Article Figures & Data
Figures
- Figure 1.
Schematic overview with IEC 61217 Y-Z view of the Elekta Synegy linear accelerator head with Agility MLC.
- Figure 2.
Schematic drawing of the leaf tilt design. Leaf sides are focused on a virtual source which is shifted from the radiation source perpendicular to the leafs' travel direction to reduce inter-leaf leakage.
- Figure 3.
Comparison of the MC calculations with ionization chamber measurements for 5, 10, 20 and 40 cm2 square open fields for 6 MV. (a): depth dose profiles, lateral dose profiles at 10 cm depth along (b) the X-axis (parallel to MLC travel direction) and (c) the Y-axis (perpendicular to MLC travel direction). The profiles were normalized to the central dose of a 10×10 cm2 field at 10 cm depth. The lines correspond to the measurements and the squares to the MC calculations.
- Figure 4.
Ray tracing of the central 4 leaves modeled in BEAMnrc. The particles were traced and their positions recorded when they crossed the leaf boundaries. The leaves in Y-Z view were visualized by plotting their outline.
- Figure 5.
Comparison of relative film measurements with MC calculations at 1.5 cm depth in a closed leaf field with a 6 mm gap remaining (upper curves). MC calculation of a fully closed leaf field (lower curve) is also included for comparison. All profiles were normalized to the central axis point dose in a 10×10 cm2 open field at the same depth.
- Figure 6.
Comparison of the MC calculated dose profiles with diode measurements at SSD of 90 cm and at 10 cm depth for an irregular field. Both profiles were normalized to the central point dose of a 10×10 cm2 open square field at the same depth. The blue lines correspond to the measurements and the red squares to the MC calculations.
- Figure 7.
Comparison of MC calculations and measurements of (a) the dose profiles at isocenter (position indicated by the dashed line in the insert) and (b) the gamma index plots for a step-and-shoot 7-field head-and-neck IMRT treatment plan. The line corresponds to the film measurement and the red squares to the MC calculations. In the gamma index plots, the deviations above gamma index=1 (3%/3 mm) are shown in color.
- Figure 8.
Comparison of MC calculations and measurements of (a) the dose profiles at isocenter (position indicated by the dashed line in the insert) and (b) the gamma index plots for a two-arc head-and-neck VMAT treatment plan. The line corresponds to the film measurement and the red squares to the MC calculations. In the gamma index plots, the deviations above gamma index=1 (3%/3 mm) are shown in color.
