Radiotherapy Flashcards
How does radiotherapy work?
Ionising radiation can penetrate tissues and alter the nuclear material, causing apoptosis.
When a high-energy ray hits a molecule, it can cause it to break up, forming free radicals which cause further damage to the inside of the cell
Which types of radiation are used to treat malignancies?
Alpha and gamma radiation
they are more likely to cause tissue or cell damage
In cancer treatment, what is radiotherapy used for?
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 and is no longer treatable
To reduce the growth of cells (Graves disease)
What are the different types of radiotherapy?
External -supplied from outside the body
Internal -radioactive implants are placed inside the body
What is radiotherapy?
The treatment of disease by ionising radiation
How is external radiotherapy delivered?
Usually over several days or weeks
Mon-Fri with the weekend off
Target area is marked
Patient lies motionless in a certain position
Each fraction lasts around 5 minutes
What is conformal radiotherapy?
The use of metal blocks to direct the beam of ionising radiation, so that the shape of the tumour is more closely targeted
Routinely used for prostate cancer
How is internal radiotherapy delivered?
Given once or only a few times
Usually involves hospital stay
Radioactive wires or seeds are put into the affected area for a few days
Small amounts of ionising radiation are placed in the tumour permanently which will degrade over time
What are the main radioactive elements used in internal radiotherapy?
Strontium 89
Samarium 153
Iodine 131
Radium 223
What are the side effects associated with radiotherapy?
Tiredness
Anaemia
Diarrhoea
Nausea and sickness
Loss of appetite
Sore skin
Temporary hair loss at radiation site
Muscle and joint pain
Loss of libido
Early menopause in women
Impotence/infertility in men
What is hypofractionated radiotherapy?
Radiotherapy that is given in fewer fractions, with an increased dose of radiotherapy per fraction
There is an overall reduction in the total amount of radiation received
What is stereotactic radiotherapy?
Radiotherapy used to treat small round tumours usually found in the head
Pituitary adenomas
Acoustic neuromas
Meningiomas
Secondary brain tumours (Gliomas)
How is radiotherapy used to treat Graves’ disease?
By reducing the activity of the thyroid gland by destroying the cells, leading to less T3/T4 release
What is hyperfractionated radiotherapy?
Radiotherapy given in increased fractions -more than one a day
Treatment given over 12 days rather than 4-6 weeks
Total dose is the same
