Radiotherapy & Chemotherapy for CNS Tumours

Question 1

CNS tumours account for what percentage of cancers?

Answer 1

~3%

Question 2

What are the 4 main indications for oncology in terms of CNS tumours?

Answer 2

1) High grade glioma (esp. Glioblastoma)
2) Low grade glioma
3) Benign tumours
4) Paediatric

Question 3

Name 3 paediatric CNS tumours?

Answer 3

1) Medulloblastoma
2) Germ cell
3) Ependymoma

Question 4

Name 3 benign CNS tumours?

Answer 4

1) Meningiomas
2) Pituitary adenomas
3) Schwannomas

Question 5

What are the 3 main features on presentation with a CNS tumour?

Answer 5

1) Pressure symptoms - headache, confusion, reduced conscious level
2) Seizures (50%)
3) Focal symptoms due to location (eg. weakness, dysphasia)

Question 6

What 2 features together are indication for a scan to investigate a CNS tumour?

Answer 6

Headache + neuro sign/symptom

Question 7

What are the 5 types of possible treatment for CNS tumours?

Answer 7

1) Steroids
2) Anti-epileptics
3) Surgery
4) Radiotherapy
5) Chemotherapy

Question 8

What are the 3 main adverse effects of steroid treatment for CNS tumours which can lead to reduced self esteem?

Answer 8

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

Question 9

Why can anti-epileptic drugs be difficult to use in treatment of CNS tumours?

Answer 9

Have a lost of side effects and interact with other drugs eg. can cause sedation and mood disorders

Question 10

Which hemisphere is concerned with language?

Answer 10

The dominant hemisphere - this is the left hemisphere in most people

Question 11

When a patient presents with changes to the personality becoming apathetic and bad tempered, where is the lesion most likely to be?

Answer 11

Frontal region

Question 12

A lesion in the parietal lobe would be associated with what 3 main features?

Answer 12

1) Sensory loss
2) Dyspraxia
3) Inattention

Question 13

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?

Answer 13

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

Question 14

Why is there a big advantage to using protons in children?

Answer 14

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

Question 15

Give the 3 acute side effects of cranial radiotherapy?

Answer 15

1) Cerebral oedema causing raised ICP and exacerbation of pre-RT neurological symptoms
2) Hair loss
3) Scalp/ear erythema

Question 16

What are the 2 main intermediate side effects (within a few weeks/few months) of cranial radiotherapy?

Answer 16

Somnolence syndrome (severe tiredness) and exacerbation of existing neurological symptoms

Question 17

What are the main late effects (several months to years after RT) of cranial radiotherapy?

Answer 17

Damage to sensitive structures (shield these from radiation as much as possible) eg.
lens (cataracts)
Pituitary (hypopituitarism)
cerebral hemispheres (memory loss)

Question 18

In which situation is radiotherapy for high grade gliomas (grade 3/4) recommended?

Answer 18

In young and fit people who could live for several years after RT

Question 19

In which situation is RT for high grade gliomas (grade 3/4) not recommended?

Answer 19

If elderly or poor prognosis - may die of brain tumour within 3/12s, before recovered from the side-effects of RT

Question 20

What is the median treatment outcome for the 4 grades of glioma?

Answer 20

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

Question 21

Treatment can be curative for what 2 rare CNS tumours?

Answer 21

1) Germ cell tumours

2) Medulloblastomas

Question 22

When would you use chemotherapy be used to treat brain metastases?

Answer 22

If the primary tumour is chemosensitive eg. small cell lung cancer

Question 23

Can radiotherapy be used to treat brain metastases?

Answer 23

Yes sometimes whole brain RT

Question 24

In which 2 ways can chemotherapy be used in the treatment of CNS tumours?

Answer 24

1) Can be used palliatively

2) Can also be used to enhance the effectiveness of radiotherapy

Question 25

What are the 3 current trends in treating CNS tumours?

Answer 25

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