Radiotherapy planning systems

A method of producing a treatment plan for a radiotherapy apparatus, the method comprising:

• generating an input data set including:
• a dose distribution for a target volume to be irradiated, wherein the dose distribution is configured to be delivered by the radiotherapy apparatus,
• a three-dimensional volume image characterizing tissue types within the target volume, and
• a set of apparatus parameters which characterize the radiotherapy apparatus;
• generating a treatment plan for delivery of the dose distribution by:
• optimizing a function representing a time-dependent response of the tissue types within the target volume to the dose distribution,
• deriving a four-dimensional dose distribution for the target volume based on the optimized function, wherein for each tissue type within the target volume, the four-dimensional dose distribution characterizes a tissue-specific timing pattern for radiation dose delivery to the tissue type, and
• generating the treatment plan based on the four-dimensional dose distribution and the set of apparatus parameters;
• and
• controlling the radiotherapy apparatus to irradiate the target volume based on the generated treatment plan.

A treatment planning apparatus, comprising:

• a data storage element configured to store an input data set, the input data set including:
• a dose distribution for a target volume to be irradiated, wherein the dose distribution is configured to be delivered by a radiotherapy apparatus,
• a three-dimensional volume image characterizing tissue types within the target volume, and
• a set of apparatus parameters which characterize the radiotherapy apparatus;
• and
• a computational processor programmed to apply a set of instructions to the input data set, the computational processor being programmed to execute the set of instructions to:
• optimize a function representing a time-dependent response of the tissue types within the target volume to the dose distribution,
• derive a four-dimensional dose distribution for the target volume based on the optimized function, wherein for each tissue type within the target volume, the four-dimensional dose distribution characterizes a tissue-specific timing pattern for radiation dose delivery to the tissue type,
• generate a treatment plan for the radiotherapy apparatus based on the four-dimensional dose distribution and the set of apparatus parameters, and
• control the radiotherapy apparatus to irradiate the target volume based on the generated treatment plan.