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 assess the clinical benefits of intravenous dexmedetomidine infusion administered before radiotherapy in patients with lung cancer, focusing on hemodynamic stability, stress response modulation, and pulmonary protection. </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">A total of 120 lung cancer patients scheduled for thoracic radiotherapy (6 MV linear accelerator, Varian Clinac iX, USA; 2 Gy/fraction, 30 fractions, total dose 60 Gy) between April 2022 and January 2024 were divided into the control group (n = 60) and dexmedetomidine group (n = 60). Prior to each radiotherapy session, the control group received intravenous 0.6 </span></span></span><span lang="el" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:el">&mu;</span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">g/kg normal saline, while the study group received 0.6 </span></span></span><span lang="el" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:el">&mu;</span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">g/kg dexmedetomidine. Hemodynamic parameters, oxidative stress markers, and stress hormone levels were recorded at baseline (T0), midway (T1), end of session (T2), and 24 hours post-radiotherapy (T3). Pulmonary complications, cognitive impairment, and adverse reactions were documented. </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 dexmedetomidine group maintained significantly more stable mean arterial pressure, heart rate, arterial oxygen partial pressure (PaO₂), and oxidative stress profiles (P < 0.05). Compared to controls, they showed lower arterial carbon dioxide partial pressure (PaCO₂), malondialdehyde, cortisol, and adrenocorticotropic hormone (ACTH) levels. Pulmonary injury occurred in 5.0% vs. 16.7% (P = 0.041), and cognitive impairment in 6.7% vs. 20.0% (P = 0.031). Adverse reaction rates were similar between groups (P > 0.05). </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">Pre-radiotherapy dexmedetomidine stabilizes hemodynamics, attenuates oxidative and neuroendocrine stress responses, and reduces pulmonary and cognitive complications without increasing adverse events, suggesting a valuable role in peri-radiotherapy management of lung cancer patients.</span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Tahoma"><span style="font-style:italic"><span style="language:en-US"></span></span></span></span></span></span></span></span></span></span><br> <span style="font-size:10pt"><span style="line-height:119%"><span style="font-family:Calibri"><span style="color:black">&nbsp;</span></span></span></span></div> Dexmedetomidine, lung neoplasms, radiotherapy, hemodynamics, oxidative stress, cognitive dysfunction. 953 958 http://ijrr.com/browse.php?a_code=A-10-1-1420&slc_lang=en&sid=1 J. Zheng 7900319475328460032526 7900319475328460032526 No Department of Anesthesiology, The Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226000, China J. Zhu 7900319475328460032527 7900319475328460032527 No Department of Anesthesiology, Haimen District Peoples Hospital, Nantong, Jiangsu 226000, China J. Sun sunjiafengntyy@163.com 7900319475328460032525 7900319475328460032525 Yes Department of Anesthesiology, The Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226000, China