Treatment-speed regulated tumor-tracking

A method for delivering therapeutic radiation during a radiation treatment procedure to a tumor moving within a patient due to physiological activity of said patient, comprising:

• in a preliminary procedure, monitoring motion of said tumor in location and shape over a time period corresponding to said radiation treatment procedure, generating a surrogate signal representing said motion of said tumor, and recording said signal in a recording device to provide an estimated surrogate signal;
• determining a radiation therapy plan for the patient, wherein the radiation therapy plan defines a planned sequence of varying parameters of a radiation beam to track the tumor motion and a planned rate of execution of said sequence of parameters;
• configuring a radiation therapy device to deliver radiation in accordance with the radiation therapy plan;
• positioning the patient within said radiation therapy device;
• activating the radiation therapy device to perform said planned sequence of parameters of said radiation beam;
• monitoring tumor motion during said radiation therapy procedure to provide a treatment surrogate signal;
• determining the difference between said estimated surrogate signal and said treatment surrogate signal;
• and
• regulating the speed of said radiation treatment procedure by varying the rate of execution of said sequence of radiation beam parameters in accordance with said difference between said estimated surrogate signal and said treatment surrogate signal.