Radiation based treatment beam position calibration and verification

Inventors

Kilby, Warren • Jordan, Petr • Noll, John • Maurer, JR., Calvin

Assignees

Accuray LLC

Abstract

A method of calibration in a radiation delivery system. The method including acquiring, using a camera, an image of a radiation beam incident on a phantom, wherein the radiation beam being emitted by a radiation source of the radiation delivery system and the phantom comprising an X-ray luminescent material. The method further including determining a beam pointing offset based on the image. The method further including calibrating a position of the radiation source of the radiation delivery system based on the beam pointing offset and a relative position of the camera with respect to a beam axis of the radiation beam.

Core Innovation

The described calibration uses a camera to acquire an image of a radiation beam incident on a phantom, where the phantom comprises an X-ray luminescent material. The method determines a position of the camera based on a pattern overlaid on the X-ray luminescent material, and based on the acquired image and the position of the camera, calibrates a position of the radiation source of the radiation delivery system.

The calibration further includes determining a beam pointing offset based on the image acquired with the camera system. In related configurations, the camera system acquires an image of the radiation beam on the phantom entrance and/or entrance/exit surfaces, and the calibration derives the beam pointing offset and calibrates the radiation source position accordingly.

For verification, the calibration includes acquiring a subsequent image after calibrating the radiation source position and calculating a beam pointing error using the subsequent image and the original image or an earlier image. The disclosed system configurations include cameras coupled to a radiation source head and phantom embodiments that include X-ray luminescent material and a pattern, such as an optical checkerboard pattern, overlaid on the X-ray luminescent material.

Claims Coverage

The document describes independent claim coverage for a calibration method and a calibration system, with two independent claim types centered on camera-based imaging of a radiation beam incident on an X-ray luminescent phantom and calibration of the radiation source position using determined camera position and imaging-based beam alignment features.

Across the independent claim sets, the core inventive coverage lies in using camera imaging of a radiation beam incident on an X-ray luminescent phantom with an overlaid pattern to determine camera position and calibrate the radiation source position based on the image and camera position, with system-level support for determining a beam pointing offset and verifying alignment through calculation of beam pointing error.

Stated Advantages

Documented Applications