PyRate: an open-source tool to calculate dose rates for spot scanning proton beams

Calculates instantaneous and average dose rates for spot scanning proton beams, given machine and dosimetric parameters as input.

Required measurements

• Energy-dependent beam spot size and transmission
• Reference dose rate

Input parameters

• Target shape : Rectangular or circular.
• Target size (mm) : The size of the target area to cover with a homogeneous dose. Horizontal and vertical size (mm) if target is rectangular, radius (mm) if target is circular.
• Target dose (Gy) : The desired dose over the target area.
• Spot spacing (mm) : The spacing between the spot centres.
• Overscan fraction (sigma) : Option to scan the beam over a greater area than the target size: total field size = target area + overscan.
• Scan pattern : The order in which the spots in the spot map are irradiated. Can use pre-defined patterns such as a raster scan, or define a custom scan pattern by defining the order of spots to irradiate.