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Overview of Overview of Gamma KnifeGamma Knife®® Surgery Surgery

Dr. Sandra Vermeulen, M.D.Dr. Sandra Vermeulen, M.D.Swedish Cancer InstituteSwedish Cancer Institute

Northwest Hospital Gamma Knife CenterNorthwest Hospital Gamma Knife CenterSeattle, WashingtonSeattle, Washington

Learn more at:Learn more at:www.DoctorVermeulen.comwww.DoctorVermeulen.com

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Years of Clinical ExperienceYears of Clinical Experience

1968The first prototype of Leksell Gamma Knife® was installed in Stockholm, Sweden. 1999

Elekta introduces the Leksell Gamma Knife® C.

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Leksell Gamma KnifeLeksell Gamma Knife®® C C

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Gamma Knife® SurgeryGamma Knife® Surgery

The delivery of a single, high dose of irradiation to a small and critically located intracranial volume through the intact skull.

201 beams intersecting in one focal point

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Leksell Gamma KnifeLeksell Gamma Knife®® C C

Helmet Supports

Automatic Positioning System

Treatment Couch with Mattress

Protection Panels

Shielding Doors

Shielding

Cobalt-60 sources

Plastic Cover

Beam Channel

Helmet with Collimators

Helmet in Treatment Position

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The Treatment ProcedureThe Treatment Procedure

1. Frame Fixation

2. Diagnostic Imaging

3. Treatment Planning

4. Treatment

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1. Frame Fixation1. Frame Fixation

Patient Fixation

Establish Spatial References

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2. Diagnostic Imaging2. Diagnostic Imaging

The coordinate frame provides stereotactic localization

Digital image transfers to the treatment planning computer

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3. Treatment Planning3. Treatment Planning

Team Approach:

The target is defined by the Radiation Oncologist, Neurosurgeon and Medical Physicist.

Care is taken to avoid critical areas of the brain while maximizing the dose to the target.

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4. Treatment4. Treatment

Automatic treatment, supervised by redundant safety and verification systems

Patient communicates via audio visual system

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The Time FactorThe Time Factor

Gamma Knife® Surgery

Several WeeksConvalescence

Open Surgery

Daysin ICU

Weeks ofHospitalization

DiagnosisSymptom

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Clinical OutcomeClinical Outcome

Peer reviewed scientific articles shows better or equal results compared with microsurgery

Reproducible results

Fewer complications

Treatment solution for inoperable patients

Combined treatment with microsurgery and endovasculartechniques extend the capabilities

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Examples of Treated IndicationsExamples of Treated Indications

Vascular- Arteriovenous

malformations

Tumors- Meningioma- Pituitary- Acoustic Neuroma- Metastatic- Gliomas

Functional Targets - Trigeminal nerve

Research Areas- Intractable pain targets- Parkinsonian targets- Psychonuerosis

targets- Epilepsy targets- Other functional

targets

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Arteriovenous MalformationArteriovenous Malformation

Pre-Gamma Knife

Surgery

2 Years Post

Gamma Knife®

Surgery

Courtesy: Douglas Kondziolka, MD, MSc, FRCS, University of Pittsburgh, USA

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• Untreated lesions have a 2-4% risk of bleed per year.

• After Radiosurgery, the risk of bleed remains unchanged until the AVM occludes.

• 80% of lesions treated with Radiosurgery-occlude within 1-3 years following treatment.

• A-V’s amendable to surgery should be resected

Arteriovenous Malformation

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Acoustic NeuromaAcoustic Neuroma

Note: These pictures are provided for education purposes only. Elekta makes no claims as to the effectiveness of the Leksell Gamma Knife ® in these treatments.

2 Years Post Treatment

Pre-Treatment 6 Months Post Treatment

Courtesy: Douglas Kondziolka, MD, MSc, FRCS, University of Pittsburgh, USA

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90% show no further growth after treatment at 10 years.

Tumors that grow slowly respond slowly to Radiosurgery.

Larger tumors greater than 3.0cm should be surgically removed if they are causing acute symptoms from brainstem compression.

Acoustic Neuroma

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Pituitary AdenomaPituitary Adenoma

Courtesy: Ladislau Steiner, MD, PhD, UVA Charlottesville, USA, and Christer Lindquist, MD, PhD, Karolinska Institute, Sweden

Pre-Treatment 54 Months Post Treatment

Note: These pictures are provided for education purposes only. Elekta makes no claims as to the effectiveness of the Leksell Gamma Knife ® in these treatments.

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Tumors compressing the optic chiasm are not appropriate targets for Radiosurgery.

The optic chiasm maximum safe dose tolerance in a single fraction is less than 10 Gy.

The dose necessary to control a Pituitary Adenoma is in excess of 10 Gy.

Pituitary Adenoma

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MetastasisCourtesy: Douglas Kondziolka, MD, MSc, FRCS, University of Pittsburgh, USA

Pre-Treatment 2 Months Post Treatment

Note: These pictures are provided for education purposes only. Elekta makes no claims as to the effectiveness of the Leksell Gamma Knife ® in these treatments.

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Appropriate Lesions for Radiosurgery are: Tumors less than 3cm

Those not associated with a life-threatening mass effect

4 or less tumors simultaneously presenting in the brain with or without whole brain irradiation

Metastasis

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AstrocytomaCourtesy: Ladislau Stenier MD, PhD, Christer Lindquist, MD, PhD and Dheerendra Prasad MD, UVA Charlottesville, USA

Pre-Treatment 5 Years Post Treatment

Note: These pictures are provided for education purposes only. Elekta makes no claims as to the effectiveness of the Leksell Gamma Knife ® in these treatments.

The tumors pattern of spread results in high radiosurgical treatment failures.

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A Globally Embraced TreatmentA Globally Embraced Treatment

202 Leksell Gamma Knife® Installed Worldwide

May 2004

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177846

213718

251681

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78461100532

125227

150982

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1991

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Gamma Knife® Surgery

Cumulative Number of Patients TreatedCumulative Number of Patients Treated

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Quality of LifeQuality of Life

Non-Invasive

Less trauma

Faster recovery

Minimal hospitalization

Fewer complications

Documented Efficacy