Methods and apparatus for the planning and delivery of radiation treatments

A system for planning delivery of radiation dose to a target region within a subject, the system comprising a processor, the processor configured to:

• initialize a first plurality of control points located on a trajectory, the trajectory comprising relative movement between a treatment radiation source and the subject, wherein initializing the first plurality of control points comprises assigning, to each the first plurality of control points, one or more axis positions which specify a position of the treatment radiation source relative to the subject;
• specify a second plurality of control points along the trajectory, the second plurality of control points comprising a larger number of control points than the first plurality of control points;
• and
• iteratively optimize a simulated dose distribution relative to a set of one or more optimization goals over the second plurality of control points to thereby determine a radiation delivery plan by assigning each of the second plurality of control points optimized values for one or more radiation delivery parameters.