treatment planning: ICRU 62

Question 1

reference points

Answer 1

internal or external alignment, points or lines used to establish to a patients co-ordination system and fro a reproducible alignment of a patient for imaging and tx

Question 2

internal reference points

Answer 2

anatomical landmarks eg. bony structures

Question 3

external reference points

Answer 3

palable or visual references points on or near the bodys surface

skin markings or alignment tattoos

Question 4

Co-ordinate system related to the patient: defined as

Answer 4

one of the reference points as the origin

another for orientation of system and alignment of patient

Question 5

Co-ordinate system related to the patient: defined with

Answer 5

the respect to the gantry, collimators rotation beam and couch top system

Question 6

Internal Margin

Answer 6

take into account the shape , size and CTV in relation to anatomical reference points

Question 7

Set-up Margin

Answer 7

takes into account all the uncertainties in patient beam position

Question 8

Internal Target Volume (ITV)

Answer 8

CTV w margin to compensate for expected physiological movements + variations in size, shape and position of CTV in relation to internal reference point

ITV = CTV + IM (Internal Margin)

Question 9

organs at risk can be

Answer 9

serial , parrallel or serial-parallel

Question 10

serial OAR

Answer 10

spinal cord
dose above the tolerance limit even to a small volume can impair the function

Question 11

parrallel OAR

Answer 11

lungs
the main parameter for impairing the function is the proportion of the lungs which recieves the dose above the tolerance level

Question 12

serial-parallel OAR

Answer 12

heart
serial structure= coronary arteries
parrallel structure =myocardium

Question 13

ICRU 62 emphasises

Answer 13

OAR movements and changes is shape or size , aswell as uncertainties must be considered