Real-time patient motion monitoring using a magnetic resonance linear accelerator (MR-LINAC)

A method for real-time tracking of a target, during a radiotherapy treatment using a magnetic resonance linear accelerator (MR-Linac), the method comprising:

• generating a dictionary of simulated expanded potential patient measurements and corresponding simulated potential patient states using a preliminary motion model and based on an initial actual measurement and a corresponding initial actual patient state;
• training, using a machine learning technique, a correspondence motion model relating an input patient measurement to an output patient state using the dictionary;
• receiving a real-time stream of images from an image acquisition device;
• estimating, using the processor, patient states corresponding to images in the real-time stream of images using the correspondence motion model;
• tracking a radiation therapy target of a patient in real-time using the patient states;
• and
• outputting tracking information for the radiation therapy target for display on a display device.