Fig. 7
From: Characteristics of non-coplanar IMRT in the presence of target-embedded organs at risk
HT D mean and MU. The mean dose to the healthy tissue HT D mean (top) and the necessary monitor units MU (bottom) for topologies A, B, C vs. number of beams (# beams). (A) spherical OAR; (B) cylindrical OAR; (C) banana-shaped OAR. The plans were optimized using pure fluence optimization (Fluence) and DMPO for maximum 120 segments (120 S) and 64 segments (64 S), respectively. Compared are the results from four techniques: (a) quasi-isotropic non-coplanar (Q4π), (b) beams arranged in two orthogonal planes (2P), (c) coplanar (Co; reference), (d) coplanar + 1 orthogonal beam (Co + 1)