Methods and systems using magnetic resonance and ultrasound for tracking anatomical targets for radiation therapy guidance

A method for tracking anatomy for radiation therapy treatment, the method comprising:

• acquiring, using an ultrasound device coupled to a patient support, real-time four-dimensional (4D) ultrasound images during a treatment phase for radiation therapy;
• using the acquired real-time 4D ultrasound images to indirectly obtain higher spatial resolution magnetic resonance (MR) images of a tumor using 4D ultrasound images acquired during a pre-treatment phase using the ultrasound device, the higher spatial resolution MR images having a higher spatial resolution than the 4D ultrasound images and wherein the higher spatial resolution MR images acquired during a pre-treatment phase are correlated to the 4D ultrasound images;
• and
• controlling at least one of a radiation therapy or photon beam spatial distribution or intensity modulation generated by a radiation therapy (RT) system using the higher spatial resolution MR images.

A non-transitory computer readable storage medium for tracking anatomy for radiation therapy treatment using a processor, the non-transitory computer readable storage medium including instructions to command the processor to:

• acquire, using an ultrasound device coupled to a patient support, real-time four-dimensional (4D) ultrasound images during a treatment phase for radiation therapy;
• use the acquired real-time 4D ultrasound images to indirectly obtain higher spatial resolution magnetic resonance (MR) images of a tumor using 4D ultrasound images acquired during a pre-treatment phase using the ultrasound device, the higher spatial resolution MR images having a higher spatial resolution than the 4D ultrasound images;
• and
• control at least one of a radiation therapy or photon beam spatial distribution or intensity modulation generated by a radiation therapy (RT) system using the higher spatial resolution MR images.