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="color:#1f497d"><span style="font-weight:bold"><span style="language:en-US">:</span></span></span></span></span> <span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">It is essential to evaluate the accuracy of dose calculation for treatment planning systems (TPSs). This study&#39;s primary goal was to evaluate the accuracy of dose calculation for ISOgray TPS in the presence of a wedges in the treatment fields. </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">Materials 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">GATE (Geant4 Application for Tomography Emission) as a Monte Carlo (MC) code was utilized to model the 6 MV photon beam of an Elekta Compact linac. It did MC code verification for three different field sizes and three depths for open, and wedged fields with gamma index tool. Following the confirmation, the percentage depth dose (PDD) and dose profile were calculated using the TPS and compared with the simulation results. In the next step, the TPS dose calculations for the 10&times;10cm2 field with different wedge angles were compared by the result from analytical formula. </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">The PDD and dose profiles for open fields met the gamma index criteria. However, there was disagreement for large wedged fields. The dose profiles of wedge angles using Petti analytical equation were compared to ISOgray dose profiles. Results showed that dose profile points with all wedge angles meet the gamma index criteria except for the 45</span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Cambria"><span style="language:en-US">˚</span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US"> wedge angle. </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">Conclusions: </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 results indicated that the disagreement between MC and TPS dose calculations increases by increasing wedge angle and field size. The uncertainty is due to TPS dose calculation algorithm causing noticeable disagreement. A MC-based TPS for dose calculation is recommended to reduce the error in dose calculation or at least medical physicist consider this issue.</span></span></span></span></span></span></span></span></span></div> IMRT, Effective wedge angle, motorized wedge, radiotherapy planning, ISOgray, Monte Carlo method. 303 308 http://ijrr.com/browse.php?a_code=A-10-1-1174&slc_lang=en&sid=1 S. Raghavi 7900319475328460026874 7900319475328460026874 No Medical Physics Department, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran H.R. Sadoughi 7900319475328460026875 7900319475328460026875 No Medical Physics and Radiology Department, Faculty of Paramedicine, North Khorasan University of Medical Sciences, Bojnurd, Iran M.E. Ravari 7900319475328460026876 7900319475328460026876 No Medical Physics Department, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran M.A. Tajik Mansoury 7900319475328460026877 7900319475328460026877 No Medical Physics Department, Shahid Beheshti University of Medical and Science, Tehran, Iran M. Behmadi behmadim881.mph@gmail.com 7900319475328460026878 7900319475328460026878 No Cancer Research Center, Semnan University of Medical Sciences, Semnan, Iran