CNS Oncology & RT Flashcards
how many brain tumours are primary
80%
how many brain tumours are mets
20%
what does survival depend on
guaranteed survival or guaranteed fatality
how many types of brain tumour are there
130
what is the most common type of brain tumour
GBM
where can brain tumours be found
extra-axially and intra-axially
what are brain tumours graded on
genetic findings
PS + fitness
extent of spread
tumour type
location
tumour left after surgery, the amount affects the grade and outcome
what is extra-axial
outside the brain
meningioma, acoustic neuroma
what is intra-axial
inside the brain
glioma
what information enhances treatment options
genetics
what genetics can be looked at
gaining or losing a chromosome, could swap position with other DNA
DNA mark up can change its behaviour
what is MGMT responsible for
cell repair
tumours have a high level, rapid cell repair therefore damage to cell via treatment is less effective
what is EGFR
Epidermal Growth Factor Receptor
protein involved in cell repair
what is IDK
isocitrate dehydrogenase
provides instructions for making a protein involved in cellular metabolism [energy production, cell repair can occur, harder to treat]
what is a seizure
an abnormal electroactivity burst within the brain
how are CNS tumours staged
using the 5th edition of WHO classification
no N stage [TNM IS NOT USED]
molecular grading: low grades can still be aggressive with some molecular subtypes
what are presenting symptoms
fatigue
confusion
sensitivity to light
pain
aching
eye movement issues
heavy body
early/late puberty
nausea & vomiting
balance issues
seizures
changes in head circumference
poor vision
headaches
throbbing head
what are some parietal presentations
visuo-spacial processing issues
knowledge of numbers
spelling
perception issues
object classification
processing info issues, close to the outside of the brain
how are they diagnosed
biopsy not always possible
imaging
MRI
CT [extra-axial]
PET-CT
how is a tumour properly diagnosed
imaging, lumbar puncture, angiography
why is a angiography useful
determines if the tumour has its own blood supply, identify any blockage
however it is unreliable for brain tumours
what is the job of the lumbar puncture
identify if there is any micromets present within the CSF fluid [determine spread]
what are the side effects/ management for CNS
short term memory loss
confusion
loss of fine motor skills
headaches = medication
dizziness
funny smell [irradiated olfactory nerve]
altered PS
vision changes
nausea and vomiting
balance and coordination
seizures = medicine
fatigue
hair loss
how are side effects managed
steroids
anti-convultants i.e keppra
SLT
antisickness
counselling
family support
physiotherapy
consent [Mental Health Capacity Act 2005]
what is the mental capacity act
understand info about decision
remember the info
consider in the decision making process
communicate their decision
what are gliomas
a group of tumours, which arise from glial cells the most common are astrocytes and oligodendrocytes
what are gliomas characterised on
the genetic mutation
DNA mark up is important
what are the types of gliomas
astrocytoma
ogliodendroglioma
gliobastoma
what is an astrocytoma
tumour from astrocyte cells, found in WM, the EGFR is high which promotes tumour growth
what is a grade 1 astrocytoma
pilocytic astrocytoma:
slow growing
cerebellum/optic pathway
well defined edges within capsule
good for surgical removal, low risk of recurrence
occur in <20
what is a grade 2 astro
diffuse astro
undefined edges
20-45
can cause a recurrence, a recurrent grade 2 = grade 3
what is a grade 3 astro
anaplastic:
rapid division
often recur to become grade 4 glioma
30-70
might need a debulking treatment
what is a ogliodendroglioma
occurs from the oligodendrocytes [conductor between neurons]
40-60
2-5% of primary CNS
G1= rare
G2 = slow growing
G3 =. rapid growth
mostly occur on the brain but can be found in the SC
frontal and temporal are the most common lobes
seizures, convulsions, slow motor responses, behavioural changes
what genetic difference does a gliobastoma have
EGFR amplification = 40%
HGG
high grade glioma
LGG
low grade glioma
what are the different types of glioblastoma HGG
IDH wildetype
multiforme
giant cell GB
gliosarcoma
epitheloid GB
how many primary CNS are glioblastomas
54%
have a <2 year prognosis
characteristics of a HGG glioblastoma
significant damage to neurological function
diffuse infiltration to other parts of the brain
frequently crosses midline, involving the contralateral brain
resistant to treatment
HGG grow with an expanding and destructive process
where are patterns for GB found
in the subcortical WM and deep GM of the central hemispheres particularly in the temporal lobe
what is the mandatory criteria for a GBM
16+
diffuse astrocytic
IDH wildetype
what is the criteria that a GBM must have one of
necrosis
microvascular proliferation
TERT promoter mutation
EGER gene amplification
gain 7 chromosome and loss 10 chromosome
where is a primary extra-axial tumour found
outside the cerebrum
what type of tumour is a menigioma
extra-axial
describe a meningioma
slow growing
in the arachnoid layer
25% of primary CNS
presentation occurs when its highly infiltrated intracranially
what is the options for a meningioma
active monitoring
RT for symptomatic patients
surgery
NO chemo as it doesnt respond
why are skull based tumours difficult to treat
sit close to the CNS and brainstem