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 is to identify the standard minimum segment width [MSW] in terms of planning outcomes of Volumetric modulated arc therapy [VMAT] in patients with Head and Neck Carcinoma [HNC]. </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">A retrospective analysis was conducted using planning computed tomography scans from 15 patients diagnosed with head and neck carcinoma. Four separate VMAT plans, utilizing MSW of 0.5 cm, 1.0 cm, 1.5 cm, and 2.0 cm, were created in the Monaco Treatment Planning system [TPS]version 5.11.03. Target volume and critical structures were optimized with the same criteria. The comparison focused on Conformity Index [CI], Homogeneity Index [HI], target volume coverage, dose to Organs at risk [OARs], and total Monitor units (MUs). Data analysis was performed using Jamovi software. At p<0.05, statistical significance was established. </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">MSW of 1.0 cm plans showed significantly enhanced planning target volume [PTV] coverage [p=0.021], fewer monitor units [p=0.03], and an optimal combination of Conformity [CI = 0.816&plusmn;0.214] and Homogeneity [HI = 1.065&plusmn;0.017]. Furthermore, the spinal cord received a substantially lower maximum dose in plans created with 0.5 cm and 1.0 cm MSWs compared to those with wider segment widths [p=0.017]. </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">Among the configurations tested, the 1.0 cm MSW offered the most favorable balance between precise target coverage, organ-at-risk sparing, and overall treatment delivery efficiency for head and neck cancer using VMAT planning.</span></span></span></span></span></span></span></span></span></div> Head and Neck Neoplasms, Radiotherapy Planning, VMAT, Organ Sparing, Segment Width. 1151 1155 http://ijrr.com/browse.php?a_code=A-10-1-1627&slc_lang=en&sid=1 L. Malar 7900319475328460035078 7900319475328460035078 No Medical Radiation Physics program, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, India J. Nagesh jjyothi.nagesh@manipal.edu 7900319475328460035079 7900319475328460035079 Yes Department of Radiation Oncology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India S.S. Nair 7900319475328460035080 7900319475328460035080 No Department of Radiation Oncology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India C. Shambhavi 7900319475328460035081 7900319475328460035081 No Medical Radiation Physics program, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, India S. Lewis 7900319475328460035082 7900319475328460035082 No Department of Radiation Oncology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India A. Singh 7900319475328460035083 7900319475328460035083 No Department of Radiation Oncology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India K. Sharan 7900319475328460035084 7900319475328460035084 No Department of Radiotherapy Justice KS Hegde Medical College, Deralakatte, Nitte Karnataka, India Y.M. Harshini 7900319475328460035085 7900319475328460035085 No Medical Radiation Physics program, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, India