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International Journal of Optics
Volume 2012 (2012), Article ID 724024, 13 pages
Research Article

Megavoltage X-Ray Imaging Based on Cerenkov Effect: A New Application of Optical Fibres to Radiation Therapy

A. Teymurazyan1 and G. Pang1,2,3,4

1Imaging Research, Sunnybrook Health Sciences Centre and Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada M4N 3M5
2Odette Cancer Centre, Toronto, ON, Canada M4N 3M5
3Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada M5G 2M9
4Department of Physics, Ryerson University, Toronto, ON, Canada M5B 2K3

Received 14 July 2011; Revised 19 September 2011; Accepted 20 September 2011

Academic Editor: Baohong Yuan

Copyright © 2012 A. Teymurazyan and G. Pang. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A Monte Carlo simulation was used to study imaging and dosimetric characteristics of a novel design of megavoltage (MV) X-ray detectors for radiotherapy applications. The new design uses Cerenkov effect to convert X-ray energy absorbed in optical fibres into light for MV X-ray imaging. The proposed detector consists of a matrix of optical fibres aligned with the incident X rays and coupled to an active matrix flat-panel imager (AMFPI) for image readout. Properties, such as modulation transfer function, detection quantum efficiency (DQE), and energy response of the detector, were investigated. It has been shown that the proposed detector can have a zero-frequency DQE more than an order of magnitude higher than that of current electronic portal imaging device (EPID) systems and yet a spatial resolution comparable to that of video-based EPIDs. The proposed detector is also less sensitive to scattered X rays from patients than current EPIDs.