ABSTRACT
Normal lung tissues are inevitably exposed to X-ray in thoracic radiotherapy,causing radiation-induced lung injury (RILI).The main pathological manifestations include the accumulation of inflammatory cells,release of cytokines,accumulation and proliferation of fibroblasts,and excessive deposition of alveolar interstitial collagen in the irradiated region.RILI severely affects the treatment compliance and quality of life and even threatens the life in the patients receiving radiotherapy.In recent years,numerous studies have found that Th1/Th2 imbalance is closely associated with the development and progression of RILI,and the cytokine network plays an executive role in the progression of RILI.Therefore,restoring the Th1/Th2 balance in vivo may provide a new way to prevent and treat RILI.
ABSTRACT
Objective To establish the rabbit model of radiation-induced lung injury (RILI) for the study of CT perfusion. Methods Forty-eight New Zealand rabbits were randomly divided into two groups, 36 rabbits in test group were administered with 25 Gy of single fractionated irradiation in the whole unilateral lung, and the other 12 rabbits in control group were sham-irradiated. All rabbits were sacrificed at 1, 6, 12, 24, 48, 72 h, and 1,2, 4, 8, 16, 24 week after irradiation respectively, then six specimens were extracted from upper, middle and lower fields of bilateral lungs, respectively. The pathological changes were observed with light and electron microscopies. The expression of TNF-α and TGF-β1 in local lung tissue was detected by immunohistochemistry. Results In test group, RILI occurred at early stage,characterized by acute inflammatory reaction, and featured by the progressing fibrosis at later stage. The expression of TNF-α and TGF-β1 1 and 72 h post-irradiation were statistically different between test and control groups (t = 3.04-14. 95,P ＜ 0. 05 ). Thickness of alveolar wall, density of pulmonary interstitium 12 h of post-irradiation, amount of fibroblast and fibrocyte from interstitium 24 h post-irradiation were statistically different between two groups ( t = 4.44-39. 78, P＜ 0.05 ), and correlated with the time postirradiation (r = 0. 821, 0. 872, 0. 682). There was statistical differences among the relative amount of collagen fibers at time points post-irradiation in test group ( F = 100.31, P ＜0.05), while no difference in control group ( F= 1.00, P ＜ 0.05 ). The relative amount of collagen fibers was statistically different between two groups 72 h post-irradiation (t = 3.07-45.18, P＜0.05 ), and correlated with the time postirradiation (r = 0.993 ). Conclusions Stable and reliable rabbit model of RILI could be established through single fractionated irradiation in whole unilateral lung with 25 Gy of high-energy X-rays, which may simulate the occurrence and development of evolution of RILI.
ABSTRACT
Objective To observe the radioprotective effect of low dose mitomycin C(MMC) on chest carcinoma. Methods 100 cases of chest carcinomas confirmed by histologic or cytologic diagnosis, including, esophageal carcinoma 54 cases, lung cancer 46 cases, were randomized into study group and control group, 50 cases in each group. The study group was treated with low dose MMC (0.002 mg/kg iv one time per week, about 5 ~ 7 times in the course) during routine radiotherapy, the control group was treated with routine radiotherapy only. Results All of 100 cases completed the treatment. Acute radiation- induced esophagitis of study group and control group was 30 % and 48 % respectively (?2=3.897,P =0.048). Acute radiation- induced pneumonia of study group and control group was 4 % and 16 % respectively (?2 =4.001,P =0.045). Hematologic toxicity of study group and control group was 50 % and 48 % respectively (?2=0.208, P =0.648). Response rate of study group (84 %) was obviously higher than that of control group (68 %) (?2 =4.089, P =0.043). Conclusions Low dose MMC combining with chest carcinoma's radiotherapy can obviously reduce acute radiation- induced esophagitis and pneumonia, without obvious hematologic toxicity, meanwhile increase radiation effect.
ABSTRACT
Objective To prospectively study the relation between transforming growth factor beta-1 (TGF-?_1), V_(20) and lung function (PFTs) and radiation pneumonia (RP), as well as to set up a prediction model of RP. Methods From Jan 2004 to Dec 2005, 121 valid patients with esophageal carcinoma or lung cancer were treated with conventional thorax radiotherapy(RT) by 15 MV X-ray beams to a total D_T 60-68 Gy over 30-34 fractions in 42-46 days. All patients received chest CT scanning before RT. Dose volume his- togram(DVH) and V_(20) were obtained through 3-dimensional TPS. Serum TGF-?_1 and PFTs of the patients were measured both before and after RT as well as on the 20th day after the beginning of RT. RP was diag- nosed basing on contrasted CT and clinical symptoms. Results RP was diagnosed in 32 of all 121 pa- tients. The results of Logistic Regression Statistic showed that V_(20) and TGF-?_1 ratio (after RT/before RT) significantly influenced the incidence of RP. Patients with V_(20)≥30% had more RP than patients with V_(20)