Automated calibration for radiation dosimetry using fixed or moving beams and detectors

A method of calibrating a radiotherapy system, the method comprising:

• providing a detection medium that is adapted to respond to exposure to ionizing radiation;
• preparing a calibration dose response pattern by irradiating predefined regions of the detection medium with different ionizing radiation dose levels;
• measuring responses of the detection medium in the predefined regions to obtain a calibration that relates the response of the detection medium to ionizing radiation dose level;
• wherein the different dose levels are at least in part obtained by exposing the detection medium to a beam of ionizing radiation while differentially shielding the predefined regions of the detection medium;
• and
• wherein differentially shielding the predefined regions of the detection medium comprises attenuating the beam of ionizing radiation with a multi-leaf collimator.

A method of calibrating a radiotherapy system, the method comprising:

• providing a detection medium that is adapted to respond to exposure to ionizing radiation;
• preparing a calibration dose response pattern by irradiating predefined regions of the detection medium with different ionizing radiation dose levels;
• measuring responses of the detection medium in the predefined regions to obtain a calibration that relates the response of the detection medium to ionizing radiation dose level;
• wherein the different dose levels are at least in part obtained by exposing the detection medium to a beam of ionizing radiation while differentially shielding the predefined regions of the detection medium;
• and
• wherein differentially shielding the predefined regions of the detection medium comprises attenuating the beam of ionizing radiation with a secondary collimator.

A method of calibrating a radiotherapy system, the method comprising:

• providing a detection medium that is adapted to respond to exposure to ionizing radiation;
• preparing a calibration dose response pattern by irradiating predefined regions of the detection medium with different ionizing radiation dose levels;
• measuring responses of the detection medium in the predefined regions to obtain a calibration that relates the response of the detection medium to ionizing radiation dose level;
• wherein the different dose levels are at least in part obtained by exposing the detection medium to a beam of ionizing radiation while differentially shielding the predefined regions of the detection medium;
• and
• wherein differentially shielding the predefined regions of the detection medium comprises attenuating the beam of ionizing radiation with a fixed block, the fixed block having ionizing radiation attenuation characteristics that vary across a surface of the fixed block exposed to ionizing radiation.

A method of calibrating a radiotherapy system the method comprising:

• providing a detection medium that is adapted to respond to exposure to ionizing radiation;
• preparing a calibration dose response pattern by irradiating predefined regions of the detection medium with different ionizing radiation dose levels;
• measuring responses of the detection medium in the redefined regions to obtain a calibration that relates the response of the detection medium to ionizing radiation dose level;
• wherein the different dose levels are at least in part obtained by shaping a beam of ionizing radiation;
• and
• wherein shaping the beam of ionizing radiation comprises blocking a portion of the beam using a multi-leaf collimator.

A method of calibrating a radiotherapy system the method comprising:

• providing a detection medium that is adapted to respond to exposure to ionizing radiation;
• preparing a calibration dose response pattern by irradiating predefined regions of the detection medium with different ionizing radiation dose levels;
• measuring responses of the detection medium in the predefined regions to obtain a calibration that relates the response of the detection medium to ionizing radiation dose level;
• wherein the different dose levels are at least in part obtained by shaping a beam of ionizing radiation;
• and
• wherein shaping the beam of ionizing radiation comprises blocking a portion of the beam using a secondary collimator.

An apparatus for calibrating a radiotherapy system, comprising:

• an amorphous silicon detector array as a detection medium that is adapted to respond to exposure to ionizing radiation;
• a calibration dose response pattern prepared by irradiating predefined regions of the detection medium with different ionizing radiation dose levels;
• and
• responses of the detection medium measured in the predefined regions to obtain a calibration that relates the response of the detection medium to ionizing radiation dose level.