61. RADIOTHERAPY: CONFORMAL RADIOTHERAPY

Question 1

1. Which aspect can be improved in Conformal Radiotherapy?

Answer 1

• tumour control
• this is accomplished by using special techniques

Question 2

2. What do these special tumour controlling techniques do?

Answer 2

• they deliver a higher dose
• this dose has normal tissue complications that are
  acceptable

Question 3

3. What is Conformal Radiotherapy?

Answer 3

• it conforms the prescription dose volume
• it shapes it to the planning target volume
• this is the tumour

AT THE SAME TIME:
- it keeps the dose below the tolerance dose
- this applies for the specific organs at risk

Question 4

4. What is the Conformal Radiotherapy Chain based on?

Answer 4

1. 3D Target Localisation
2. 3D Treatment Planning
3. 3D Dose delivery Techniques

Question 5

5. How is 3D Target Localisation achieved?

Answer 5

• this is achieved through anatomical and functional
  imaging
• this is because we need imaging applications
• to localise the tumour
• we can use CT-MRI scanners
• these can localise the target in 3 dimensions

Question 6

6. What two techniques do we use for Treatment Planning?

Answer 6

1. Standard Forward Planning Techniques
2. Advanced Conformal Radiotherapy Techniques

Question 7

7. What are Straight Forward Planning Techniques?

Answer 7

• they design uniform intensity beams
• these are shaped to the geometrical projection of the
  target

Question 8

8. What does this image show?

Answer 8

• this is a Straight Forward Planning Technique
• 100% of the total dose is delivered to the Tumour
• this is indicated by the red colour
• there are 5 different beams being used
• each beam delivers about 10 Gy

Question 9

9. What are Advanced Conformal Radiotherapy Techniques?

Answer 9

• they are a form of inverse planning
• they are used in addition to Beam Shaping

Question 10

10. What do Advanced Conformal Radiotherapy Techniques make use of?

Answer 10

• they use intensity modulated beams
• these improve the target dose homogeneity
• they spare the organs that are at risk

Question 11

11. Within Conformal Radiotherapy, what kind of Dose Delivery techniques do we use?

Answer 11

• Standard Regular Beams
• Uniform Coplanar Beams
• Intensity Modulated Non-Coplanar Beams
  (these have multi-leaf collimators)