57. RADIOTHERAPY: TREATMENT MACHINES FOR RADIOGRAPHY

Question 1

1. Which factors can be controlled in Radiotherapy?

Answer 1

1. Means of delivering the Radiation
2. Radiation type
3. Total dose
4. Fractions into which the total dose is divided
5. Time between fractions

Question 2

2. What are 2 essential issues in Radiation Therapy?

Answer 2

1. The type of particle used
2. The energy of the particle

Question 3

3. What kind of particles should the tumour absorb energy from?

Answer 3

• Radiation particles

Question 4

4. How are Alpha particles flawed when it comes to their use in Radiotherapy?

Answer 4

• they have a very short range
• they are very heavy
• this prevents them from reaching the diseases region

Question 5

5. How are Neutrons flawed when it comes to their use in Radiotherapy?

Answer 5

• they require a nearby nuclear reactor
• to produce them

Question 6

6. Which type of Radiation particles are currently used in most therapies?

Answer 6

• high energy photons
• the Beta Negative particles

Question 7

7. What are three alternative approaches for delivering Ionising Radiation to the patient during therapy?

Answer 7

1. Beam Sources that are external to the body
2. Brachytherapy Sources
3. Unsealed Sources

Question 8

8. What happens when we use Beam sources that are external to the body?

Answer 8

• they produce a beam of ionising radiation
• this is aimed at the tumours
• this happens during treatment sessions

Question 9

9. What happens when we use Brachytherapy sources?

Answer 9

• sealed radioactive sources are placed in proximity with
  the tumour
• they can be inside the tumour
• or they are extremely close to it

Question 10

10. What happens when we use Unsealed sources?

Answer 10

• Radionuclides are taken into the body in liquid form
• this can happen through an injection
• or by swallowing

Question 11

11. Which alternative method for delivering ionising radiation is the most widely used?

Answer 11

• The method that makes use of:
  Beam sources that are external to the body

Question 12

12. What kind of beam does the Beam Source method deliver?

Answer 12

THE BEAM IS:
- uniform
- well defined
- stable

Question 13

13. What is preselected when it comes to the Beam Source method?

Answer 13

• the particles are pre-selected
• they have top have the correct penetration depth
• as per the needs of the individual case

THIS ENSURES THAT:
- the beam reaches only the regions intended
- that the beam delivers the desired dose

Question 14

14. What is the aim of the machinery used in Radiotherapy?

Answer 14

THE AIM IS RO PRODUCE:
- very high photon and electron beam energies
- with very high intensities

Question 15

15. What kind of methods of Radiotherapy have we made use of over the last 25 years?

Answer 15

• Computerisation
• Intensity Modulated Beam Delivery

Question 16

16. What discovery provided a tremendous boost in the field of Radiotherapy?

Answer 16

• the discovery of 60 Co
• this is a Radioactive source
• it emits Gamma rays when it decays