Design and optimization of large area thin-film CdTe detector for radiation therapy imaging applications.
OBJECTIVE
The authors investigate performance of thin-film cadmium telluride (CdTe) in detecting high-energy (6 MV) x rays. The utilization of this material has become technologically feasible only in recent years due to significant development in large area photovoltaic applications.


METHODS
The CdTe film is combined with a metal plate, facilitating conversion of incoming photons into secondary electrons. The system modeling is based on the Monte Carlo simulations performed to determine the optimized CdTe layer thickness in combination with various converter materials.


RESULTS
The authors establish a range of optimal parameters producing the highest DQE due to energy absorption, as well as signal and noise spatial spreading. The authors also analyze the influence of the patient scatter on image formation for a set of detector configurations. The results of absorbed energy simulation are used in device operation modeling to predict the detector output signal. Finally, the authors verify modeling results experimentally for the lowest considered device thickness.


CONCLUSIONS
The proposed CdTe-based large area thin-film detector has a potential of becoming an efficient low-cost electronic portal imaging device for radiation therapy applications.
Parsai
E Ishmael
EI
Department of Radiation Oncology, University of Toledo Health Sciences Campus, Ohio 43614, USA. e.parsai@utoledo.edu
Shvydka
Diana
D
Kang
Jun
J
D019187:Cadmium Compounds / Q000138:chemical synthesis* / Q000528:radiation effects*; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008567:Membranes, Artificial; D011874:Radiometry / Q000295:instrumentation*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013691:Tellurium / Q000528:radiation effects*
D019187:Cadmium Compounds; D008567:Membranes, Artificial; D013691:Tellurium; C028337:cadmium telluride