A Correlation Study Of Plasma Tnf-α, Il-6, Ace Levels And Dose-volume Parameters To Radiation Pneumonitis

Objective:To evaluate the value of plasma tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),angiotensin-converting enzyme(ACE) levels and dose-volume parameters in predicting radiation pneumonitis (RP) by studying the correlation between the level of plasma TNF-a,IL-6,ACE,DVH and RP. Materials and methods:123 thoracic neoplasm patients were treated with three dimensional conformal radiation therapy or intensity modulated radiation therapy. The enzyme-linked immunosorbent assay (ELISA)was applied to detect the plasma TNF-a, IL-6 and ACE levels of patients before radiotherapy (pre-RT) and at the time of 45～50Gy irradiation(post-RT).Radiation pneumonitis was classified according to the RTOG morbidity scoring classification.Grade 2 or more RP was taken as the main end point.The relationship between the levels of plasma TNF-a,IL-6, ACE, V10, V20,V30,MLD and the incidence rate of radiation penumonitis were analyzed. Mean lung dose (MLD) and the Vx were considered as the dose-volume parameters (Vx was the percentage of the lung volume that irradiated x Gy or more to the whole lung volume).Analysis was performed by SPSS 16.0 software. Results:Among 123 patients,18 of them had RP.16 of them got grade 2 RP and 2 got grade 3 RP.The levels of plasma TNF-a, IL-6 and ACE pre-RT and post-RT were statistically difference (P=0.000,0.000,0.000).Between RP and non-RP group,there were no significant difference in the plasma TNF-a, IL-6 and ACE levels pre and post-RT.The differences of V10,V20,V30,MLD in non-RP and RP group were significant (P=0.011,0029,0.009,0.006).The RP incidence rates bewteen V10<50% group and V10≥50% group,V20<25% group and V20>25% group,V30<12% group and V30≥12% group,MLD<14Gy group and MLD≥14Gy group were all significant different (P=0.005,0.002,0.028,0.000).The RP incidence rates were 3.33%(1/30) in non-chemotherapy group and 18.28%(17/93)in chemotherapy group (P=0.044). Multivariate analysis showed that there was no independent factor for the RP incidence in the plasma TNF-a,IL-6,ACE levels, V10,V20, V30,MLD and chemotherapy history. Conclusions:The differences in plasma TNF-a,IL-6,ACE levels between pre-RT and post-RT group was significant, which has non correlation with the RP incidence. The RP incidence was associated with V10,V20,V30,MLD and groups with chemotherapy history.There was no independent factor in which we metioned above for the RP incidence.