Figure 2. Target definition, dose distributions and dose-volume histograms for stereotactic radiosurgery.

The images show axial views (A-C); coronal views (D-F); target definition (A, D); representative isodose distributions (B, C, E, F); representative isodose surfaces: absolute doses (upper) and the corresponding biological effective doses with an alpha/beta ratio of 10 (BED₁₀) (G); dose-volume histograms (DVHs) (H).

(A, D) A gross tumor volume (GTV) and an isotropic 2-mm margin-added object (GTV + 2 mm) for evaluation. (B, E) GTV and 64% (48.3 Gy) isodose surface (IDS) relative to the maximum dose. (C, F) The concentrically laminated steep dose gradients inside and outside the GTV boundary generated with volumetric-modulated arcs.