Fig. 7: The dose distributions delivered with proton arc and a SpeleoFilter can achieve similar plan qualities compared to intensity modulated proton therapy (IMPT).
From: Range-compensated pencil beam scanning proton Arc therapy: a feasibility study

Monte Carlo simulated dose profiles are shown for a two-field IMPT (A), a proton arc delivery using a SpeleoFilter (B), the dose-volume histogram (DVH) (C), and the difference profile between these two delivery techniques (D). The legend provided for the DVH lists the dose coverage plots for the pencil beam scanning target volume (PBSTV, red), body (blue), and surrounding 10 mm rind of nearby healthy tissue (green).