Plan Optimisation and Evaluation

Question 1

what does the RO prescribe?

Answer 1

Total dose
fractionation
Point or volume dose
indicative energy
overall treatment time

Question 2

what does the dose prescription rely on?

Answer 2

intrinsic radiosensitivity
department protocols
international protocols

Question 3

how to prescribe a reference point?

Answer 3

Assign to centre of planning target volume
can coincide with isocentre position
tell TPS which beams are attached to prescription

Question 4

what is normalisation?

Answer 4

dose expressed as a percentage of dose to a reference point

generally 100%

Question 5

principles of optimisation?

Answer 5

lowest dose to critical tissues
fufill plan prescriotion
efficient

Question 6

what is field based planning?

Answer 6

old techniques

Not very conformal

Question 7

what is volume based planning?

Answer 7

current techniques using Ptv volumes
port generated for PTV
margin for beam penumbra 0.6cm

Question 8

beam energy choices?

Answer 8

6,10,15,18MV

6,9,12,15 electrons

Question 9

what is co-planar?

Answer 9

couch at zero

Non co-planar colliamtor shifts