Radiotherapy & Chemotherapy for CNS Tumours Flashcards
CNS tumours account for what percentage of cancers?
~3%
What are the 4 main indications for oncology in terms of CNS tumours?
1) High grade glioma (esp. Glioblastoma)
2) Low grade glioma
3) Benign tumours
4) Paediatric
Name 3 paediatric CNS tumours?
1) Medulloblastoma
2) Germ cell
3) Ependymoma
Name 3 benign CNS tumours?
1) Meningiomas
2) Pituitary adenomas
3) Schwannomas
What are the 3 main features on presentation with a CNS tumour?
1) Pressure symptoms - headache, confusion, reduced conscious level
2) Seizures (50%)
3) Focal symptoms due to location (eg. weakness, dysphasia)
What 2 features together are indication for a scan to investigate a CNS tumour?
Headache + neuro sign/symptom
What are the 5 types of possible treatment for CNS tumours?
1) Steroids
2) Anti-epileptics
3) Surgery
4) Radiotherapy
5) Chemotherapy
What are the 3 main adverse effects of steroid treatment for CNS tumours which can lead to reduced self esteem?
1) Make you put on weight in the face and around the middle
2) Make you lose muscle mass in your legs
3) Affect sugar metabolism
Why can anti-epileptic drugs be difficult to use in treatment of CNS tumours?
Have a lost of side effects and interact with other drugs eg. can cause sedation and mood disorders
Which hemisphere is concerned with language?
The dominant hemisphere - this is the left hemisphere in most people
When a patient presents with changes to the personality becoming apathetic and bad tempered, where is the lesion most likely to be?
Frontal region
A lesion in the parietal lobe would be associated with what 3 main features?
1) Sensory loss
2) Dyspraxia
3) Inattention
What is the difference between protons and photons when used to treat brain tumours in terms of low dose beams to the rest of the brain?
With protons get much less low dose radiation to the rest of the brain - more focused
With photons get much more low dose radiation to the rest of the brain - less focused
Why is there a big advantage to using protons in children?
Children are more likely to survive so it is important to get less low dose radiation to the brain as this may affect them in the future
Give the 3 acute side effects of cranial radiotherapy?
1) Cerebral oedema causing raised ICP and exacerbation of pre-RT neurological symptoms
2) Hair loss
3) Scalp/ear erythema
What are the 2 main intermediate side effects (within a few weeks/few months) of cranial radiotherapy?
Somnolence syndrome (severe tiredness) and exacerbation of existing neurological symptoms
What are the main late effects (several months to years after RT) of cranial radiotherapy?
Damage to sensitive structures (shield these from radiation as much as possible) eg.
lens (cataracts)
Pituitary (hypopituitarism)
cerebral hemispheres (memory loss)
In which situation is radiotherapy for high grade gliomas (grade 3/4) recommended?
In young and fit people who could live for several years after RT
In which situation is RT for high grade gliomas (grade 3/4) not recommended?
If elderly or poor prognosis - may die of brain tumour within 3/12s, before recovered from the side-effects of RT
What is the median treatment outcome for the 4 grades of glioma?
Grade 1) Many years - cured if complete resection
Grade 2) 5-12 years - depending on type
Grade 3) 2-4 years - depending on type
Grade 4) 6-18 months - depending on prognostic factors
Treatment can be curative for what 2 rare CNS tumours?
1) Germ cell tumours
2) Medulloblastomas
When would you use chemotherapy be used to treat brain metastases?
If the primary tumour is chemosensitive eg. small cell lung cancer
Can radiotherapy be used to treat brain metastases?
Yes sometimes whole brain RT
In which 2 ways can chemotherapy be used in the treatment of CNS tumours?
1) Can be used palliatively
2) Can also be used to enhance the effectiveness of radiotherapy
What are the 3 current trends in treating CNS tumours?
1) molecular sub calssification of tumour types (more accurate prognosis and predictive information)
2) Novel targets for treatment (eg. angiogenesis, cell adhesion molecules, oncogenic pathways)
3) Immunotherapy and viral therapy
