| abstract |
Systems and methods for tracking a target volume, e.g., tumor, in real-time during radiation treatment are provided. Under one aspect, a system includes an ultrasound probe, an x-ray imager, a processor, and a computer-readable medium that stores a 3D image of the tumor in a first reference frame and instructions for causing the processor to: instruct the x-ray imager and ultrasound probe to substantially simultaneously obtain inherently registered x-ray and set-up ultrasound images of the tumor in a second reference frame; establish a transformation between the first and second reference frames by registering the 3D image and the x-ray image; instruct the ultrasound probe to obtain an intrafraction ultrasound image of the tumor; registering the intrafraction ultrasound image with the set-up ultrasound image; and track target volume motion based on the registered intrafraction ultrasound image. |