Publication Details

Alabd, R., Safavi-Naeini, M., Wilson, K. J., Rosenfeld, A. B. & Franklin, D. R. (2018). A simulation study of BrachyShade, a shadow-based internal source tracking system for HDR prostate brachytherapy. Physics in Medicine and Biology, 63 (20), 205019-1-205019-15.


This paper presents a simulation study of BrachyShade, a proposed internal source-tracking system for real time quality assurance in high dose rate prostate brachytherapy. BrachyShade consists of a set of spherical tungsten occluders located above a pixellated silicon photodetector. The source location is estimated by minimising the mean squared error between a parametric model of the shadow image and acquired images of the shadows projected on the detector plane. A novel algorithm is finally employed to correct the systemic error resulting from Compton scattering in the medium. The worst-case error obtained with BrachyShade for a 13.5 ms image acquisition is less than 1.3 mm in the most distant part of the treatment volume, while for 75% of source locations an error of less than 0.42 mm was achieved.



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