Abstract: Disclosed is a system for quality assurance of high dose rate radiation therapy. The system includes a radiation delivery system configured to deliver high dose rate radiation therapy, with the radiation delivery system including a radiation source and a collimating system. The system also includes a radiation detection system having a diode to measure high dose rate radiation from the radiation source, an operational amplifier to transform the output of the diode to a measurable voltage, and a voltage source configured to apply a reverse bias to a component of the radiation detection system.

Abstract: Systems, methods, and computer program products that are configured to account for tilt of a radiation measurement system are disclosed. In one embodiment, a system includes a scanning system with a radiation detector, the scanning system configured to enable movement of the radiation detector. The system also includes a non-transitory machine-readable medium storing instructions which, when executed by at least one programmable processor, cause the at least one programmable processor to perform various operations including moving the radiation detector through a first, second, and third vertical calibration path and recording a first, second, and third radiation detector response within 3 cm of a water surface, and controlling the scanning system to move the radiation detector through at least one measurement path that takes into account a scanning system tilt, the at least one measurement path determined based on at least the first, second, and third radiation detector responses.

Abstract: Systems, methods, and computer program products that are configured to account for tilt of a radiation measurement system are disclosed. In one embodiment, a system includes a scanning system with a radiation detector, the scanning system configured to enable movement of the radiation detector. The system also includes a non-transitory machine-readable medium storing instructions which, when executed by at least one programmable processor, cause the at least one programmable processor to perform various operations including moving the radiation detector through a first, second, and third vertical calibration path and recording a first, second, and third radiation detector response within 3 cm of a water surface, and controlling the scanning system to move the radiation detector through at least one measurement path that takes into account a scanning system tilt, the at least one measurement path determined based on at least the first, second, and third radiation detector responses.

Abstract: A system is disclosed that includes a radiation therapy device with a gantry. The radiation therapy device is configured to deliver a radiation beam at an angle determined by orientation of the gantry. Also, a pair of radiation detectors are located at a fixed position to receive radiation originating from the radiation beam. Each of the radiation detectors in the pair generate differing responses to the radiation beam at the angle. The system further includes computer hardware configured to perform operations that determine the angle of the gantry utilizing the differing responses from the pair of radiation detectors.

Abstract: Radiation therapy dose calculation methods, systems and computer program products, for use with a treatment delivery device for treating a patient and utilizing a scattered radiation detector in making independent dose calculations. The scattered radiation detector is configured to acquire measurement information during patient treatment, which is used to determine an estimate of the output of the treatment delivery device. Other information is acquired including patient imaging data, gantry angle information and collimator position information utilized during patient treatment. The acquired information is utilized along with the treatment delivery device output estimate to determine dose delivered to the patient.

Abstract: A system is disclosed that includes a radiation therapy device with a gantry. The radiation therapy device is configured to deliver a radiation beam at an angle determined by orientation of the gantry. Also, a pair of radiation detectors are located at a fixed position to receive radiation originating from the radiation beam. Each of the radiation detectors in the pair generate differing responses to the radiation beam at the angle. The system further includes computer hardware configured to perform operations that determine the angle of the gantry utilizing the differing responses from the pair of radiation detectors.

Abstract: Data from a first radiation detector and a second radiation detector can be used to determine a radiation dose pattern delivered to a radiation target from a radiation source. The first radiation detector can be positioned to intercept ionizing radiation directed from the radiation source toward the radiation target before the ionizing radiation has impinged on the radiation target and the second radiation detector can be positioned to intercept the ionizing radiation after the ionizing radiation has passed through the radiation target. Methods, systems, articles of manufacture, and computer program products are described.

Abstract: Radiation therapy dose calculation methods, systems and computer program products, for use with a treatment delivery device for treating a patient and utilizing a scattered radiation detector in making independent dose calculations. The scattered radiation detector is configured to acquire measurement information during patient treatment, which is used to determine an estimate of the output of the treatment delivery device. Other information is acquired including patient imaging data, gantry angle information and collimator position information utilized during patient treatment. The acquired information is utilized along with the treatment delivery device output estimate to determine dose delivered to the patient.

Abstract: A method for performing composite dose quality assurance with a three-dimensional (3D) radiation detector array includes delivering a radiation fraction to the 3D array according to a radiation treatment (RT) plan, measuring absolute dose per detector of the 3D array, per unit of time, determining a radiation source emission angle per unit of time, synchronizing the RT plan with the measured absolute doses and determined radiation source emission angles to determine an absolute time for a control point of each beam of the synchronized RT plan, converting the beams of the synchronized RT plan into a series of sub-beams, generating a 3D relative dose grid for each of the sub-beams, applying a calibration factor grid to each of the 3D relative dose grids to determine a 3D absolute dose grid for each of the sub-beams, summing the 3D absolute dose grids to generate a 3D absolute dose deposited in the 3D array, and determining a 3D dose correction grid for application to the RT plan based on the 3D absolute dose.

Abstract: A method has been developed to reconstruct angle of the radiation field using a 3D measurement device. The 3D measurement device is positioned in the radiation beam. The novel method uses measured values and information about attenuation in the 3D detector and calculates direction of the primary beam.

Abstract: Data from a first radiation detector and a second radiation detector can be used to determine a radiation dose pattern delivered to a radiation target from a radiation source. The first radiation detector can be positioned to intercept ionizing radiation directed from the radiation source toward the radiation target before the ionizing radiation has impinged on the radiation target and the second radiation detector can be positioned to intercept the ionizing radiation after the ionizing radiation has passed through the radiation target. Methods, systems, articles of manufacture, and computer program products are described.

Abstract: A method for performing composite dose quality assurance with a three-dimensional (3D) radiation detector array includes delivering a radiation fraction to the 3D array according to a radiation treatment (RT) plan, measuring absolute dose per detector of the 3D array, per unit of time, determining a radiation source emission angle per unit of time, synchronizing the RT plan with the measured absolute doses and determined radiation source emission angles to determine an absolute time for a control point of each beam of the synchronized RT plan, converting the beams of the synchronized RT plan into a series of sub-beams, generating a 3D relative dose grid for each of the sub-beams, applying a calibration factor grid to each of the 3D relative dose grids to determine a 3D absolute dose grid for each of the sub-beams, summing the 3D absolute dose grids to generate a 3D absolute dose deposited in the 3D array, and determining a 3D dose correction grid for application to the RT plan based on the 3D absolute dose.

Abstract: A treatment safety device is operable by a computer-based treatment safety module to prevent, by at least one of an operational interlock and a warning indicator, a medical treatment unless the treatment safety module determines that predetermined treatment verification criteria are met. The treatment safety device can tie into an existing operational interlock, such as an electrical door interlock. In a radiation oncology application, the treatment safety module verification criteria can include a satisfactory correspondence between elements of a pending treatment and an intended treatment.

Abstract: A three dimensional radiation measurement scanning system includes a circular drive operable with horizontal and vertical drives for moving a radiation detector through first, second and third orthogonal axes in a three dimensional scanning of the detector in a water tank. Motor are coupled to the drives and activated by a controller for providing the movement of the radiation detector which providing radiation field sensing signals for locations of the detector throughout the tank. A reference detector is fixed for comparing its radiation field measurements with those of the scanned radiation detector. An offset mount carries the radiation detector allowing it to be extended beyond the circular ring gear during horizontal movement of the radiation detector and thus position the radiation detector at wall surfaces of the water tank.

Abstract: A dosimeter comprising an ionizing radiation detector array is used to generally encompass a three dimensional geometric shape such as that employed as a phantom in radiation dosimetry measurements. The ionizing radiation detector array may include passive or active detectors. The active detectors in the array may comprise diodes, ionization chambers, luminescent sensors or amorphous silicon. The three dimensional geometric shape may comprise a shape defined by a closed directrix, wherein each of a plurality of detectors within the ionizing detector array is within an envelope defined by a generatrix of the directrix. The closed directrix may be an open or closed cylinder, or a structure having a cross section described by a polygon. The plurality of detectors may only be positioned on or at least proximate the envelope.

Abstract: A method of determining a patient dose during or prior to therapy from an external radiation beam includes determining a dose distribution from a patient plan as delivered in a QA phantom at each appropriate beam angle and comparing the dose distribution determined from measurements or calculations to a corresponding treatment planning system (TPS) dose modeled distribution in the QA phantom and providing a correction distribution when applied to the TPS dose modeled distribution results in the dose distribution determined. The correction distribution may optionally be interpolated to non-measured points for each beam angle and geometrically projected toward the source of radiation through a volume that equals a dose volume of the TPS for a patient beam for each beam angle. The correction distribution is applied to the TPS patient dose volume for each beam angle for providing a corrected dose distribution in the patient.

Abstract: A three dimensional radiation measurement scanning system includes a circular drive operable with horizontal and vertical drives for moving a radiation detector through first, second and third orthogonal axes in a three dimensional scanning of the detector in a water tank. Motor are coupled to the drives and activated by a controller for providing the movement of the radiation detector which providing radiation field sensing signals for locations of the detector throughout the tank. A reference detector is fixed for comparing its radiation field measurements with those of the scanned radiation detector. An offset mount carries the radiation detector allowing it to be extended beyond the circular ring gear during horizontal movement of the radiation detector and thus position the radiation detector at wall surfaces of the water tank.

Abstract: A method of determining a patient dose during or prior to therapy from an external radiation beam includes determining a dose distribution from a patient plan as delivered in a QA phantom at each appropriate beam angle and comparing the dose distribution determined from measurements or calculations to a corresponding treatment planning system (TPS) dose modeled distribution in the QA phantom and providing a correction distribution when applied to the TPS dose modeled distribution results in the dose distribution determined. The correction distribution may optionally be interpolated to non-measured points for each beam angle and geometrically projected toward the source of radiation through a volume that equals a dose volume of the TPS for a patient beam for each beam angle. The correction distribution is applied to the TPS patient dose volume for each beam angle for providing a corrected dose distribution in the patient.

Abstract: A dosimeter comprising an ionizing radiation detector array is used to generally encompass a three dimensional geometric shape such as that employed as a phantom in radiation dosimetry measurements. The ionizing radiation detector array may include passive or active detectors. The active detectors in the array may comprise diodes, ionization chambers, luminescent sensors or amorphous silicon. The three dimensional geometric shape may comprise a shape defined by a closed directrix, wherein each of a plurality of detectors within the ionizing detector array is within an envelope defined by a generatrix of the directrix. The closed directrix may be an open or closed cylinder, or a structure having a cross section described by a polygon. The plurality of detectors may only be positioned on or at least proximate the envelope.

Abstract: A method has been developed to calibrate the relative radiation response of sensors in an array by substitutional analysis of the sensor outputs caused by a radiation field wider than the array. The array is positioned in the wide field in such a way that the sensor positions in the array are exchanged once by translation in order to calculate ratios of neighboring detector sensitivity and once by rotation in order to calculate ratios of mirror detector sensitivities. There is no dependence on dose reproducibility, field flatness or symmetry. The method requires that the profile shape produced by the machine during each measurement be reproducible and that the array movements do not affect the scattering conditions.