Radiotherapy

Question 1

What is Radiotherapy?

Answer 1

The treatment of disease by ionising radiation.

Question 2

How does Radiotherapy work?

Answer 2

Targeted to damage cancer cells.

Apoptosis; high-energy ray hits a molecule causing it to break and form free radicals.

Question 3

Uses of Radiotherapy…

Answer 3

Treat Cancer
Shrink tumour pre-surgery
Reduce cancer returning post-surgery
Control symptoms / Reduce pain of progressive cancer
Reduce growth of cells E.g. Graves Disease
Palliative radiotherapy

Question 4

Treats malignancies confined to one area…

Answer 4

Brain, Skin, Prostate, Breast, Uterus

Question 5

External Radiotherapy…

Answer 5

Supplied from outside the body, given over several days/weeks - painless.
Mark a target area, lie motionless, 5 minutes per fraction.

Question 6

Internal Radiotherapy…

Answer 6

Utilising radioactive implants inside the body; radioactive wires/seeds (gold/iodine).
Can also relieve oesophagus blockage.
Strontium 89, Samarium 153, iodine 131 (thyroid), radium 223

Question 7

Mechanisms of a Radiotherapy machine…

Answer 7

Metal element heated to produce electrons > accelerate in electric field towards tungsten metal > emits high-energy x-rays.

Question 8

Causes of Side effects of Radiotherapy…

Answer 8

Damage to healthy cells: depends on area treated, radiation dose and physical wellbeing.

Question 9

Conformal Radiotherapy (CRT)…

Answer 9

Use of metal blocks to direct beam of ionising radiation, closely targets shape of tumour.
Routinely used for prostate cancer.

Question 10

Radiotherapy induced tiredness…

Answer 10

Physical exertion going for treatment daily, Anaemia, Bone marrow affected, diarrhoea.

Question 11

Radiotherapy induced nausea…

Answer 11

GI tract / Brain treated.

Resolve by; altering diet, anti-emetics, Dexamethasone, 5HT antagonist and anti-histamine.

Question 12

Radiotherapy induced sore skin…

Answer 12

Local reaction to radiation; sore and red - temp hair loss.

Question 13

Radiotherapy induced muscle/joint pain…

Answer 13

Muscle stiffness in treated areas, joint swelling.

Resolve with exercise and physio.

Question 14

Effect of radiotherapy on fertility…

Answer 14

Loss of libido, ovarian function if pelvic treated, induce early menopause. Prostate treatment > impotence/infertility.

Question 15

Hyperfractioned radiotherapy…

Answer 15

Increased frequency, over 12 days, total dose the same.

Question 16

Hypofractioned radiotherapy….

Answer 16

Increased dose but fewer fractions. Reduction in radiotherapy received.

Question 17

Stereotactic radiotherapy…

Answer 17

Treat small round tumours usually in the head, benign: Pituitary adenomas, acoustic neuromas, meningiomas.

Radio surgery = one large dose, IMRT IGRT

Question 18

Mechanisms of Proton/Ion beam radiation…

Answer 18

Utilises steam of proton particles, focus more tightly on tumours.
Works well on sensitive tumours & Children.
Tested on spinal cord, prostate, lung and liver.