Predictive values of TNF-α, IL-6, IL-10 for radiation pneumonitis

Background: To investigate the expression of TNF-alpha, IL-6, IL-10 in the plasma of patients with lung cancer who received radiation therapy (RT), and to analyze the correlation between these cytokines and radiation pneumonitis (RP). Materials and Methods: Patients with lung cancer who received 3D CRT in our hospital were prospectively evaluated. Circulating cytokine levels were measured with ELISA before RT and at the end of RT. Regular follow-up was undertaken 3 months after RT. Statistical analysis was applied to determine the relevance of cytokines to radiation-induced lung injury. Results: Of 104 patients, 29 (27.9%) developed RP. The levels of TNF-alpha and IL -6 levels in the plasma after RT were significantly higher than before RT (p<0.05), whereas IL-10 levels were significantly lower after RT than before RT (p<0.05). Before RT, TNF-alpha levels were higher in RP group (p<0.05),but there were no differences in TNF-alpha levels after RT. No association was observed between IL-6 and IL-10 levels and the risk of RP. Univariate analysis showed that baseline pulmonary function, smoking history, histopathology, lung volume receiving 20 Gy (V20), Mean lung dose (MLD) and total radiation dose were related to RP, but only MLD was an independent risk factor for RP in lung cancer patients (OR>1). Conclusion: TNF-alpha levels in plasma were closely related to RP but still cannot be used as predictors for RP.