Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 50 1 2012 01 15 43 46 EN Hooshang Amir Rasouli Department of Radiotherapy-Oncology, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Maryam Mirzaie Moghadam Department of Radiotherapy-Oncology, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Morteza Tabatabaiefar Department of Radiotherapy-Oncology, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Farnaz Taslimi Department of Radiotherapy-Oncology, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Khosro Mojir Sheybani Department of Radiotherapy-Oncology, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Asadollah Alidoosti Department of Radiotherapy-Oncology, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Ahmad Ameri Department of Radiotherapy-Oncology, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Pedram Fadavi Department of Radiotherapy-Oncology, 7 Tir Hospital, Tehran University of Medical Sciences and Health Services, Tehran, Iran. Shahrzad Aref Department of Radiotherapy-Oncology, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 2015 09 28 The objective of this study was to determine and compare Cystatin C changes before and after radiotherapy in patients with stomach cancer who were candidate for radiotherapy. This study was conducted as a prospective cohort one. Eighteen patients with definite diagnosis of stomach cancer under treatment by radiotherapy who presented to Radiotherapy-Oncology Center of Imam Hossein Hospital, Tehran-Iran, and the treatment in all cases was simultaneous chemoradiation with Xeloda were included. In all patients before radiotherapy and after radiotherapy serum creatinine (Cr) and Cystatin C were measured simultaneously. Mean cystatin level before treatment (1.2±0.4) was significantly lower than that of post-treatment (1.6±0.36), (P=0.001). Serum Cr level before treatment was 1.15±0.33 and after radiotherapy was 1.08±0.24 and did not show significant difference. Glomerular filtration rate (GFR) of the patients before radiotherapy was -46.8 ± 21.0 and after radiotherapy was 43.8±15.8 that did not have significant difference (P=0.146) and also blood urea nitrogen (BUN) before radiotherapy was 20.72±3.7 and 20 ± 6.38 after radiotherapy that did not have significant difference (P=0.6). Comparison of the Cystatin C difference with total radiation dose of the kidneys that are put in three dose groups in radiotherapy field had association that in dose of less that 18 gray (Gy) the Cystatin C change showed significant and positive association (P=0.027; r=0.52) and about 18-24 Gy the Cystatin C difference showed significant and negative association (P=0.023, r=-0.53). It seems that for evaluating the renal function, serum Cystatin C measurement is preferable than serum Cr. level. https://acta.tums.ac.ir/index.php/acta/article/view/3857 https://acta.tums.ac.ir/index.php/acta/article/download/3857/3832