collection, quality control, data analysis and evaluation. When East Meets West Han Qide 24
Example Today Evaluation of HIFU Ablation for Uterine Fibroids: an IDEAL Prospective Exploration Study It has produced, up to date, the most convincing clinical research evidence establishing the efficacy, safety and social economic benefits of HIFU for the management of uterine fibroids. The findings of this study support the need for a randomized controlled trial (RCT) in order to definitively establish HIFU as a standard of care for fibroids. When East Meets West Han Qide 25
Example Today 26
Example Today This large IDEAL Prospective Exploration Study paves the way for a future gold standard RCT comparing HIFU with the conventional therapies such as myomectomy and hysterectomy for patients suffering with fibroids, to ascertain efficacy data. Furthermore, the rapid postprocedure recovery reported with HIFU has obvious financial and patient satisfaction implications that can also be confirmed in a RCT. N Tempest, D Hapangama Liverpool Women s Hospital, University of Liverpool, Liverpool, UK 27
Example Today Therefore, we support this novel approach for the treatment of fibroids and the proposed RCT, an excellent practical outcome for this IDEAL study in assisting in the development of definite RCTs for complex interventions. HIFU will potentially add a novel dimension to the limited treatment options currently available for many women with symptomatic fibroids worldwide. N Tempest, D Hapangama Liverpool Women s Hospital, University of Liverpool, Liverpool, UK 28
Example Today A great demonstration of this comes from a study in 20 Chinese hospitals comparing three treatments for uterine fibroids: myomectomy, hysterectomy, and high intensity focused ultrasound (HIFU). HIFU comes out clear favourite for effectiveness and rapid recovery, to such a degree that it could be argued that a randomised trial is no longer needed. BMJ( BJOG doi: 10.1111/1471-0528.14689) 29
Today 66 92 158 Report from Focused Ultrasound Foundation,2018 30
Today Report from Focused Ultrasound Foundation,2018 31
Today Report from Focused Ultrasound Foundation,2018 32
Today Focused ultrasound is a platform technology that affects tissue through multiple mechanisms, thereby enabling the treatment of a wide variety of medical disorders. Report from Focused Ultrasound Foundation,2018 33
Tomorrow Focused ultrasound offers a disruptive, gamechanging alternative or complement to surgery, radiation therapy, drug delivery, and cancer immunotherapy. This revolutionary technology has the potential to increase the quality and length of life and decrease the cost of care for a lot of medical disorders. 34
Tomorrow The future is bright, the road is tortuous. 35
Metrological Problems Tomorrow In HIFU/HITU/FUS, we face a lot of metrological problems which could be very difficult to deal with, or even could not be solved, by using the existed standard methodology. Very high pressures Very high intensities Strong focusing Nonlinear harmonics Acoustic saturation and nonlinear loss 36
Metrological Problems Tomorrow The ability to generate such high temperatures within tissue brings with it the absolute requirement to ensure that the treatment is delivered to the correct level and at the correct site. This in turn means that accurate methods of predicting the dose and monitoring performance are required. Consequently, reliable measurement and characterisation methods are needed for this application above all others. IEC/TR 62649 37
Metrological Problems Tomorrow Medical ultrasound fields in the MHz frequency range are typically characterised in water by measuring the spatial and temporal distribution of pressure using a piezoelectric hydrophone, and by measuring the radiation force on a target which intercepts the entire field. IEC/TR 62649 38
Metrological Problems Tomorrow In normal practice, no attempt is made to measure intensity (or the distribution of intensity) directly but it is derived from the measurement of pressure by assuming that the local pressure and particle velocity are in phase and therefore that the intensity is proportional to pressure squared (a plane-wave assumption). IEC/TR 62649 39
Metrological Problems Tomorrow Ultrasound power is not directly measured either but is derived either by integrating the derived intensity over a plane which intersects the field, or by measuring the radiation force experienced by a target and assuming that power is proportional to the radiation force and that the constant of proportionality can be determined from the acoustic and geometric properties of the target (another plane-wave assumption). IEC/TR 62649 40
Metrological Problems Tomorrow It can be difficult or inaccurate to apply many of the standard measurement methods to HITU fields, either due to fundamental measurement issues or to practical problems. IEC/TR 62649 41
Metrological Problems Tomorrow For radiation force balances, the major problems relate to: shielding by bubbles; thermal damage of target; force dependence on field geometry, not just on power; measurements away from the focal plane; extreme nonlinear effects including shock loss. IEC/TR 62649 42
Metrological Problems Tomorrow For hydrophone measurements, the major problems relate to: shielding by bubbles; thermal or cavitation damage; non-ideal frequency response; non-ideal directional response/spatial-averaging; high pressure levels; high harmonic content; off-axis measurements. IEC/TR 62649 43
Metrological Problems Tomorrow Patients and doctors assume that ultrasound treatments are based on a good understanding of the required dose in tissue (in the same way as radiotherapy or phototherapy for instance) but in fact no such metrological infrastructure exists. Standardised and traceable dose quantities have not yet been developed for medical ultrasound applications. JRP HLT03 (DUTy) 44
Metrological Problems Tomorrow This lack of a traceable dosimetry framework makes it impossible to determine dose-response curves and to arrive at robust, personalised treatment plans. Consequently, over- or under-treatment and harm to the patient may occur, or valuable new treatments may not be taken up because they are too inconsistent. JRP HLT03 (DUTy) 45
Tomorrow Project s Scientific and technical objectives 1. Development of a dose concept for therapeutic ultrasound; 2. Development of phantoms and measurement techniques for testing of dose concepts including the characterisation of measurement methods and treatment planning software; 3. Development of test methods for the assessment of commercial machines and comparison of treatment effects and efficiency; 4. Modelling and validation of linear and non-linear ultrasound propagation through phantoms and anatomical structures; 5. Development of methods to improve the accuracy of the individual treatment including use of anatomical data. JRP HLT03 (DUTy) 46
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