A Clinical Study On Predicting Acute Radiation Pneumonitis Using Both Physical And Biologic Parameters

Purpose: To study the relationship between the level of plasma transform growth factor-β₁(TGF-β₁),interlenkin-6(IL-6),thrombomodulin (TM),dose-volume factors and acute radiation pneumonitis (ARP) in patients receiving thoracic irradiation, And to evaluate the value of predicting ARP using these parameters.Patents: 44 patients were allotted into this study. 41 patients were male and 3 female, with a median age of 57 years (39-80). 27 patients had lung cancer, 15 esophageal carcinoma, and 1 thymoma. 20 patients had adjuvant radiotherapy after surgery. 19 patients received concurrent radiochemotherapy. The median value of given doses (Gy), V₂₀, V₃₀ and MLD (GY) were 61 (50-70), 19% (8-29 %) , 11% (4-22 %) and 9.6 (5-15), respectively.Methods: Levels of serum TGF-β₁,IL-6,TM were measured with enzyme-linked immunosorbent assay (ELISA) before radiotherapy (Baseline, B-), while lung function was examined. At 30Gy, Levels of three cytokines were measured again(Midist, M-). ARP was graded according to NCI common toxicity criteria (CTCAE v3.0 ) before irradiation and every week after biganing irradiation, the follow time was three months. All patients were treated with computed tomography based 3-dimensional planning, and dose-volumetric parameters analyzed were percentage of the lung volume that received a dose (Gy) or more〔5 (V₅), 10 (V₁₀), 20 (V₂₀), 30 (V₃₀), 40(V₄₀)〕; mean lung dose (MLD); and total dose. After statistic analyzing, obtained relative conclusions.Results: 15(34.1%) patients had ARP. 9 got grade 2 ARP and 6 had grade 3. Hemoglobin (＜12g/dl vs≥12g/dl), sex, forced expiratory volume in 1 second (＜2L vs≥2L ), history of thoracic surgery and concurrent radio-chemotherapy had no significantly difference between patients who got severe ARP and those who did not. In univariate analyses, MLD, age (＜60 vs≥60), Smoking history, value of M-TGF-β₁ and increased M-TM level were associated with severe ARP (P＜0.05). M-TGF-β₁ value was 396.06±338.17 and 865.76±270.30 pg/ml in non-ARP and ARP group (P=0.000). 1 out of 13 patients (7.69 %) who had increased M- TM value suffered of ARP, while 14 out of 31 patients (45.16 %) whose M- TM value lower than B-TM suffered of ARP(P=0.044). In multivariate analysis, MLD and the value of M- TGF-β₁ were associated with severe ARP.Conclusion: TGF-β₁ and MLD are significant indicators of ARP. The changes of TM level during thoracic irradiation has a predictive value for radiation pneumonitis.