CT:Glioblastoma Multiforme

1. By
DR TEFFY JOSE
M1 UNIT
PROF RUCKMANI’S UNIT

5. CT scan brain plain study :
An illdefined large hypodense area is seen in the right frontal
region & extending across the midline along the genu of the
corpus callosum.
There is mild mass effect in the form of subfalcine herniation &
squashing of the frontal horn of right lateral ventricle.
Left lateral ventricle is prominent. Midline shift of 4.7mm to
left is seen.
Rest of cerebral parenchyma shows normal attenuation.

All other areas appear to be normal.

6. Impression :
Illdefined large hypodense SOL in the
right frontal region causing mass effect &
midline shift to left.
Suggested CECT / MRI for further
evaluation.

13. MRI scan of brain :
Well defined heterogenously enhancing
mass lesion noted in the right frontal region
basal aspect crossing over to the left frontal
region through the corpus callosum with
areas of necrosis & hemorrhage.
The lesion causing mass effect on the frontal
horn of both lateral ventricles.The mass
lesion measures about 7.8 * 5.6 *4.65 cm.
MR spectroscopy shows increased
lactate,choline peak & reuced NAA levels.
All other areas appear to be normal.

14. Impression :
Features highly s/o GLIOBLASTOMA
MULTIFORME
( butterfly glioma ) involving both frontal
lobes ( Rt > Lt )

15. Glioblastoma multiforme
A diffusely infiltrating astrocytoma ( WHO
2000 classification Grade IV)
Most common form of cerebral glioma
accounting for 12-15 % of all intacranial
neoplasms & 50-60% of all astrocytic
tumors

16. Pathogenesis

Cell of origin

Cell of origin

EGFR amp
LOH 10 (PTEN)
CDK4 amp
MDM2 amp
Other LOH (eg
DCC)
Other amp (eg
PDGFR)

DENOVO
:GBM
WHO grade IV
LOH17p(p53)
Astrocytoma
WHO grade II
LOH19q
LOH9p(INK4a)
Astrocytoma
WHO grade III
LOH 10 q(PTEN)

Secondary : GBM,
WHO gradeIV

17. Rapidly growing tumors, highly cellular,often
provoke a large amount of edema & usually
contain areas of necrosis,& do not have a
clearly defined margin.
Supratentorial, frontal lobes are a common
site of involvement & extension
contralaterally through corpus callosum may
give rise to a butterfly pattern.
May become adherent to the overlying
dura , but seldom penetrate it.
Infiltration of ependyma & dissemination
through CSF pathway may occur in late
cases.
 Multicentricity can be seen in 4-10% of
cases.
Extraneural metastasis are rare.

18. Seen late in adult life, with a peak
occurrence b/w 45 – 60 yrs.
May present with
Seizure
Subacute progression of a focal
neurologic deficit
Nonfocal neurologic disorder such as
headache,dementia, personality change
or gait disorder
Median survival is < 1 yr.

19. MRI features:
High signal intensity on T2 weighted
images & low signal intensity on T1
weighted images
Infiltrate along white matter tracts &
deeper lesions have a propensity to
extend across the corpus callosum to
opposite hemisphere
Often have considerable mass effect,
vasogenic edema& more commonly
show evidence of haemorrhage
Irregular ring enhancement with
nodularity & nonenhancing necrotic foci
is typical of glioblastoma
Microscopic fingers of tumour usually
extend for variable distances beyond the
area of enhancement

20. Management:
Dexamethasone – administered at the
time of diagnosis & continued for the
duration of radiotherapy
Accesible astrocytomas are generally
resected aggressively, even though total
surgical resection is not possible
Post op RT – prolongs survival &
improve quality of life ( 5000-7000 cGy to
tumor mass in 25-35 fractions,
5days/wk)
Role of stereotaxic radiosurgery &
interstitial brachytherapy in glioma trt is
uncertain

21. Chemotherapy
Is marginally effective & is used as an
adjuvant therapy following surgery & RT
Temozolomide , an oral alkylating agent
has replaced nitrosoureas
- 2½ mths longer survival in pts with
methylation & silencing of the promoter
for the MGMT gene
Surgical implantation directly into tumor
resection cavity of polymer wafers that
releases BCNU locally into surrounding
brain

22. Experimental approaches include
- Bypassing BBB using local injections
into tumor mass
- Intraarterial injection of chemotherapy
following osmotic disruption of BBB
Molecular targeted therapies – EGFR
antagonists or inhibitors of its signalling
pathways ( Gefitinib /Erlotinib),
Bevacizumab

23. Prognosis:
- age, functional status,extent of surgical
resection.
- survival ≈ 3 mths (without therapy) , 12
mths (with therapy).
- recurrence is common.