P4g-Treatment

Question 1

What are the similarities between x rays and gamma rays?

Answer 1

Both are ionising electromagnetic waves

Both high frequency and have a short wavelength

Question 2

How are gamma rays produced?

Answer 2

They are released from unstable nuclei when they decay

Question 3

How are x rays produced?

Answer 3

By firing high speed electrons at a heavy metal like tungsten

Question 4

Why are x rays easier to control than gamma rays?

Answer 4

Nuclear decay is random so theres no way to control when gamma rays are released

Question 5

How does the image produced by x rays depend on the thickness and density of the absorbing material?

Answer 5

The thicker or denser the material the more x ray thats absorbed.

Question 6

How are medical isotopes produced?

Answer 6

By placing materials into a nuclear reactor

Question 7

What are the uses of nuclear radiation in medicine?

Answer 7

Diagnosis
Treatment of cancer
Sterilisation of equipment

Question 8

Why are gamma and beta radiation used as tracers in the body?

Answer 8

They can penetrate tissue and are able to pass out of the body and be detected

Question 9

Why shouldnt medical tracers remain active in the body for long periods of time?

Answer 9

They can damage living cells

Question 10

How are radioactive sources used to treat cancer?

Answer 10

1. Gamma rays are focused on the tumour using a wide beam
2. Beam is rotated round the patient with tumour at the centre
   This limits the damage to non cancerous tissue

Question 11

How are radioactive sources used as a tracer?

Answer 11

• use a beta or gamma emitter with a short half life
• it can be drunk, eaten, ingested or injected
• allowed to spread through the body
• followed on the outside by a radiation detector