One method embodiment of the present invention is a process for using deterministic methods to calculate
dose distributions resulting from radiotherapy treatments, diagnostic imaging, or industrial sterilization, and for calculating scatter corrections used for image reconstruction. In one embodiment of the present invention, the method provides a means for constructing a deterministic computational grid from an acquired 3-D
image representation, transport of an external
radiation source through
field shaping devices and into the computational grid, calculation of the
radiation scatter and / or delivered
dose in the computational grid, and subsequent transport of the scattered
radiation to detectors external to the computational grid. In another embodiment of the present invention, the method includes a process, by solving the adjoint form of the transport equation, which can enable
patient dose responses to be calculated independently of
treatment parameters and prior to treatment planning, enabling
patient dose fields to be accurately reconstructed during treatment planning and
verification.