Background and aims: One of the main potential problems of radiotherapy (RT) in breast cancer is the increase in treatment-related inflammation. This study aimed to investigate the effect of eight weeks of moderate-intensity aerobic training (AT) on serum levels of tumor necrosis factor α(TNF-α) and interleukin-6 (IL-6) in rats undergoing RT. Materials and Methods:In this experimental study, 32 male rats were randomly divided into four groups of eight members including (1) healthy control (C), (2) AT, (3) RT, and (4) AT + RT groups. Rats were first anesthetized with ketamine-xylazine solution (K, 60-90 kg/mg; Z, 6-10 kg/mg) and then located on a Plexiglas plate with a thickness of 1 cm. Photon beam RT was performed using X-rays with a dose of 11 Gy from an Elekta compact linear accelerator (Elekta Compact 6-MV China). AT program was performed for eight weeks, five days a week, and one session a day for 60 minutes (70-75% of VO2max). Afterwards, one-way ANOVA was run to examine the research variables. Results:According to the results, TNF-αwas significantly higher in the RT group compared to the C group (P = 0.003), whereas IL-6 levels were significantly lower in the AT + RT group compared to the RT group (P = 0.001) and the C group (P = 0.027). Further, the levels of this cytokine were significantly lower in the AT group compared to the RT group (P = 0.006) and similarly in the RT group compared to the C group (P = 0.03). Conclusion:RT led to an increase in pro-inflammatory cytokines; however, performing AT could only significantly reduce the IL-6 levels.
