MR Guided Focused Ultrasound (MRgFUS) Overview of Present and Future Clinical Research Studies
1. MR Guided Focused Ultrasound (MRgFUS) Overview of Present and Future Clinical Research Studies David Gianfelice MD University health Network Toronto, Canada Research Support Insightec Ltd.
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3. How does Focused Ultrasound work? Focused ultrasound generates heat, ablating tissue only at the focal point. Spot sizes Length: 10-45 mm Diameter: 2-10 mm Treatment illustration Perpendicular to beam Parallel to beam
4. Why is MR guidance and control important? 3D Imaging for precise tumor targeting Beam path visualization for controlled treatment MR thermometry for real-time temperature feedback Post treatment contrast imaging for precise treatment validation CLOSED LOOP THERAPY
5. Clinical applications and research* * All research studies under IDE - investigational use only Bone Tumors Liver Tumors Breast Cancer Uterine Fibroids Brain treatments Prostate
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10. Courtesy of Mt. Sinai Hospital, Toronto Clinical results – pain palliation of bone metastases case Clinical results: Patient VAS pain score dropped from 7 (severe) to 0 (no pain) Duration of treatment: 50 min Only 11 sonications required IDE Caution-Investigational Device Limited by United States Law to Investigational Use.
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19. ExAblate for prostate – initial animal results Treatment effects in canine prostate The results show a good correlation between expected dose and NPV and similarity to the TTC stained tissue: WS expected dose: Non-perfused volume, T1w+contrast imaging: TTC stained tissue:
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21. Uterine fibroids cases Courtesy of Sheba Medical Center, Tel Aviv, Israel T1w contrast enhanced image before treatment T1w contrast enhanced image immediately post-treatment T2w planning image with dose overlay Outcome: Marked reduction in all symptoms. Fibroid reduced to 455 cc after one month and 298 cc after 36 months. 40 years old, 526cc fibroid Symptoms: heavy bleeding, cramps and dyspareunia. 49 year old, multiple fibroids Symptoms: pressure & frequent urination Outcome: Fibroids totally ablated, marked reduction in symptoms T2w image before treatment T1w contrast enhanced image one month after treatment T1w contrast enhanced image 36 months after treatment
25. Brain tumors - closed skull safety study Axial temperature map of thermal spot Helmet shaped transducer Patient set up Patient entering MR
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28. Total sites: 60 28 – Americas 17 – Europe 15 – Asia Clinical partners Place cursor on orange square to view site names Americas Europe Asia 28 sites 17 sites 15 sites
29. Click to return to site map 31 sites Americas Research sites highlighted
30. Click to return to site map Europe 17 sites Research sites highlighted
31. Click to return to site map Asia 15 sites Research sites highlighted
The focused ultrasound beam is generated by a phased array transducer which is located in the patient table and passes through a water bath and gel pad which create acoustic coupling with the patient. The effect of focusing ultrasound energy is similar to that of using a magnifying glass to focus the sun’s energy on a single point. However, unlike light, ultrasound energy can easily pass through the skin and propagate through tissue to converge to a focal point inside the body. The focal point has the shape of a small bean. In few seconds, the tissue at the focus reaches a temperature level that causes cell destruction. The system then moves to another spot to ablate it,until all the planned spots are treated. The size of the sonications can be varied, depending on the size and depth of the focal volume to be treated, ranging from 1x2mm to 10x30 mm.
Focused Ultrasound has been identified as the “ideal surgical tool” for over 40 years, however, without the ability to visualize or control the treatment, it was not accepted. The advent of Magnetic Resonance provided just such a tool: precise visualization of the tumor, other organs, and the beam path for exact targeting and to ensure that there are no unwanted structures or organs in the beam path; real time thermal imaging to evaluate if the beam actually reached the target and if so, if it reached coagulation temperatures. If it doesn’t reach the right temperature, then the physician has the ability to change the parameters. This closed loop therapy paradigm provides the ability to get immediate feedback, react to that feedback, and know immediately what the outcome is. All this provides the physician with much more information than traditional surgical procedures. This ensures efficacy and safety of the procedure.
Wide range of applications under development by InSightec. We have embarked on a very extensive clinical research program.
Also in the Inclusion: Bone metastasis are device accessible Also in the exclusion: Impending fracture or, at some sites, weight bearing bone Targeted tumor less then 10mm from skin, (avoid the risk of skin burn) Targeted tumor less then 10mm from major nerves, (avoid the risk of neural damage) Note: it is ok to have Mets in the spinal column as long as they are not the targeted ones
The illustration shows the usage of wide beam approach on a pelvic tumor. Difficult to see here but patient is not on back but somewhat tilted Details in the next slides
Breast cancer is the leading form of cancer among women, and ranks second among cancer deaths in women, behind lung cancer. 200,000 women are diagnosed with breast cancer annually and nearly 40,000 women die annually of breast cancer. The gold standard treatment is surgical removal of the tumor and a surrounding area of normal tissue, or lumpectomy, typically in combination with additional therapies such as radiation therapy or chemotherapy to prevent recurrence. InSightec has conducted several Phase I and Phase II studies with 120 patients. Early studies showed the importance of tumor margin delineation in order to totally treat tumors. We recently completed a Phase II study in Japan with contrast enhancement used in planning images, which enabled the physicians to clearly identify the borders of the lesions and identify small lesions that are often overlooked. These lesions were then excised with results of 97% necrosis. This pathology, which comes up after you click ones shows the slice by slice pathology of a biopsied tumor. You can see the ablated cancer, the boundary of the necrosis, to ensure that an appropriate margin is taken and the treatment boundary.
A press release on this topic has been issued prior to RSNA. This Phase II trial is intended to demonstrate that ExAblate 2000 can effectively and non-invasively serve at the method for destruction of the localized tumor versus conventional lumpectomy. The results of this study will provide the basis for a large scale excisionless pivotal study. For this study, MRgFUS will be used to treat the tumor plus a margin of normal tissue. A contrast MR will be performed 14-21 days later to assess the completeness of the treatment. Following this, a conventional lumpectomy will be performed and the cancerous growth will be excised for pathological evaluation, and the patient will receive the conventional standard of care therapy (radiation and/or chemotherapy). This study will use the pathology data to determine if ExAblate can destroy 95% of the tumor or more of the tumor volume. A secondary endpoint will be to evaluate the ability of contrast MR to identify those patients with residual tumor post MRgFUS treatment. The study will be involve 200 patients at up to 10 sites worldwide.
A trial is currently on-going in Japan to treat breast cancer without surgical removal of the treated lesion. Patients will be followed up for 5 years So far five women have been treated.
Uterine Fibroids are a very prevalent condition and occur in up to 80%, with 25% of women requiring some form of treatment to alleviate symptoms. UF are the leading cause of hysterectomy, with up to 1/3 of all hysterectomies performed for UF. Hyst. and Myomectomy, the leading treatment alternatives are both surgical treatments which require hospitalization and extensive recovery time. UAE, generally requires an overnight stay in the hospital and if often accompanied by significant pain and post-embolization syndrome. Drug therapy is a temporary measure, which is often a prelude to hysterectomy or myomectomy. Over 2200 women have been treated with ExAblate with close to 92% experiencing symptom relief.improvem
Upper case: 3 year follow-up without return of symptoms. The main shrinkage occurs in the months following the treatment. Lower case: Multiple fibroids can be treated using the ExAblate system. This example shows a patient with 2 fibroids treated successfully.
Our “closed-skull” protocol will treat up to 10 patients with brain tumors. The protocol does not require the participants to undergo a prior craniectomy procedure. To date, three patients have been treated at BWH with a protocol to demonstrate safety- meaning no skull heating, which might cause damage to the brain surface. The results were reported to the FDA and based on these results the FDA approved a continuation of the study with emphasis on efficacy.