Physics Bucharest 2017

IMRT: What are the Potential Weak Links?

 MU-dose relationship is not intuitive  Simple point dose verification calculations do not cover the properties of the whole dose distribution  Inverse Treatment Planning  The multiple constraints, (competing) objectives, and the numerous degrees of freedom make plan optimization a large scale multi- criteria, non-convex, combinatorial, and discrete problem and thereby not straightforward to solve.  Mechanical accuracy of the linear accelerator  Gantry, collimator, table iso-center (typically < 1 mm)

Ezzell G, Galvin JM, Low D, Palta JR, Rosen I, Sharpe MB, Xia P, Xiao Y, Xing L and Yu CX. Guidance document on delivery, treatment planning, and clinical implementation of IMRT: Report of the IMRT subcommittee of the AAPM Radiation Therapy Committee. Med. Phys. 30: 2090 – 2115, 2003