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">The purpose of our study was to investigate the doses received by critical organs, namely the bladder, rectum, and sigmoid colon, in the treatment plans using single-channel (SC) or multi-channel (MC) applicators in high dose rate (HDR) brachytherapy treatments for vaginal cancer patients. </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">We established treatment plans for 10 patients received 45Gy (1.8Gy&times;25fractions) external radiotherapy and then subsequently treated with HDR brachytherapy using MC applicators in the Oncentra Brachytherapy Treatment Planning System (OBTPS). These plans, originally created with MC applicator in the OBTPS, were redefined to simulate an SC applicator, where only the central channel active was kept active. To compare the doses to critical organs, new plans were generated with a prescribed dose of 5Gy to the clinical target volume (CTV). During optimization, it was ensured that 90% of the CTV received the prescribed dose (5Gy), in accordance with Groupe Europ&eacute;en de Curieth&eacute;rapie and the European SocieTy for Radiotherapy and Oncology (GEC-ESTRO) criteria. The doses received by critical organs were analyzed for volumes of 0.1, 1, and 2cc in both SC and MC applicator plans. </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">A significant difference was found in rectal doses at 1cc and 2cc (p=0.022 and p=0.022, respectively); bladder doses at 0.1cc 1cc and 2cc (p=0.013 for all); and sigmoid colon dose at 1cc (p=0.012). </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">HDR brachytherapy plans using MC applicators delivered lower doses to critical organs compared to SC applicators. Thus, MC applicators are preferable for better organ sparing in vaginal cancer treatment.</span></span></span></span></span></span></span></span></span></div> Brachytherapy, rectum, sigmoid colon, urinary bladder, applicators. 1023 1027 http://ijrr.com/browse.php?a_code=A-10-1-1430&slc_lang=en&sid=1 L. Suncak lxleyla@hotmail.com 7900319475328460032490 7900319475328460032490 Yes The Institute of Health Sciences at Istanbul University, Istanbul, Turkey C.K. Akbas 7900319475328460032491 7900319475328460032491 No Division of Medical Physics, Istanbul University Oncology Institute, Istanbul, Turkey G.U. Alveroglu 7900319475328460032492 7900319475328460032492 No Division of Medical Physics, Istanbul University Oncology Institute, Istanbul, Turkey S. Özkurt 7900319475328460032493 7900319475328460032493 No Division of Radiation Oncology, Istanbul University Oncology Institute, Istanbul, Turkey K.A. İbiş 7900319475328460032494 7900319475328460032494 No Division of Radiation Oncology, Istanbul University Oncology Institute, Istanbul, Turkey S. Küçücük 7900319475328460032495 7900319475328460032495 No Division of Radiation Oncology, Istanbul University Oncology Institute, Istanbul, Turkey H.B. Becerir 7900319475328460032496 7900319475328460032496 No Division of Medical Physics, Istanbul University Oncology Institute, Istanbul, Turkey