radiotherapy

Question 1

what is ionising radiation?

Answer 1

atoms of natural radioactive substances with unstable nuclei that emit radioactive decay

Question 2

describe gamma rays / x-rays

Answer 2

pass through the skin and are blocked by lead. one of the preferred treatments for radiotherapy

Question 3

describe alpha particles

Answer 3

short range, more damaging - blocked by skin. effective at producing ionisation, preferred treatment for radiotherapy

Question 4

describe beta particles

Answer 4

can pass through skin, and are blocked by aluminium.

Question 5

what is radiotherapy?

Answer 5

the treatment of disease by ionising radiation - it penetrates tissues and alters nuclear material such as DNA by disrupting cell growth and reproduction

Question 6

describe how radiotherapy damages human cells:

Answer 6

by apoptosis. a high energy ray hits a molecule and causes it to break up, this forms free radicals that can cause further damage to the inside of the cell

Question 7

when may radiotherapy be used?

Answer 7

as a stand-alone cancer treatment, to shrink a tumour before surgery, to reduce cancer returning after surgery, palliative therapy - controlling symptoms and reducing pain for untreatable cancers, and to reduce the growth of cells

Question 8

specific use of radiotherapy?

Answer 8

to treat malignancies confided to one area such as the brain, skin, prostate, uterus and breast.

Question 9

what is a ‘fraction’

Answer 9

the term used to describe each exposure of radiotherapy treatment

Question 10

describe external radiotherapy?

Answer 10

supplied from outside of the body, given over several days/weeks, painless procedure that lasts 5 minutes per fraction

Question 11

describe internal radiotherapy?

Answer 11

brachytherapy - utilizing radioactive implants placed inside the body - radioactive seeds or wires are put in the affected area, given once or a few times

Question 12

administration of internal radiotherapy?

Answer 12

IV or liquid form

Question 13

general side effects of radiotherapy?

Answer 13

tiredness, nausea and vomiting, sore skin, muscle and joint pain, infertility

Question 14

what is the risk of radiotherapy?

Answer 14

increased dose means a slight increase in risk to normal cells, could cause cancer

Question 15

how is radiotherapy used in graves disease?

Answer 15

reduces the activity of the thyroid gland by destroying cells, and causing less T3/T4 release

Question 16

examples of research into future radiotherapy treatments?

Answer 16

hyper/hypo-fractioned radiotherapy, stereotactic radiotherapy, proton and ion beam radiation

Question 17

describe hyper-fractioned radiotherapy

Answer 17

increasing frequency of fractions; treatment over 12 days rather than 4-6 weeks.

Question 18

describe hypo-fractioned radiotherapy?

Answer 18

increasing dose of radio per fraction, reducing the frequency of fractions - overall less radiotherapy exposure