Physics Bucharest 2017
6/3/2017
IMRT – Why? The biological argument, dose escalation
Probability of Tumor Control
1.0
Probability of Normal Tissue Damage
Therapeutic Effect (B)
“Increased conformity keeps high dose levels away from OAR”
Therapeutic Effect (A)
Respons
MAX. TOXICITY LEVEL
0
A B
Target Dose (Gy)
3
ESTRO physics course 2017
IMRT – Why? Looking at conformity
“Conformity index” is a measure of how well confined to the target volume: CI= V target / V treated Conventional RT gives a low CI whereas the CI of IMRT approached unity.
Conventional Radiotherapy
Intensity Modulated Radiotherapy
Knoos T, Kristensen I, Nilsson P: Volumetric and dosimetric evaluation of radiation treatment plans: radiation conformity index. Int J Radiat Oncol Biol Phys 1998, 42(5):1169-1176
4
Made with FlippingBook