Radiation therapy system using a digital tomosynthesis process for near real-time localization

A radiation treatment system comprising:

• a gantry that is rotatably coupled to a drive stand and is configured to rotate about a bore of the radiation treatment system;
• a treatment-delivering X-ray source mounted on the gantry and configured to direct treatment X-rays to a target volume of a patient disposed in the bore;
• an imaging X-ray source mounted on the gantry;
• an X-ray imager mounted on the gantry;
• and
• a processor configured to:
• while causing the gantry to rotate in a first direction from a first treatment delivery position to a second treatment delivery position, cause the imaging X-ray source to direct X-rays through the target volume and toward the X-ray imager, receive a set of X-ray projection images from the X-ray imager in response to the X-rays being directed toward the X-ray imager, and cause a treatment-delivering X-ray source to direct a treatment beam to the target volume;
• based on the set of X-ray projection images, generate image data for a digital volume that includes the target volume;
• after generating the image data for the digital volume, determining a current location of the target volume based on the image data for the digital volume;
• and
• based on the set of X-ray projection images, monitor the patient for a loss of breath hold.

A computer-implemented method of radiation therapy, the method comprising:

• while causing a gantry of a radiation therapy system to rotate continuously in a first direction through a first treatment arc from a first treatment delivery position to a second treatment delivery position, causing an imaging X-ray source mounted on the gantry to direct X-rays through a target volume of a patient and receiving a set of X-ray projection images from an X-ray imager mounted on the gantry, wherein the set of X-ray projection images are generated via a digital tomosynthesis process;
• determining a current location of the target volume based on the set of X-ray projection images;
• while causing the gantry to continue to rotate to the second treatment delivery position:
• initiating delivery of a treatment beam of a treatment-delivering X-ray source mounted on the gantry to the target volume;
• and
• continuing to cause the gantry to rotate in the first direction from the second treatment delivery position to a third treatment delivery position;
• and
• based on the set of X-ray projection images, monitor the patient for a loss of breath hold.