MRgFUS for uterine fibroids- The new generation

Y. Inbar, MD

1st Europian MRI SymposiumSept. 2011

Sheba Medical Center, Israel

Development goals

Increased treatment efficacy Enhance treatment safety Wider patient selection

An Enhanced System for MRgFUS Treatment of Uterine Fibroids

11.5 cm7.3 cm

6.1 cm8.6 cm

Highest position Lowest position

30 cm2

60 cm2

50 cm2100 cm2

Former systemCurrent system

• Higher energy density at the focus

• Lower energy density on near & far field.

Transducer ElevationThe 5th Degree of Freedom

Transducer automatically moves up or down for an optimal treatment

shaping the beam by closing elements in the transducer, enables to overcome anatomic obstacles without the need to steer the whole beam around it. It may allow wider patient selection and greater treatment volume

Beam shaping – Anatomic Aperture

Coronal View

Sagittal View

Beam shaping – Anatomic Aperture

Spots length varies from 10mm to 70mm Optimal volumetric packing to maximize treatment volume Longer sonications for reduced treatment time

Steering along the beam Higher dose volumes by taking advantage of the residual heating of

the sonication Spot size control

Elongated

Nominal Short

Elongated

Nominal Short

Spot Formation and Length

Automatically arranges spots to cover maximum targeted volume at a minimal treatment time, while optimizing:

Automatic 3D Treatment Planner

Former Planner New Planner

Spot types LEDRs Shapes Transducer aperture Transducer height Interleave mode Automatic tilt

Movement Detection

After movement(Current image)

Before movement(Reference image)

An automatic feature for detecting patient or organ’s movement.

Dose Transfer In case of patient movement

If the patient moved and there is a need to acquire new planning images, the physician can copy the accumulated thermal dose to the new MR images based on the re-drawn ROT.

The system automatically computes treatment plan only on regions not treated yet.

Before movement After movement

Manual adjustment

Participating Sites

Israel- Sheba Medical Center Jaron Rabinovici Yael Inbar Dahlia Admon Ariela Siton

Russia- COGP Yulia Kurashvili Alexander Stepanov

France- Tours Frédéric Patat Aurore Bleuzen Morgane Fournier

Objective

To evaluate safety and ablation efficacy of the ExAblate 2100 UF V2 system when treating symptomatic uterine fibroids

Study Design

Prospective, nonrandomized, multi-center study 40 patients (Israel, Russia, France, England)

Women with symptomatic uterine fibroids- UFS-QOL > 21

MRI confirmed fibroids that are accessible 1 month f/u- clinical

Results

Data includes 34pts. (41 tx.)- Israel, Russia, France- Total treated 37 pts.- 44 treatments.- 3 pts. Excluded- technical difficulties

Patient’s Age 29-54y (Av. 44y) BMI 19-37 (Av. 25)

Results

Treated fibroid volumes 20-626cc (Av. 226cc) No. of fibroid treated 1-5 (Av. 2) Fibroid Intensity on T2w images:

- 62.5% (30/48) fibroids- hypointense

- 37.5% (18/48) fibroids- hyperintense

isointense heterogenous

Adverse Events

No SAE Minor AE included abdominal pain,

nausea, diarrhea, back pain, fatigue, slight fever

catheter related urinary symptoms (4)

bleeding (1)

small area of subcutaneous heating from treatment (1)

UF-2 (UF032 Sheba patients)

UF-1 (78 Sheba research patients)

No. of sonications 941 2546

Average Energy 4129J 2546J

Max. Energy 7779J 4800J

Average Energy

Non Perfused Volume (NPV) ratio

Average NPV ratio- 67.8 (+/-18.5%)

Hypointense (30)71.3%

Hyper/isointense (18)61.8%

Non Perfused Volume (NPV) ratio

Stewart et al. Obstet Gynecol 2007-----Av. NPV ratio 21.9% (N=359)Okada et al. Ultrasound in Obstet Gynecol 2009-----Av. NPV ratio 46.6% (N=287)Leblang et al. AJR 2010-----Av. NPV ratio 55% (N=80)

Matzko & Trumm, 2nd MRgFUS Symposium 2010-----Av. NPV ratio 59.1% (N=41)

%

UF2

Patient age: 45 years old

Fibroids volume: 140cc

Treatment time: 180 minutes

Symptoms: Heavy menstrual bleeding, blood clots and pain .

Fibroids Intensity: Iso-Intense with bright portion on T2w Images

Results: 75% NPV with no adverse effects

Sagittal T2wSagittal T1w+c Pre-Treatment

5 axis motion increased energy density in focus- allowed treating Hyper Intense areas.

Sagittal T1w+c Post treatment

UF032-6001

Patient age: 48 years old

Fibroids volume: 240cc

Fibroids Intensity: Iso-Intense on T2w Images

Symptoms: Heavy menstrual bleeding and bulgy belly.

Sonication time: 180min

Results: 91% NPV with no adverse effects

Sagittal T2wSagittal T1w+c Pre-Treatment

Beam shaping allowed treating closer to sensitive organs and reaching the fibroid’s superior portion.

Sagittal T1w+cPost treatment

UF032-6005

Patient age: 45 years old

Fibroids volume: 120cc

Fibroids Intensity: Hypointense on T2w Images

Symptoms: Frequent urination. 2 y post myomectomy with large scar

Sonication time: 193 min

Results: 83% NPV with no adverse effects

• No-pass zone LEDR- to avoid sonicating through a transverse large scar- tilting and aperture

• Sonications through the scar- with transducer up and without tilt- low energy density on the skin

UF032-6020

Sagittal T2w pre tx Sagittal T2w post tx Sagittal T1w+c post txSagittal T1w+c pre tx

Adenomyosis

Patient age: 39 years old

Adenomyosis and tiny fibroid

Symptoms- menometrorrhagia

To avoid bowels we used a

salad bowl

Sonication time: 160min

Results: focalAD NPV 79%

tiny fibroid NPV 100%.

Conclusions

The new enhanced MRgFUS system seems to allow:- A wider patient selection (bowel loops, scars, fibroid

intensity, etc)- Increase sonication volumes

- Enable better treatments of hyperintense fibroids

- Maintain the known safety profile of MRgFUS

Thank You

Israel- Sheba Medical Center Jaron Rabinovici Yael Inbar Dahlia Admon Ariela Siton

InSightec Mor Dayan Amit Sokolov

Russia- COGP Yulia Kurashvili Alexander Stepanov

France- Tours Frédéric Patat Aurore Bleuzen Morgane Fournier