en Radiation Biology Radiation Biology تحقيق بديع Original Research <div style="text-align: justify;"><span style="font-size:10pt"><span style="text-justify:newspaper"><span style="text-kashida-space:50%"><span style="line-height:119%"><span style="font-family:Calibri"><span style="color:black"><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Background:</span></span></span></span></span></span> <span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">To generate the Monte Carlo (MC) 3D dose distribution in both in-field and out-of-field regions for three-dimensional conformal radiotherapy (3DCRT) of breast cancer patients and to compare it with the dose calculations from two available commercial treatment planning systems (TPS). </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Material and Methods: </span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">The Prowess Panther TPS was initially used to create the treatment plan and underwent a simulation process using the MCNPX 2.6.0 Monte Carlo code. Dose maps, profiles, dose volume histograms (DVHs), and mean doses for organs at risk (OARs) were calculated. To evaluate the accuracy of dose calculations, global gamma index analysis was conducted to ensure conformity between MC dose calculations and the two TPSs. </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Results: </span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">For individual beams, comparing Prowess to MC shows that the gamma passing rates (GPR) range from 94.3% to 99.2%, with a GPR of 91.2% for all beams combined. In contrast, when comparing RayStation to MC, the GPRs range from 96.0% to 99.0%, with a total beam GPR of 94.3%. Regarding out-of-field doses, the two TPSs can provide reliable dose calculations only for organs receiving mean doses greater than 500-700 cGy.&nbsp;</span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Conclusion: </span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">The MC model was benchmarked for 3DCRT plans, demonstrating that it could provide accurate MC doses in the in-field area. Furthermore, the comparison between MC and TPS doses shows that RayStation performs better in the in-field region. Nonetheless, both TPS-based out-of-field estimates were unreliable, indicating the importance of utilizing MC methods to estimate out-of-field doses.</span></span></span></span></span></span></span></span></span></div> Monte Carlo, breast cancer, radiotherapy. 763 770 http://ijrr.com/browse.php?a_code=A-10-1-1575&slc_lang=en&sid=1 N. Rafat-Motavalli 7900319475328460034376 7900319475328460034376 No Department of Physics, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran H. Miri-Hakimabad mirihakim@um.ac.ir 7900319475328460034377 7900319475328460034377 Yes Department of Physics, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran E. Hoseinian-Azghadi 7900319475328460034378 7900319475328460034378 No Department of Physics, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran L. Rafat-Motavalli 7900319475328460034379 7900319475328460034379 No Department of Physics, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran M. Dayyani 7900319475328460034380 7900319475328460034380 No Research and Education Department, Reza Radiotherapy and Oncology Center, Mashhad, Iran T. Tuğrul 7900319475328460034381 7900319475328460034381 No Department of Radiation Oncology, Medicine Faculty of Van Yüzüncü Yıl University, Van, Turkey