en Radiation Biology Radiation Biology تحقيق بديع Original Research <div style="text-align: justify;"><span style="font-size:10pt"><span style="text-justify:inter-word"><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">In this study, intensity-modulated radiation therapy&nbsp;plans were made with and without couch rotation in patients with right unilateral breast cancer, and a dosimetry analysis was carried out to compare the radiation doses received by target and normal tissues. </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="color:#1f497d"><span style="language:en-US">:</span></span></span></span> <span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">The radiotherapy planning tomography sets of 10 patients who underwent right unilateral mastectomies were retrospectively selected. Target volumes and normal at-risk organs were recontoured, two radiotherapy plans were created for each patient, and these plans were compared by dosimetry analyses. </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="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">Doses in the target volume </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:black"><span style="language:en-US">(D2%, D98, D50, HI, VRI, and T-PTV-V95) were similar between the plans. In terms of </span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">organs at-risk </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:black"><span style="language:en-US">doses, the maximum doses in the contralateral breast were similar between the plans, while the differences in all other </span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">organs at-risk</span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:black"><span style="language:en-US"> dose parameters between the plans were statistically significant. All dosimetry parameters of the heart were significantly lower in the plans with couch rotation.</span></span></span></span> <span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:black"><span style="language:en-US">Ipsilateral lung doses were higher in the plans with couch rotation</span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:black"><span style="language:en-US">. Contralateral lung and mean breast doses were significantly lower in the plans with couch rotation. </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-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="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">In this study, organs at-risk doses were reduced, especially for the heart and the contralateral breast, in patients who were subjected to postmastectomy radiotherapy with right thoracic wall and regional nodal irradiation without compromising radiotherapy dose coverage for the target volumes by rotating the treatment couch by 270&deg;.</span></span></span></span></span></span></span></span></div> Right unilateral breast cancer, postmastectomy radiotherapy, IMRT with couch rotation, OAR, cardiac toxicity. 203 210 http://ijrr.com/browse.php?a_code=A-10-1-1029&slc_lang=en&sid=1 S.Y. Rakici sema.rakici@erdogan.edu.tr 7900319475328460023466 7900319475328460023466 Yes Department of Radiation Oncology, Recep Tayyip Erdogan University Faculty of Medicine, Rize, Turkey M. Eren 7900319475328460023467 7900319475328460023467 No Department of Radiation Oncology, Recep Tayyip Erdogan University Faculty of Medicine, Rize, Turkey