Performance Evaluation of a Multichannel All-In-One Phantom Dosimeter for Dose Measurement of Diagnostic X-ray Beam

Abstract

We developed a multichannel all-in-one phantom dosimeter system composed of nine sensing probes, a chest phantom, an image intensifier, and a complementary metal-oxide semiconductor (CMOS) image sensor to measure the dose distribution of an X-ray beam used in radiation diagnosis. Nine sensing probes of the phantom dosimeter were fabricated identically by connecting a plastic scintillating fiber (PSF) to a plastic optical fiber (POF). To measure the planar dose distribution on a chest phantom according to exposure parameters used in clinical practice, we divided the top of the chest phantom into nine equal parts virtually and then installed the nine sensing probes at each center of the nine equal parts on the top of the chest phantom as measuring points. Each scintillation signal generated in the nine sensing probes was transmitted through the POFs and then intensified by the image intensifier because the scintillation signal normally has a very low light intensity. Real-time scintillation images (RSIs) containing the intensified scintillation signals were taken by the CMOS image sensor with a single lens optical system and displayed through a software program. Under variation of the exposure parameters, we measured RSIs containing dose information using the multichannel all-in-one phantom dosimeter and compared the results with the absorbed doses obtained by using a semiconductor dosimeter (SCD). From the experimental results of this study, the light intensities of nine regions of interest (ROI) in the RSI measured by the phantom dosimeter were similar to the dose distribution obtained using the SCD. In conclusion, we demonstrated that the planar dose distribution including the entrance surface dose (ESD) can be easily measured by using the proposed phantom dosimeter system.

Comparison of X-ray Radiant Power Absolute Measurement between a Free-Air Ionization Chamber and a Cryogenic Electrical Substitution Radiometer

“…Absolute measurement of X-rays’ radiometric quantities with small uncertainties is required in many research fields, e.g., characterization of space instrumentation, X-ray spectrometry, and X-ray diagnostics [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. Light sources of synchrotron radiation (SR) are powerful tools of fundamental and applied sciences due to their high photon flux and tunability, especially in the X-ray region.…”

Feasibility Evaluation of HgI2-based Flexible Dosimeter for Surface Dose Measurements in Radiotherapy

“…In addition, according to Peet and Pryor, MOSFET dosimeters exhibit a 25.0% error in surface dose measurements [7]. Studies on 3D dosimetry have been conducted to obtain 3D dose information in point measurements using a gel-type dosimeter [8] and a multi-channel dosimeter based on fiber optics [9]. These problems have recently led to studies on the bending and flexibility characteristics of dosimeters that can be applied to the human body.…”