Magnetic resonance guided therapy with interleaved scanning

A non-transitory computer-readable medium carrying machine executable instructions for execution by a processor controlling a medical apparatus, wherein the medical apparatus comprises a radiotherapy apparatus for radiating a target volume;

• a magnetic resonance module for acquiring two types of data namely motion tracking magnetic resonance data and image magnetic resonance data from a subject of which at least a part is located within an imaging volume, wherein the target volume is within the imaging volume;
• wherein execution of the machine executable instructions causes the processor to receive a treatment plan specifying the target volume, the imaging volume and a dose rate of radiation emitted by the radiotherapy apparatus, and in each of a plurality of fractions to repeatedly:
• acquire the motion tracking magnetic resonance data and the image magnetic resonance data by controlling the magnetic resonance module with an interleaved pulse sequence which interleaves motion tracking magnetic resonance data acquisition with image magnetic resonance data acquisition to continuously monitor a motion path of the target volume, the motion tracking magnetic resonance data has a higher temporal resolution than the image magnetic resonance data;
• control the radiotherapy apparatus to radiate the target volume in accordance with the treatment plan;
• calculate a radiation dose distribution map descriptive of a radiation dose received by the subject from the radiotherapy apparatus;
• reconstruct a diagnostic image using the lower temporal resolution image magnetic resonance data;
• control a display to display the diagnostic image and the dose distribution map;
• receive treatment plan update data from a user interface;
• and
• update the treatment plan in accordance with the treatment plan update data.

A method of controlling a medical apparatus, wherein the medical apparatus comprises a radiotherapy apparatus configured to irradiate a target volume;

• a magnetic resonance scanner configured to acquire motion tracking magnetic resonance data and image magnetic resonance data from a subject of which at least a part is located within an imaging volume, wherein the target volume is within the imaging volume, wherein the motion tracking magnetic resonance data has a higher temporal resolution than the image magnetic resonance data, wherein the method comprises receiving a treatment plan specifying the target volume within the imaging volume and a dose rate of radiation emitted by the radiotherapy apparatus, and in each of a plurality of fractions repeatedly:
• controlling the radiotherapy apparatus to radiate the target volume in accordance with the treatment plan;
• acquiring in an interleaved manner the higher temporal resolution motion tracking magnetic resonance data and the image magnetic resonance data by controlling the magnetic resonance scanner with an interleaved magnetic resonance pulse sequence;
• calculating a dose distribution map descriptive of a radiation dose received by the subject from the radiotherapy apparatus;
• reconstructing a diagnostic image using the image magnetic resonance data;
• controlling a display to concurrently display the diagnostic image and the dose distribution map;
• receiving treatment plan update data from a user interface;
• and
• updating the treatment plan in accordance with the treatment plan update data during the radiation of the target volume.