Sun Nuclear Corporation

William E Simon

Jakub Kozelka

Jeffrey M Kapatoes

Benjamin E Nelms

Jie Shi

Thomas Allen Simon

Jeffrey L Hildreth

Mark Rose

Myron Brookshire

Kai Wundke

Andreas A Schönfeld

Erik Alquist

Ronald J Watts

Seth Brechbill

Thomas L Powers

William Austhof

Thomas Allan Simon

Craig A Iannello

Glenn W Ernsberger

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.

High dose rate radiation therapy systems and dosimetry

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.

Systems and methods to account for tilt of a radiation measurement system

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.

Beam angle direction determination

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.

Radiation therapy dose calculation

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.

Dosimetry for radiotherapy treatment verification

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.

Systems and methods for composite dose quality assurance with three dimensional arrays

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.

Multiple axes scanning system and method for measuring radiation from a radiation source

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.

Three dimensional dosimetry using solid array geometry

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.

Radiation therapy plan dose perturbation system and method

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.

Wide field calibration of a multi-sensor array

A low-cost radon detector using a solid state diode having a depletion layer disposed close enough to a test medium that alpha particles deposit their energy in the depletion layer. The signal produced by the diode is amplified and pulses are discriminated for levels over a threshold typical of pulse levels produced by radioactive decay of radon daughters on the surface of the sensor. More than one amplifier and threshold detector are provided, and the sensor can have plural solid state diodes. Pulses occurring exclusively on one channel are counted and pulses occurring in coincidence on more than one channel are ignored as instances of transient disturbance. A conductive enclosure around the sensor element can be biased to force radon daughter ions to plate out the sensor, whereupon decay of the daughters produces pulses falling closely into pulse height ranges well above the noise threshold. Pulse counts and time lapse are monitored both long term and short term.

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Melbourne, FL, United States of America

William E Simon