The figure summarizes the process of creating photons in the source model and the interdependency of the photon variables.

<p>The figure summarizes the process of creating photons in the source model and the interdependency of the photon variables.</p

Geometric model of an Elekta Synergy linear accelerator and the coordinate system.

<p>Geometric model of an Elekta Synergy linear accelerator and the coordinate system.</p

Comparison of the PSF and VSM-calculated central axis dose planes using gamma analysis.

<p>Comparison of the PSF and VSM-calculated central axis dose planes using gamma analysis.</p

Comparison of the calculated dose with the PSF and VSM algorithms.

<p>(i) Central axis depth dose curves. Lateral profiles at (i) 0 mm (ii) 10 cm and (iii) 20 cm depths for field sizes 3 x 3 cm², 5 x 5 cm², 10 x 10 cm², 20 x 20 cm² and 30 x 30 cm².</p

Particle positions.

<p>(i) Inverse cumulative distribution function for radial positions of particles (continuous line). The knots show the boundaries of the 30 polynomial segements that make up the fitting spline. (ii) Comparison of the radial positions of the PSF particles and those created by the VSM on the phase space. (iii) Distribution of 46.12 million PSF particles on the x-y plane. (iv) Distribution of 46.12 million VSM particles on the x-y plane. (v) Horizontal profile through the centre of the phase spaces.</p

Comparison between the systems of Mannheim and Stanford [1] for a field size of 1 cm.

<p>Comparison between the systems of Mannheim and Stanford [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126246#pone.0126246.ref001" target="_blank">1</a>] for a field size of 1 cm.</p

Proof of principle using an orthotopic implant model.

<p>(a) CT scans used to measure tumor depths and example for a plan using 3 irradiation angles (0°, 270° and 315°). (b) Graphical user interface of the planning application with a standard treatment scheme. (c) Dose distribution of a three-beam plan (details shown in b) in the head phantom measured with a Gafchromic film. (d) Treated tumors show extensive necrotic areas (white arrow) after irradiation, which were not present in untreated tumors. (e) Survival plots of irradiated and untreated mice.</p

Dosimetric characteristics and reproducibility of the system.

<p>(a) Measured data and fitted curves (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126246#pone.0126246.s003" target="_blank">S3 Text</a>, Eq. (1)) of depth-dose rates. Mean values of three measurements in various depths using all established collimators (aperture sizes 1–5 mm) are shown. (b) Radial dose profiles of the five collimators in 1 mm depth. (c) Accuracy assessment of the manipulator in the x-y-plane. A quadratic pattern was produced and the distances between the spots were measured. (d) Assessment of center of rotation accuracy. A pentagon pattern (right side) was used to assess the angle accuracy of the CNC arm.</p

Absorbed dose for different presets in inhomogeneous thorax phantom (column 8), ratio between the imaging methods and reference dose output kV-MV (D/D_ref) (column 9), comparison of MV-contribution dose output between measured and calculated (TPS) absolute dose by percentage difference (column 3–5), and separate contributions of kV- and RBE-corrected MV absorbed dose to kV-MV-CBCT in columns 6+7 (GE: Gray-equivalent with RBE = 2 for kV-dose contribution).

<p>Absorbed dose for different presets in inhomogeneous thorax phantom (column 8), ratio between the imaging methods and reference dose output kV-MV (D/D_ref) (column 9), comparison of MV-contribution dose output between measured and calculated (TPS) absolute dose by percentage difference (column 3–5), and separate contributions of kV- and RBE-corrected MV absorbed dose to kV-MV-CBCT in columns 6+7 (GE: Gray-equivalent with RBE = 2 for kV-dose contribution).</p

FWHM, flatness, symmetry, and penumbra for all collimator aperture sizes at a depth of 1 mm measured using EBT3 films.

<p>FWHM, flatness, symmetry, and penumbra for all collimator aperture sizes at a depth of 1 mm measured using EBT3 films.</p