Lec 1 Contouring

Question 1

What are the difference between serial and parallel structures?

Answer 1

Serial: organ is damaged if one or more subunit is damaged (spinal cord, brainstem, lens)
Parallel: organ will lose function if all subunits are damaged (liver, kidney)

Question 2

What are the margin expansions from GTV?

Answer 2

GTV to CTV to PTV

Question 3

What is a PRV?

Answer 3

planning risk volume

e.g. spinal cord, brainstem, lens

Question 4

What are the main OAR for Pelvis?

Answer 4

bladder 
rectum
small bowel (bowel bag vs individual loops)
Rt and Lt femur
Penile bulb (prostate only)

Question 5

What are the main contours for breast?

Answer 5

Breast CTV
lungs
heart
surgical clips
Internal Mammary Chain

Question 6

What is the PRV margin for spinal cord?

Answer 6

0.5cm

Sp/ Sp cord

Question 7

What is the PRV margin for Spinal Canal?

Answer 7

0.3cm

Sp Canal

Question 8

What is the PRV margin for Brainstem?

Answer 8

0.5cm

BS

Question 9

What is the PRV margin for Lens (L & R)?

Answer 9

0.3cm

Lens

Question 10

What is the PRV margin for optic chiasm?

Answer 10

0.3cm

OC

Question 11

What is the PRV margin for optic nerves (L & R)?

Answer 11

0.3cm

ON

Question 12

What do you need to consider when contouring the brainstem and spinal cord?

Answer 12

important landmark is foramen magnum to differentiate brainstem and spinal cord

Question 13

What needs to be considered when contouring the parotid gland?

Answer 13

consists of superficial and deep part