Objective: To observe the preventive effect of Yangyin Yifei decoction for assistance of radiotherapy in treating patients with acute radiation-induced pneumonia (RIP)

and to investigate its influence on serous interleukin-1 (IL-1)

interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Method: One hundred and twenty-five patients were randomly divided into the control group (90 cases) and the observation group (93 cases). Patients in both groups received radiosurgery

and patients in the control group received symptomatic therapy without any traditional Chinese medicine treatment. Patients in the observation group received 1 dose Yangyin Yifei decoction. All patients in both two groups received 3 months of treatment. Incidence rate of RIP

injury degree and the occurrence time were recorded. Before and after the treatment

degree of dyspnea was evaluated by Watters method of point rating

and quality of life was evaluated by Karnofsky performance status score (KPS). Vital capacity (VC)

forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were detected. Levels of IL-1

IL-6 and TNF-α were also detected. Result: Incidence rate of RIP in the observation group was 41.11%

which was higher than that of 19.35% in the control group (P<0.05). Duration of RIP in the observation group was shorter than that in the control group (P<0.01). Radiation dose in the observation group was less than that in the control group (P<0.01). After treatment

patients' radioactive injury degree and Watters scores in the observation group were both lower than those in the control group (P<0.01). Levels of VC

FVC and FEV1 were higher than those in the control group (P<0.05). KPS score was higher than that in the control group (P<0.01). Levels of IL-1

IL-6 and TNF-α were lower than those in the control group (P<0.01). Conclusion: Assistance of Yangyin Yifei decoction could reduce the incidence rate of RIP and the injury degree caused by RIP

ameliorate dyspnea and stabilize patients' lung function

and its mechanism of action may be related to relieving inflammatory response.