Neurooncology Flashcards
Manifestation of GBM in a case study
Symptoms
Generalized seizure, severe anosognosia, personality change, no deficits in neurological assessment, heterogenous
MRI
Hyperintense patches from gadolinium enhancement
Hyperintense ring shape with a hypointense black center (necrotic pore, no living blood vessles?)
complex, bidirectional relationship between glioma and brain
Manifestation of oligodendroglioma in case study
Symptoms
Seizure, minor cog deficits
MRI
T2 scan to look at edema and infiltration of the tumor into the cortex (hyperintense patch that is larger + diffuse)
Radiology + MRI sequences + tumor manifestation
MRI is gold standard
T1: slight hypointensity (shows anatomy well)
T1+gado: good for GBM as it disrupts the BBB
T2 FLAIR: shows edema infiltration as hyperintense
PET / SPECT / DWI still under scrutiny
Grade I cancer
Meningioma
- homogeneously hyperintense ball after gado enhancement
- Doesnt actually grow into brain tissue eventho it looks like it, connects to outside of brain w/ a small hyperintense tail (indicates its not a GBM)
- Can be surgically removed well + usually doesnt come back
Grade II cancer
Low-grade glioma or astrocytoma and oligodendroglioma
- large tumor with ill-defined boundaries on T1, no or very little contrast enhancement
- larger area of hyperintensity on T2
Grade III cancer
high-grade glioma or anaplastic astrocytoma and oligodendroglioma
- largely identical to grade II, but with more contrast enhancement
Grade IV cancer
glioblastoma multiforme
- Ring-shaped contrast enhancement
- central necrosis
- Lots of edema due to pressure from tumor growing fast
- Multi-focal (may seem separate but usually are connected)
- Tumor cells migrate through WM
- Tumor in frontotemporal lobe tends to cross over to other hemisphere via corpus callosum (midline shift)
Diffuse glioma histology
1) Is there an IDH mutation?
2) If yes Is there a 1p19q chromosomal deletion?
- if yes = oligodendroglioma (best prognosis > 15 yrs)
- if no = astrocytoma
2) If no, check for other criteria + it is probably a glioblastoma (worst prognosis ~ 14 months)
Cancer treatment options
wait & scan
- no treatment, just scan
- only if resection not possible
surgery
– dual optimization: more you can take away longer you can live (trying to optimise 2 things: take away as much tumor as possible whilst trying to keep as much brain (abilities) as possible)
chemotherapy
- BBB is difficult to navigate, chemotherapy ends up not reaching target part
- temozolomide or PCV
radiotherapy
- cant have a very large rim otherwise you will damage healthy tissue
– photon or proton
Vorasidenib
- showed clear survival benefit, targets IDH mutation (occuring early in disease), delays steps in further progression
combination, particularly in GBM
Health-Related Quality of Life
May not only deteriorate, but also improve following treatment
Influenced by treatment and the disease itself
Is subjective by definition
Network theory: types of networks
Regular networks:
- high clustering (C)
- high path length (L)
- every node has 4 connections (made with their direct neighbours)
Random networks
- low C
- low L
Small world
- high C
- low L
Mostly regular but some alternative paths
Any system functioning well is a small world network
Theoretical concepts of networks
Integration: path length
Segregation: clustering, how separate are cliques, modules, clusters etc
Hubness: how many connections does a node have, indicates how important the node is for functioning
Overview of connectomics
diffusion MRI
- raw data: image of brain
- preprocessing: network of brain fibers
- connectivity extration: number/probability of WM fibers
- measures if there is an actual connection
rs-fMRI
- raw data: brain image
- preprocessing: graph
- connectivity extraction: correlation between time series
- measures traffic?
EEG/MEG
- raw data: graph
- preprocessing: graph
- connectivity extraction: correlation between time series
- high temporal resolution can measure very fast changes
- measures brain activity in a more direct way
Glioma and the connectome
Patient network is missing a lot of connections compared to a healthy network
High clustering, local connectivity goes up (counterintuitive but true)
- Relates to seizures
Integration goes down, takes longer for information to reach brain regions because path length is longer
Glioma cells form a network as well that connects to neurons
> Hubs are most important for invasion and aggression of tumor
> glioma cells secrete more glutamate = increases activity and connectivity locally
What are brain tumors
neoplasms arising from different cells within inCNS or from metastasized systemic cancers
Epidemiology
GBM: most common malignant primary brain tumor in adults (~64 years)
Symptoms
headache, seizures, focal deficits, weakness, sensory loss, aphasia, visual-spatial dysfunction, cognitive dysfunction, increased intracranial pressure
Diagnosis
physical and neurological examination
> visual fields, retina, optic discs
brain MRI with contrast
lumbar puncture
biopsy
Second line of treatments
high dose of glucocorticoids to treat edema
anti-sesizure drugs
