Radiotherapy

Question 1

What is radiation?

Answer 1

atoms are made up of neutrons, protons and electrons

stability: protons = electrons

Question 2

What is ionising radiation?

Answer 2

can be:
electromagnetic waves eg. x-rays/gamma rays (gamma most penetrative)
alpha and beta particles
= radiotherapy
ionising radiation can penetrate tissues and alter the nuclear material eg. DNA disrupting cell growth and reproduction
damaging human cells = apoptosis = release of free radicals = further damage to cell
- healthy cells can recover
- used to treat malignancies

Question 3

What is the most preferred treatment?

Answer 3

alpha and gamma radiation are more likely to cause tissue/cell damage
= preferred treatment in comparison to beta

Question 4

Why might radiotherapy be used?

Answer 4

• to treat cancer as a stand alone treatment
• to shrink a tumour before surgery
• to reduce cancer returning after surgery
• to control symptoms/reduce pain if cancer has progressed/no longer treatable (palliative)
• reduce growth of cells in Grave’s disease
  specifically used to treat malignancies confined to one area eg brain, skin, prostate, breast, uterus

Question 5

Types of radiotherapy

Answer 5

external:
- supplied from outside the body
internal:
- utilizing radioactive implants placed inside the body
each exposure of radiotherapy is termed as a ‘fraction’

Question 6

External radiotherapy

Answer 6

usually given over several days/weeks
mon-fri with the weekend off
mark target area - therefore need to lie in a certain position (motionless)
- 5mins per fraction
- painless

Question 7

Conformal radiotherapy (CRT)

Answer 7

3D CRT
used of metal blocls to direct the beam of ionising radiation
more closely targets the shape of the tumour
routinely used for prostate cancer

Question 8

Internal radiotherapy

Answer 8

also known as ‘brachytherapy’
- may only be given once/ few times
- involves stay in hospital
- radioactive wires/seeds put into affected area
- a few days = wires/i.v
- permanent = small amounts of seeds of ionising radiation placed in tumour, degrade over time
= radioactivity monitored by a Geiger counter
> may have to limit contact with people
- can be given i.v/liquid form
eg. Strontium 89/ Samarium 153 (bone cancers)
Iodine 131v (thyroid gland)
Radium 223 (secondary bone cancer)
- can also be used to relieve blockages of the oesophagus

Question 9

What causes the side effects of radiotherapy

Answer 9

caused by damage to healthy cells
dependent on area being treated, dose and physical wellbeing at time of treatment
can appear during treatment or weeks/months after

Question 10

Tiredness

Answer 10

Physical exertion of going for treatment every day
Anaemia - destruction of erythrocytes
Less O2carrying capacity
Extreme cases may require transfusion
Bone marrow affected – pelvis, abdomen, prostate
Diarrhoea

Question 11

Nausea and sickness

Answer 11

Depends on area receiving treatment eg GI tract, brain
Some people feel sick at beginning, during, post treatment
Alter diet
Prescribe anti-emetics i.e. Domperidone
Dexamethasone, 5HT antagonists, anti-histamines
Loss of appetite

Question 12

Sore skin

Answer 12

Local reaction to the radiation
Sore and red – avoid irritants
Temporary hair loss in area

Question 13

Muscle and joint pain

Answer 13

Treatment may cause muscle stiffness in affected area
Swelling of joints
Light exercise/physiotherapy helps

Question 14

Fertility

Answer 14

Loss of libido (tiredness)
Pelvic area- may affect ovarian function in women-induce an early menopause causing infertility
Prostate –impotence/infertility

Question 15

Radiotherapy and thyroid gland

Answer 15

grave’s disease

reduce activity of thyroid gland by destroying cells = less T3/4 release

Question 16

Hyperfractionated radiotherapy

Answer 16

increasing frequency of fractions more than once a day
treatment given over 12 days rather than 4-6weeks
total dose the same
requires a hospital stay

Question 17

Hypofractionated radiotherpay

Answer 17

increase dose of radiotherapy per fraction but lower frequency of fractions
overall reduction in total amount received
assess reduction in SE and reduction in risk of recurrence of cancer

Question 18

Stereotactic radiotherapy

Answer 18

used to treat small round tumours usually found in the head
Used to treat a number of benign conditions:
Pituitary adenomas
Acoustic neuromas
Growths at the base of the skull (meningiomas)
- secondary brain tumours or Gliomas
- treatment delivered from many different points in the head
- external frame to keep head in place.

Question 19

Radiosurgery

Answer 19

a type of stereotactic radiotherapy
patients receive one single large dose of radiation
may be used if patients can’t undergo surgery
not suitable for medium or large tumours dueto consistency of exposure
damage to nerves

Question 20

Proton and ion beam radiation

Answer 20

utilizes streams of proton particles, which focus more tightly on tumours compared to radiotherapy = more normal tissue is spared
good when tumour is in a sensitive area eg. brain/ when a child is developing
utilises proton beams instead of ionising radiation
large dose = reduction in SE