Figures & data
Figure 1. The dimensions of the two surrogates: Two-marker RPM box (TMB) to the left and novel respiratory surrogate (NRS) to the right. The NRS has a base with a diameter of 38 mm and reflective markers affixed on a stalk with 30 mm spacing between them, i.e., the same distance as on the TMB. The stalk of the surrogate was 60 mm with the reflective markers elevated 21 mm above the base.
Figure 2. Surface dose measured directly under the two-marker RPM box (TMB) and the novel respiratory surrogate (NRS) when exposed to 500 MU in a 10 × 10 cm2 field of 6 MV photons. Graph (A) shows the profiles below the centerline of the TMB (red), NRS (blue), and without any surrogates (magenta). The 2D profiles inserted below the graph show the surface dose directly below the TMB (B) and NRS (C). The surrogates were positioned with the reflective markers facing right in the image.
