Accurately simulating the production of radiotherapy portal images using non-zero beam angles

作者：Kairn T^*; Warne D; Kenny J; Dwyer M

来源：Radiation Measurements, 2011, 46(12): 1967-1970.

DOI：10.1016/j.radmeas.2011.05.074

• Computer simulation
• EPID
• Medical imaging
• Radiation therapy

In this study, the delivery and portal imaging of one square-field and one conformal radiotherapy treatment was simulated using the Monte Carlo codes BEAMnrc and DOSXYZnrc. The treatment fields were delivered to a humanoid phantom from different angles by a 6 MV photon beam linear accelerator, with an amorphous-silicon electronic portal imaging device (a-Si EPID) used to provide images of the phantom generated by each field. The virtual phantom preparation code CTCombine was used to combine a computed-tomography-derived model of the irradiated phantom with a simple, rectilinear model of the a-Si EPID, at each beam angle used in the treatment. Comparison of the resulting experimental and simulated a-Si EPID images showed good agreement, within gamma(3%, 3 mm), indicating that this method may be useful in providing accurate Monte Carlo predictions of clinical a-Si EPID images, for use in the verification of complex radiotherapy treatments.

• 出版日期2011-12