DOSIMETRIC SCINTILLATING SCREEN DETECTOR FOR CHARGED PARTICLE RADIOTHERAPY QUALITY ASSURANCE

摘要

An apparatus and method are provided for performing Quality Assurance of complex beams of penetrating radiation inside a patient. A detector with a transverse scintillating screen images the radiation inside a tissue phantom with high spatial resolution. The scintillator is comprised of a mixture of two or more scintillators emitting different spectra of light and having different characteristic responses as a function of the beam LET value. The optics relaying the scintillation output have variable transmission with wavelength, further shaping the spectrum of light transmitted to the imaging sensor which also has spectrally varying sensitivity. Parameters of the scintillator construction, the optics, and the imaging sensor are chosen so the output of the composite detector is proportional to a characteristic of the input beam, for example the dose deposited as a function of depth inside the tissue phantom.

主权项

1. An apparatus for determining the spatial distribution and intensity of penetrating radiation beams characterized generally by a propagation direction inside a body, the apparatus comprising:
a tissue phantom disposed between the radiation source and a radiation detector; a scintillating screen disposed behind the tissue phantom for emitting light in response to the radiation comprising a mixture of at least two scintillators wherein each scintillator has a different characteristic response and a different spectral output; a means of optical communication of the scintillator output to at least one imaging sensor wherein the means of optical communication has a nonuniform spectral transmission; and at least one imaging sensor in optical communication with the scintillating screen for providing a high resolution imaging sensor output indicative of the spatial distribution and intensity of the radiation beam wherein the imaging sensor has a nonuniform spectral sensitivity; wherein the composition of the scintillator, the means of optical communication, and imaging sensors are selected so as to comprise a system wherein the imaging sensor output is proportional to a characteristic of the radiation beam incident on the scintillator at each measurement position accessible with the tissue phantom.