Radiotherapy Flashcards
What is the nucleus of atoms made up of?
Neutrons and protons
What are atoms made up of?
Neutrons, protons and electrons
What are the 4 types of radiation?
Alpha, beta, gamma/x-rays, neutrons
What stops alpha waves?
Skin
What stops beta waves?
Aluminium
What stops gamma/x rays?
Lead
What stops neutrons?
Concrete
Give 5 examples of how radiation is used
Smoke detectors Sterilising medical instruments Dating rocks and materials - archaeological finds Traces for medical diagnosis Killing cancer cells
What is radiotherapy?
The treatment of disease by ionising radiation.
How does ionising radiation work?
Penetrate tissues, alters the nuclear material i.e DNA, disrupting cell growth and reproduction. Causes apoptosis.
What is the advantage of radiotherapy?
Targeted to damage cancer cells - healthy cells can recover.
What types of radiation are the preferred treatment?
Alpha and gamma radiation
When might you use radiotherapy? (5 reasons)
To treat cancer To shrink a tumour before surgery To reduce cancer returning after surgery To control symptoms - palliative To reduce growth of cells - Graves' disease
When would radiotherapy be appropriate and when wouldn’t it be appropriate?
Appropriate for stand alone tumours, can target a specific area. Not appropriate if cancer has spread.
What are the two types of radiotherapy?
External and internal
How long does it take to give external radiotherapy?
Usually given over several weeks, mon-fri. 5 min per fraction.
What is important to remember when giving radiotherapy?
Mark the area, person needs to be motionless during treatment.
What is a radiotherapy machine?
Metal element is heated to produce electrons, these accelerate in an electric field towards a piece of tungsten metal which emits high energy x rays when they hit it.
What is conformal radiotherapy (CRT) and when is it used?
Use of metal blocks to direct the beam of ionising radiation to target the shape of the tumour - used in prostate cancer.
What is internal radiotherapy?
Radioactive wires or seeds put into affected area, may be given once or a few times, usually in hospital, a few days (wires or IV), monitored using a Geiger counter, mustn’t come into contact with pregnant women or anyone growing.
When might you use internal radiotherapy?
Cervical cancer
Which radiation do you use for internal radiotherapy?
Alpha
How can you give internal radiotherapy?
IV or liquid form
Name two forms of internal radiotherapy given for bone cancer?
Strontium 89 and samarium 153
When would you use iodine 131?
On the thyroid gland
What is the name of a radiotherapy being used in secondary bone cancer trials?
Radium 223
Other than for secondary bone cancer when else might you use radium 223?
Relieve blockages of the oesophagus
Why might people experience side effects to radiotherapy?
Damage to healthy cells can take time to recover
What do the side effects of radiotherapy depend on?
Area being treated. Dose of radiation. Age Ca for longer period Physical well being
When can side effects of radiotherapy appear?
During treatment.
Weeks/months after treatment
Give 5 side effects of radiotherapy
Tiredness Nausea/sickness Sore skin Muscle and Joint pain Fertility
Why might radiotherapy cause tiredness?
Physical exertion of going every day Anaemia - destruction of RBC's Less 02 carrying capacity Diarrhoea Bone marrow affected - pelvis, abdo, prostate.
Which areas receiving radiotherapy might cause sickness?
GI tract and brain
Why does radiotherapy cause sickness when targeting the brain?
Triggers vomiting centre
What might you prescribe for someone who is suffering from sickness?
Anti emetics eg domperidone
What are people advised not to use when receiving radiotherapy for breast cancer?
Deodorant or perfumed soaps
Why do people relieving radiotherapy suffer from sore skin?
Local reaction to the radiation, temporary hair loss in area.
What can help ease muscle and joint pain?
Light exercise/physiotherapy
What three different things can cause fertility problems in those receiving radiotherapy?
Loss of libido
Ovarian function affected inducing early menopause
Prostate impotence/infertility
What is a risk of radiotherapy?
Could cause cancer in normal cells
Why would you use radiotherapy in the thyroid gland?
Graves’ disease - reduce activity of the thyroid gland by destroying cells, less T3/T4 release.
Current research is looking into what two types of radiotherapy?
Hyperfractionated
Hypofractionated
What is hyper fractionated radiotherapy?
More than one fraction a day given over 12 days
What is hypo fractionated radiotherapy?
Increase dose of radiotherapy but give over fewer fractions
What is stereotactic radiotherapy?
Used to treat small round tumours of head, eg pituitary adenomas, acoustic neuromas, growths in the base of the skull - meningiomas
What is radiosurgery?
One single large dose of radiation, only suitable for small tumours, IMRT and IGRT.
