en Physiology پژوهشي Research <p data-end="573" data-start="0"></p> <div style="text-align: justify;"><span style="font-size:12px;"><span style="font-family:Times New Roman;"><b>Background:</b> Radiotherapy (RT) plays a crucial role in the treatment of patients with head and neck cancers (HNC). However, RT is associated with toxicity to tissues and organs. Given the high global incidence of head and neck tumors, understanding whether head and neck radiotherapy disrupts blood pressure (BP) regulation is of significant clinical importance. Therefore, this study investigated the effects of head and neck RT on BP and orthostatic hypotension in patients with head and neck tumors.<br> The objective of this study was to evaluate the effects of head and neck radiotherapy on BP changes and the incidence of orthostatic hypotension in patients with HNC.<br> <b>Methods:</b> To achieve this, 25 patients from the Shafa Radiotherapy Center of 5 Azar Hospital in Gorgan in 2024 participated in the study (15 males and 10 females). The mean age of the patients was 55.2 &plusmn; 10.3 years. The highest incidence was associated with oral cavity cancer (13 cases). BP was measured in supine, sitting, and standing positions at baseline (before the onset of RT), one month, and three months after the start of RT. To estimate orthostatic BP, the patient&rsquo;s BP was recorded after 5 minutes in the supine position, and subsequently at 5-minute intervals in sitting and then standing positions. Patients underwent between 20 and 35 sessions of RT.<br> <b>Results:</b> The results of this study showed that hypertension was the most typical consequence, and both systolic and diastolic BP decreased. Orthostatic hypotension occurred in 48% of patients, which may be related to the small sample size. A notable relationship was detected between baseline hypertension and reductions in both systolic and diastolic BP. Additionally, an increased cumulative RT dose was associated with greater BP reduction.<br> <b>Conclusion</b>: This study demonstrates that BP alterations may represent an important consequence of RT in patients with HNC. Higher cumulative doses of RT were associated with significant reductions in systolic BP and an increased risk of orthostatic hypotension. These findings may have important implications for clinical management and medication selection to reduce RT-related cardiovascular side effects.</span></span></div> Blood Pressure, Radiotherapy, Head and Neck Cancer, Hypotension, Orthostatic 23 26 http://jcbr.goums.ac.ir/browse.php?a_code=A-10-671-2&slc_lang=en&sid=1 Bahar Moslemi baharmoslemi@gmail.com 10031947532846006635 10031947532846006635 No Student Research Committee, Golestan University of Medical Sciences, Gorgan, Iran Hamid Sepehri hamsep49@yahoo.com 10031947532846006636 10031947532846006636 No Neuroscience Research Center, Golestan University of Medical Sciences, Gorgan, Iran; Biomedical Research Institute, School of Medicine, Golestan University of Medical Sciences, Gorgan, Iran Alireza Khoshbin Khoshnazar علیرضا خوشبین khoshbin@goums.ac.ir 10031947532846006637 10031947532846006637 Yes Department of Biochemistry and Medical Physics, Faculty of Medicine, Golestan University of Medical Sciences, Gorgan, Iran