Radiotherapy

Question 1

Who administers radiotherapy

Answer 1

Radiographers

Clinical oncologists

Question 2

What type of ionising radiation is used in radiotherapy

Answer 2

Electrons
Photons - Xrays
Proton beams

Question 3

Types of radiotherapy machine

Answer 3

Linear particle accelerators - electrons and photons

Cyclotrons - proton beam therapy

Question 4

Action of radiotherapy

Answer 4

Direct - DNA damage causing cell death

Indirect - Radiation ionises water molecules which produces free radicals that damage DNA causing cell death

Question 5

Types of radiotherapy

Answer 5

External beam (most common)
Brachytherapy
Radioactive substance injected e.g. iodine radioisotope

Question 6

Brachytherapy features

Answer 6

Used as a boost treatment or primary treatment

Radiotherapy delivered locally so less side effects

Question 7

Which cancers are brachytherapy used in

Answer 7

Prostate and cervical

Question 8

Which cancer used radioactive substance injections

Answer 8

Thyroid cancer

Question 9

Aim of radiotherapy

Answer 9

Deliver the highest dose possible to the tumour whilst minimising the dose to normal tissue

Question 10

Mechanism of external beam radiotherapy

Answer 10

Several beams of radiation converge on tumour target

Intensity and shape of the beam can be modulated by multileaf collimators

Question 11

Patient journey for radiotherapy

Answer 11

1. CT or MRI scan for planning
2. Simulator
3. Pre-treatment calculations made
4. Linear accelerator
5. Onboard imaging

Question 12

How long does the radiotherapy process take

Answer 12

Up to 28 days from referral to treatment

Question 13

What are radiosensitisers

Answer 13

Low dose chemotherapy to make tumour cells more prone to damage

Question 14

Purpose of neoadjuvant radiotherapy

Answer 14

Shrink tumour size before surgery to facilitate clear surgical margins

Question 15

Benefits of neoadjuvant radiotherapy

Answer 15

Reduction in post-op regional recurrence
Reduction in distal metastasise
Improve long term survival

Question 16

Chemoradiation

Answer 16

Neoadjuvant or adjuvant radiation often given with chemotherapy to increase benefits but side effect profile is more severe

Question 17

When is adjuvant chemotherapy given?

Answer 17

When risk of regional cancer recurrence is higher due to :

• positive or close surgical margins
• lymph node involvement
• high grade tumour

Question 18

Which cancers can be cured by chemoradiation?

Answer 18

Head and neck
Cervical
Bladder
Anal

Prostate cancer - radiotherapy and hormone therapy

Question 19

Fractions

Answer 19

Balance tumour cell death with normal cell death therefore given in sessions

Question 20

Indications for palliative radiotherapy

Answer 20

Tumour related bleeding
Tumour related pain
Pressure symptoms due to tumour - spinal cord compression/ SVCO

Question 21

Risks of radiotherapy

Answer 21

Works in 60% of cases
May take 4 - 6 weeks
May worsen tumour-related symptoms - temporary oedema due to inflammation

Question 22

Early side effects of radiotherapy

Answer 22

Fatigue 
Hair loss 
Nausea and vomiting 
Dysphagia 
Oral mucositis 
Radiation cystitis
Diarrhoea 
Low blood counts

Question 23

Late side effects

Answer 23

Pneumonitis - breathlessness
Lung fibrosis

Heart cardiomyopathy and pericardiofibrosis

Bowel strictures and adhesions/ fistulas

Dermatitis - erythema
Lymphoedema

Sterility
Bone fractures

Cataracts/ loss of sight

Mouth ulcers/ dry mouth