stereotactic principles, stereotactic radiosurgery ... · stereotactic principles, stereotactic...

ZHTKiss 2006

Zelma Kiss MD PhDFRCSC

Stereotactic principles,stereotactic

radiosurgery,& functional

neurosurgery

OutlineDefinitions

Principles of stereotaxy: history, frames,imaging, brain atlases

Functional neurosurgery principles

“Frameless” image-guided neurosurgery

Psychosurgery

Principles of stereotactic radiosurgery

ZHTKiss 2003

OutlineDefinitions:Stereotactic: from Greek meaning “to touch” in

“3 dimensions” (termed by the WSSFN at Tokyo meetingin 1973)

Stereotaxic: from Greek meaning “3-darrangement”, original term (coined by Horsley and

Clarke) for animal surgery

Stereotaxis: applies to both human and animaltechniques

ZHTKiss 2003

Outline

Principles of stereotaxy History Frames Imaging Brain atlases

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Principles of stereotaxy: History

1873: Zurzov in Russia encephalometer1906: Horsley & Clarke, 1st primate stereotactic device

(Structure and functions of the cerebellum examined by a new method.Brain 31:45-124, 1908)

1918: Aubrey Mussen, aphysiologist at MNI built 1st

human Stereotactic frame

1920s: Dandy developedventriculography

1931: Moniz developedangiography

Principles of stereotaxy: History

1946: Spiegel & Wycis built the 1st humanstereoencephalatome (Science 106: 349-50, 1947)

1949: Narabayashi built stereotactic frame inJapan

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1949: Leksell built his own system inSweden, 1st arc-centre frame

1949: Talairach built his own systemin France

Many others followed including Riechert(Germany), Guiot (France), Gillingham(UK)

Principles of stereotaxy: Types offrames

Orthogonal–translational

Arc-centredsystem

Burr-holemounted

Interlocking arcsrequiring phantomcheck

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Principles of stereotaxy: Modernframes

Radionics: CRW frameElekta: Leksell stereotactic G-frameRe-locatable frames: Laitinen

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Principles of stereotaxy: Imaging

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Up-down

L-RAnt-post


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What if you cannot see your target?

Schaltenbrand & Bailey 1959Schaltenbrand & Wahren, 1977

Brain atlases

Talairach & Tournaux, 1988

Brain atlases

Brain atlases: Integration with MRI

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Brain atlases: Are they good enough?

How do you relate atlas to your patient? Linear 1-d deformation based on AC-PC line Linear 2-d deformation based on height of thalamus Dynamic warping?

What if your target is 4 x 6 x 6 mm

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AC

PC

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AC PC

STNGPi

Thalamus


Outline

Principles of functional neurosurgeryElectrophysiology = “function”

New attempts to marry imaging andfunction: fMRI, probabalistic atlases,brain warping algorithms

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To marry imaging and function

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Imaging & atlases: Are not goodenough

stereotactic frame placement imaging to determine tentative target physiological monitoring to confirm correct target implant the DBS electrode or make an RF lesion

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Microelectrode methods

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OutlineDefinitions




Psychosurgery


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Principles of stereotaxy: “Frameless”systems

“Image-guided” surgery but all require a “frame” Based on principle of triangulation, relationship

between fiducials/surface contouring imaged, thenwand and star with reflective markers and 2 infraredcameras

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Principles of stereotaxy: “Frameless”systems

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fiducials or surface contouring

reflective markers

infrared cameras

OutlineDefinitions




Psychosurgery


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Prefrontal leukotomyAnterior capsulotomyCingulotomySubcaudate tractotomyLimbic leukotomy

Psychosurgery

History

Egas Moniz:Tentatives opératoiresdans le traitement decertaines psychoses,1936

Nobel Prize, 1947:Prefrontal Leucotomy

10,000 operations pre-1949 in USA

Adapted from A. Abosch 2001

Therapeuticalternatives forpsychotic patientspre-1936

RestraintsImmersion bathsInsulin comaSeizure induction


Outcomes of prefrontallobotomies

Tooth & Newton (1961)N=10,365

70% “improvement”6% mortality1% epilepsy1.5% marked disinhibition

Freeman & Watts:Trans-orbital Leucotomy

“ice-pick procedure”


Fannie Farmer…and other prominent people

who were permanently altered by surgery

One Flew Over the Cuckoo’s Nest, 1958

Societal Disenchantment with Psychosurgery


Chlorpromazine (1952): Delay & Deniker

First neurolepticFirst effective treatment for psychiatric disease


“Modern” Psychosurgery

Refinements instereotactic technique

Refractory OCD &Severe Depressionremain indications


Rationale

1936—Initial report on prefrontal lobotomy(Moniz)

1937—”A Proposed Mechanism of Emotion(Papez)

1952—Limbic system expanded (McLean)Limbic system connects somatic & visceral

stimuli/responses w/higher cortical function


Anatomical Rationale

Fronto-striato-pallido-thalamic-frontal loop

DSM-IV Criteria for OCD

• Presence of either obsessions orcompulsions or both

• These cause marked distress, are timeconsuming (>1 hr/day), significantlyinterfere with normal routine,occupational or academic functioning,or social relationships


Obsessions….

recurrent & persistent thoughts,impulses, or images, intrusive &inappropriate, causing markedanxiety/distress

attempts to ignore/suppress suchthoughts, impulses, images, or toneutralize with other thought or action


Compulsions…

repetitive behaviors (e.g., hand washing,ordering, checking) or mental acts (e.g.,praying, counting, repeating words silently)patient feels compelled to perform in responseto an obsession

behaviors/mental acts are aimed atpreventing/reducing distress or preventingsome dreaded situation; behaviors/mental actsare unconnected w/ what they’re designed toprevent or are clearly excessive


Quantitative OCD Assessment

Yale-Brown OCD Scale (YBOCS)*0-7 Subclinical8-15 Mild16-23 Moderate24-31 Severe32-40 Extreme

A scale to rate severity of OCD

Goodman et al, Arch Gen Psychiarty. 1989; 46:1006-1011

Consider surgery


Treatment of OCD

Majority of patients respond tobehavioral and/or medical therapy:Clomipramine (SRI) & selective serotonin

reuptake inhibitors (SSRIs), e.g. fluoxetine,sertaline

Only small % remain refractory &severely disabled


Criteria for Surgery

Fulfills DSM-IV criteria for OCDSignificant suffering: YBOCS YBOCS ≥≥ 20 20Significant reduction in psychosocial

functioningPatient himself requests surgery,

provides informed consentFailure of adequate trial of therapy


Adequate Trial of Therapy

≥≥ 1010 wks of maximally tolerated dosesof clomipramine & 3-4 SSRIs

Behavioral therapyIn practice ≥≥ 5 5 yrs of intensive

psychiatric treatmentSeries of iv enafranil


Relative Contraindications

Age < 18 yoConcurrent diagnoses, such as

Substance abuseOrganic brain syndromeDelusional disorderPersonality disorderMental retardation

Lack of social support


Preoperative Evaluation

Multidisciplinary Case Review CommitteeNeuropsychiatry, Neurosurgery, Clinical

Psychology, Hospital Ethics, Social WorkAnatomical MRINeurocognitive AssessmentfMRI and/or PET—research tools


Current Procedures

1. Cingulotomy2. Anterior Capsulotomy3. Subcaudate Tractotomy4. Limbic Leucotomy


Cingulotomy

Foltz & White (1962)Target:

20 mm posterior to anterior-most tip of frontal horn

7 mm lateral to midline

Anterior Cingulotomy

Also used in treatment ofpain & major depression

Most commonlyperformed in NorthAmerica for OCD &depression


Ballantine et al., 1987:N=198, mean f/u 8.6 y62% severe affective d/o improved56% OCD improved

Jenike & Baer, 1991:N=33 with OCD25-30% significant improved (YBOCS)

Baer et al, 1995:N=18, 27 m f/uProspective, non-blindedOnly 28% responders (YBOCS)No serious adverse effects


Anterior Cingulotomy: Results

Anterior Capsulotomy

Lars Leksell (1972)

Target: anterior limb of internal capsuleLesion ~18 mm in length5 mm behind tip of frontal horn,

20 mm lateral or halfwaybetween frontal horn tip andforamen of Munro

At level of foramen of MunroAt the border between putamen

and pallidum

Mindus et al, 1997:19 OCD pts, 8.4yrs median f/u (Sweden)47% good outcome19 transient confusion1 seizure1 suicide2 patients slovenlyWeight gain of 10%


Anterior Capsulotomy: Results

Subcaudate Tractotomy

Knight (1964)Stereotactic yttrium

Targetventral to caudate head =

substantia innominata (15mm lat, 10 mm dorsal toplanum sphenoidale)

Intra-operative stimulationproduced autonomicresponses

CC

Goktepe 1975:208 pts mean 2.5 yr f/u68% depressed pts improved50% OCD pts improvedSchizophrenics, personality disorders, substance

abuse patients did poorlySeizures 2.2%Undesirable personality traits 6.7%1 death from hypothalamic destruction3 suicidesNot usually performed in North America


Subcaudate Tractotomy:Results

Limbic LeucotomyKelley et al. (London, 1973)~10 targets within subcaudate +

anterior cingulate regionSCT disconnects OFT pathsAC disconnects Papez

Not commonly performedin North America


Kelley, 1973:N=66, mean f/u 16 m89% of OCD pts improved78% of depressed pts improved80% of schizophrenics improvedlethargy, confusion, lack of sphincter

control common post-op, but resolvesNo post-op seizures


Limbic Leucotomy: Results

Problems with Literature

Previously no standardized rating scale forpre- & post-operative assessment

DSM criteria for diseases have changedsome over the years

No blinding of studies (patients orinvestigators)


Risks of NOT intervening

Suicide risk among patients withrefractory OCD is high

Incalculable loss of psychosocialfunctioning


Psychosurgery: Conclusions

Surgical treatment of refractory OCD can behelpful in ~28% pts, with minimal risks

Optimal target unknownSurgery is only one aspect of the entire

treatment/rehab planPsychosurgery should be performed only at

specialized sites


OutlineDefinitions




Psychosurgery


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What is SRS

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Leksell performed firststereotactic treatment in 1951(linear accelerator-based, withcross-fired arcs), developed theGamma knife in 1968

Proton-beam radiosurgerystarted in 1956

Linac-based radiosurgeryestablished in early 1980s

SRS: Current Indications

Benign Lesions: AVMs Acoustic Neuromas Meningiomas Pituitary adenomas

Malignant Lesions: Metastases Gliomas?

Functional Lesions:Trigeminal neuralgiaEpilepsy ?Chronic pain ?

Single fraction SRS1 extremely high dose of

radiationAblative ~ surgical

excisionMost appropriate for

Arterio-venousmalformations

Benign lesions:acoustic neuromas,pituitary adenomas,meningiomas

Functional targets:trigeminal neuralgia,epilepsy, pain

Fractionated stereotacticradiation therapyMany small doses of

radiation given overmany days

Preferentially spares late-responding i.e. normaltissue resulting in highertherapeutic gain

Equivalent to trueradiation therapy

Most appropriate formalignant tumors

Radiotherapy: Options

Fixed immobilizationdeviceEnsures maximum

precisionSame day planning

performed based onfine cut CT scan +/-MRI scan

Patient treated sameday

Radiotherapy: Singletreatment SRS

The Process: Treatment day

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Relocatable framePlanning based on

fine-cut CT scan +/-MRI scan

Patient comes fordaily treatments overthe course of severalweeks

Radiotherapy: Fractionatedtreatments

Or the target must be huge

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? Radiation beam shaping with micro-multileafcollimator

Novalis

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? Micro-multileaf collimator allows IMRS and IMRT

? High dose rate (800 cGy/min)

? Allows use of fractionation: basic radiobiologyprinciple that improves preservation of normaltissue passing through radiated field (e.g. acoustics,cavernous sinus lesions)

? Use outside the head (e.g. spine)

? On-line X-ray monitoring of patient movement

Novalis

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Novalis

Pre-SRS Sep 2002

Case 1

14 yo male with 1 cm recurrence of craniopharyngioma

Post-SRS Jul 2003

Case 1

14 yo male with craniopharyngioma

Case 2

37 yo male withAVM rupture,Parinaud’s syndrome,hydrocephalus,VP shunt

Case 2

Midbrain AVMSRS Oct 2002

Case 2

Case 2

Midbrain AVMSep 2004

Challenges: Image distortion

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Challenges: Image distortion

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Original angiogram

Correctedangiogram

Challenges: Automaticsegmentation

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Challenges: Body Fixation

stereotactic principles, stereotactic radiosurgery ... · stereotactic principles, stereotactic...

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