IMRT 2018

Summary

• We are not treating a simple geometrical object, but we are working with very simplistic geometric target volumes • Planning Target Volume, PTV, is a purely geometrical concept • In simple cases, with small movement the IGRT strategy will counter the effects on the IMRT dose distribution • In other cases, the PTV concept might not suffice in maintaining target coverage • Not taking motion into account could lead to serious under- and over- dosage, i.e. interplay effects between breathing and beam modulation • Motion management can be used to measure extent of motion, mitigate tumour motion, or introduce space between organs by increasing motion • Several motion management methods account for breathing-induced motion during imaging, planning and treatment delivery, such as gating.