MRI GUIDED FOCUS ULTRASOUND:

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MRI GUIDED FOCUS ULTRASOUND New approach for
Bone Metastases Treatment
Prof. Raphael Catane Oncology Division Sheba
Medical Center November 2006
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Bone Metastases - General
Pain is the most common symptom found in 70 of
patients with bone metastases
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Bone Metastases - General

• Characteristic of pain
• -Severe, often requiring heavy narcotic use
• -Fairly constant, even at night.
• -Worsen in different positions, such as standing
  up, which may compress the cancer in a weight
  bearing bone.

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Bone Metastases - Radiology
X-Ray
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Bone Metastases - Radiology
Bone scan (Tc-99)
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Bone Metastases - Radiology
CT
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Treatment

• Radio-therapy
• 90 some relief, 50 complete relief
• Single fraction 800-1000cGy or 400cGy 5 or
  300cGy 10
• Temporary effect
• May affect surrounding tissues
• Can not be repeated
• Radioactive Strontium
• Occasionally effective
• Bisphosphonates
• Routinely administered prevent fractures and
  hypercalcemia
• Moderate analgesic effect

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Treatment

• Surgery
• Suitable for selected patients and cases
• RF ablation
• In research stages invasive

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MRI guided Focused U/S

• Breakthrough technology which combines
• High intensity focused ultrasound beam that heats
  and destroys targeted tissue, non-invasively
• Magnetic resonance imaging system (MRI) which
  visualizes patient anatomy, and controls the
  treatment by monitoring the tissue effect in real
  time

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Sound Wave - what is it?
Sound is a mechanical disturbance caused by a
vibration. Sound waves propagate through matter
by cyclic compression and decompression of the
particles that make up the matter, resulting in
regions of high and low pressure, US is a
mechanical wave.
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Wave Properties

• Wave length (? ) The distance between
  identical points on the wave
• Period ( T ) The time for a point on the
  wave to undergo one complete oscillation.
• Frequency ( f ) f 1/T cycles/second
• 1 Hz 1 cycle/sec
• Amplitude ( A ) The maximum displacement of
  a point on the wave.

Time
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• In soft tissue
• Narrow, point-shaped focus is required
• High energy density at focal point

• In bone tissue
• Wide Beam Approach
• Low energy usage
• Shorter Treatment Time

Ablated Tissue
Bone
Acoustic Beam
Transducer
Transducer
Typical Sonication Energy 1000J
Typical Sonication Energy 2500J
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Thermal ablation

• Thermal Ablation Dose is Related to Exposure time

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MRgFUS for Bone Metastases
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Treatment of Bone Metastases with MRgFUS

• FUS theoretical advantages compared to radiation
• Less structural damage to bone
• Immediate effect
• Bone re-growth
• Can repeat treatment as many times as needed

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Pig experiment
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MR Thermal Image
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Animal Trials
Macro Pathology image12 weeks post treatment
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Animal Trials
Adjacent to Lesion
Bone re-growth 7 weeks after Tx
Center of Lesion
Micro Pathology images10 days post treatment
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Patient Selection
Who is eligible for the study

• Patients with histologically or
  cytologically confirmed malignant disease with a
  bone lesion
• Persistent pain from at least one site of bone
  metastases at the present we treat only pelvic
  mets
• VAS pain score 4, when VAS test taken without
  medication,
• Had been treated with radiotherapy and is
  resistant or had relapsed.

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VAS (Visual Analog Scale)
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MRgFUS for Palliation of Bone Metastasis

• 3 study centers
• Sheba (Ramat Gan, Israel),
• Charite (Berlin, Germany)
• UHN (Toronto, Canada)
• 36 treatments performed targeting 32 lesions in
  30 patients worldwide
• 10 patients were recruited in Sheba (Israel), 12
  treatment done

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Sheba experience

• Patient characteristic
• Age 41-70
• PS 1-3
• Tumor Breast,Colon,Lung,Prostate,Rectum
• Site of metastases Pelvis

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Sheba experience

• No significant device related adverse event
• Only one patient failed to tolerate treatment (
  pain)
• Most of the patients report reduction of pain and
  / or medication dosage
• Follow-up of up to 6 months

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Sheba experience

• Evaluation
• Patients pain level VAS score from 0 to 10
• Patients medications
• Changes in frequency and dosage of analgesic
  consumption
• Post treatment and follow up images
• Volume of tissue that shows evidence of treatment
  effect on contrast enhanced MR images

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Case 1

• 44 year old female patient
• Primary Tumor Breast Cancer
• Targeted lesion in the left iliac bone adjacent
  to the ilio-sacral joint
• MRgFUS procedure performed under mild sedation
• 34 sonications
• One hour procedure duration

Axial T2w MR image
CT image
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Case 2

• 70 year-old male patient
• Primary Tumor Prostate Cancer
• Bone metastases in the left iliac bone
• MRgFUS procedure performed
• 26 sonications
• 48 minutes procedure duration

CT image
Axial T2w MR image
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Conclusions

• MRgFUS
• Produces a Controlled Well-Localized Damage to
  impaired bone and soft tissue in close proximity
  to bone.
• Provides Durable Palliative Benefit

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THANK YOU