DIPG

Biopsy technique

S. PUGET Hopital Necker, Paris

Barcelone 2012

Image Guidance

• Frame-based (stereotactic)

• Frame less (neuronavigation) – No indication for DIPG yet…..

Stereotaxy

• Stereo " tridimensional " and taxis "arrangement »

• Reach any part of the brain with pinpoint accuracy (less than one thousandth of a degree)

• Use of cartesian coordinates

• 2 elements:

– Stereotactic atlas / image-guided

– Stereotactic apparatus

Stereotactic Frame

• Form of a cube or a sphere

• Attached to the patient’s skull

• Coordinates in the 3 axes of space

1st sterotactic frame Contremoulins, 1898

Horsley and Clarke (1918)

Leksell (1951)

Talairach

Todd-Wells (1965)

Reichert (1955)

Stereotactic Principle

Cartesian coordinates in 3D

Stereotactic Procedure

• Local or general anesthesia

• The device is fixed to the skull

• Stereotactic coordinates (entry point & targets)

• Needle placed according the coordinates to reach the target

• Allows to: – Tissue sample

– Remove fluid

– Inject fluid

– Radiosurgery

– Functional Neurosurgery

CED= Convection Enhanced Delivery

• Positive pressure gradient and bulk flow

• Distribution along white matter tracts

• 10 000 fold greater concentration

• Feasability in preclinical models

(Sandberg, Guarnieri, Souweidane..)

• Feasability in a child with DIPG

Lonser 2007

DIPG Diagnosis = Neuroimaging

50% of the pons Hypo CT scan HypoT1- HyperT2 +/- Contrast enhancement

Differential Diagnostics

Peduncles: pilo astro

Pons, exophytic: pilo astro

Hamartoma

bulbo medullary junction: pilo astro

Differential Diagnostics

Atypical aspect

Atypical aspect

Pilocytic astrocytoma

Biopsy Autopsy

• Diagnosis on MRI

• Risk of neurological deterioration

• Small & few samples

• Molecular Profiling AT DIAGNOSIS

• Understand the biology to find target genes

• ……..personalized treatment

• RT and CT can modify biology

• High amount of tissue

• Molecular Profiling

CONS

PRO

Brainstem biopsy

• High degree of accuracy with low operative morbidity

• As safe as stereotactic biopsy of the supratentorial space

ROUTES FOR BRAINSTEM BIOPSY

Routes

Transfrontal

• Precoronal entry

• Long

• All the segments of the brainstem

• Important to avoid ventricles, vessels, tentorium

Transcerebellar

• Through the middle cerebellar peduncle

• Short • Pontine and upper

medullary • Cross less eloquent

structures • Important to avoid the 4th

ventricle and CN nuclei

Transfrontal approach

Transfrontal approach

Transcerebellar approach

Right or left side?

• Depends on the tumor extension & clinical signs

• Choose the most disabled size

• Avoid to add controlateral deficits

HOW TO CHOOSE THE TARGET ?

Target the Contrast Enhancement?

YES

NO

MRI Spectro

Chol

NAA

• Chernov Clin Neurol Neurosurg 2009 Jul – 30 MRI-spectro and 39 MRI. – No significant difference for diagnostic yield

• Not helpful to choose a target

MRI Spectro

MRI Diffusion

Not helpful to choose a target

Diffusion Tensor MRI

JNeurosurg Pediatrics 1:270–276, 2008 Diffusion tensor imaging of brainstem tumors: axonal degeneration of motor and sensory tracts KATHLEENJ. HELTON, M.D.,1JAMESK. WEEKS, M.D.,1NICHOLASS. PHILLIPS, B.A.,1 PINGZOU, PH.D.,1LARRYE. KUN, M.D.,1RAJAB. KHAN, M.D.,1AMARGAJJAR, M.D.,2 MARYAMFOULADI, M.D.,2ALBERTOBRONISCER, M.D.,2FREDERICKBOOP, M.D.,3 CHIN-SHANGLI, PH.D.,4ANDROBERTJ. OGG, PH.D.1

Diffusion Tensor MRI

• 7 children with DIPG / 8 healthy adults • It may help in Planning Biopsies….

PET

• 8 children had both planning • 2 of them had non diag samples in areas of MRI+ / FIDG – • It may help in Planning Biopsies….

ASL

Not helpful to choose a target

TECHNICAL PROCEDURE DIPG biopsy

Leksell frame

Anterior view Posterior view

Lateral view

Leksell frame

1- the frame is fixed on the skull

General anesthesia, referent point post-right, as low as possible

The frame must be fixed as low as possible if not you won’t be able to reach the brainstem

2- the frame is fixed on the CT/MRI table

3- patient positionned according to the CT scan laser beam

4- calculation of the coordinates

Software

Entry point, target point and path

Hands made

Target point

5- transfert in the operating room

Prone position (transcerebellar approach)

Removal of one post pillar

Installation of the whole frame

Burr hole

Installation of the needle support

The biopsy needle

opened

closed

Biopsy Needle introduction

Dorsal position (Transfrontal approach)

Cyst aspiration

Post biopsy MRI

NECKER SERIES

Background

• Dismal Pronostic

• No effective treatment

Biopsies in a part of a trial

Biopsies to find new markers

DIPG biopsy Necker Series

• 90 (2002-2012)

• 4 parents refused

• Number of samples (up to 8)

• No Mortality

• 4 Transient worsening (VII + hemiparesis)

• 2 disseminations along the trajectory at relapse

Serie Necker (at time of analysis)

32 aCGH 23 GE 5 stem cells culture

60 biopsies- 38 frozen

3.3 microg of DNA (range 0.805- 21.5) 2.3 microg of RNA (range 0.048-15.84)

Contrôles Smears

Histological grading

• « DIPG » 6.2%

• Grade II 27.5%

• Grade III 37.5%

• Grade IV 28.8%

Overall Survival (10.5 months) Histological grading

Brainstem gliomas profile (CGH)

1q

14q 10q 17p

2p 7p

CGH: Unsupervised Clustering

Gain/amplif. H-ras PDGFRA & MET Loss PTEN & P53

Gain PARP1

Groupe Proneural / Oligodendroglial

Oligo Olig2

10% mutation PDGFRA (domaine extra cellulaire)

Facteur transcription SOX10

Groupe Mesenchymateux / ProAngiogenique

MT network, Carro et al, Nature 2010

Upregulation of Transcription Factors regulating mesenchymal genes: STAT3, BHLHE40, CEBPA, RUNX1, FOSL2, ZNF238

SNAI1 et SNAI2/Slug

Mes Phenotype: TNC, OSMR, VIM, YKL40/CHI3L1

Vim

Proangiogenic genes: VEGFA, VWF, PECAM1, TREM1, OSMR, PLAU

Stem cells markers

Neurospheres culture and xenograft from DIPG Thiriant et al, PloS One 2011

• Overexpression of stem cell markers

• Overexpression of Mesenchymal markers

« the tumor is heterogeneous, so the biopsy does not reflect the biology of the whole tumor »

Not so sure!!!

DIPG Molecular Biology

• Puget/Grill – Mutations

• 7 patients (Ped blood cancer)

– Genomic • 61 patients (Plos One)

• Louis (JNEN 1993) – 7 patients

• Paugh (JCO 2010) – 7 patients

• Zarghooni (JCO 2010) – 11 patients

• Warren (Neurooncol 2011) – 13 patients

Biopsy Autopsy

• Chromosomal Aberrations

– Gain 1q, 7

– Loss 10q

• Potential targeted therapy

– Gains/Amplifications

• PDGFRA (1/3), MET, PARP1, MYCN, MDM4, AKT3/pI3K, EGFR

– Loss/Deletions

• PTEN, CDKN2A

Séries Autopsies Biologie Moléculaire

• Chromosomal Aberrations

– Gain 1q, 2p, 7p

– Loss 10q, 14q,17p

• Potential targeted therapy

– Gains/Amplifications

• PDGFRA (1/3), MET, PARP1, MYCN, MDM4, AKT3/pI3K, EGFR

– Loss/Deletions

• PTEN, P53, CDKN2A

– Mutations TP53 (40%), PI3KCA (15%), PDGFRA (8.8%)

Série Biopsies Biologie Moléculaire

The BIOlogical MEdicine for DIPG Eradication (BIOMEDE) trial

95

Trial accepted by the French NCI (INCa-PHRC 2011)

If more than one biomarker, dasatinib arm is favored, then mTOR inhibitor If no biomarker identified or blank biopsy, treatment allocated randomly 109 patients (phase I/II for dasatinib and mTOR inhibitor)

Thanks to parents and children who participated in this research, especially to Liv.

CNRS UMR 8203 (IGR): L. Mir, G. Vassal, B. Geoerger, S. Puget, J. Grill, C. Barbosa, V. Scott, E. Daudigos, E. DeCarli, F. Andreiuolo, L. Guerrini-Rousseau, C. Jubert, P. Opolon.

Functional Genomics and Bioinformatics (IGR): C. Philippe, B. Job, C. Richon, P. Dessen, V. Lazar.

Neuropathology (Sainte-Anne Hospital) P. Varlet, C. Miquel

INSERM U752 (Sainte-Anne) H. Chneiweiss, M.P Junier, B. Bessette

CRB Necker S. Dubleumortier, N. Brousse

Neurochirurgie pédiatrique (Necker) S. Puget, C. Sainte-Rose, M.Zerah, T.Roujeau, T. Blauwblomme

Royal Marsden (Sutton) C. Jones, R. Reis, D. Bax, D. Carvalho

Financial Support LEEM recherche, Etoile de Martin, ARNP, INCA-Cancéropole