Tumor tracking during radiation treatment using ultrasound imaging

A system for tracking an anatomy of interest, the system comprising:

• a memory to store:
• a first pre-acquired 3D image of the anatomy of interest of a patient in a first reference frame;
• a second pre-acquired 3D image, of a second modality, of the anatomy of interest of the patient in the first reference frame;
• and
• a registration of the first pre-acquired 3D image with the second pre-acquired 3D image;
• and
• a processor, operative coupled with the memory, to:
• receive, from an ultrasound probe, a set-up ultrasound image of the anatomy of interest of the patient in a second reference frame;
• establish a transformation between the first and second reference frames by registering the set-up ultrasound image with the second pre-acquired 3D image;
• receive, from the ultrasound probe, an intrafraction ultrasound image of the anatomy of interest of the patient;
• register the intrafraction ultrasound image with the set-up ultrasound image;
• and
• track motion of the anatomy of interest based on the registered intrafraction ultrasound image.