BACKGROUND: Quite a number of in vitro experiments indicate that low dose He-Ne laser can stimulate the cell growth and blood vessel regeneration therefore to improve the damages caused by ischemia. However, it needs further study on the in vivo experiments.OBJECTIVE: To study the protective effects of intravascular low dose laser irradiation to ischemic reperfusion of rats and explore its mechanism.DESIGN: A randomised and controlled trial based on experinental animals.SETTING: Department of Neurology of a hospital of a university.MATERIALS: The experiment was completed in the Surgery Experimental Animal Center of West China Hospital of Sichuan University. Healthy male SD rats of class Ⅱ which aged between 5 to 6 months with weight of 372 to 418 grams[mean weight(388.48 ± 10. 57) g] were provided by Animal Research Center of Sichuan University.INTERVENTIONS: Middle cerebral artery ischemia model of rats was prepared. Forty SD rats were randomly divided into treatment group and control group with each of 20 rats. Intravascular low dose He-Ne laser irradiation was conducted to rats in treatment group one time every other day, 20 minutes per time and 3 times for a course. Vein puncture was conducted to rats in control group without laser input.MAIN OUTCOME MEASURES: Ratio of infarcted volume RESULTS: The ratio of the cerebral infarction volume in treatment group was (10.43 ± 1.04) and is much lower than that of control group(16.78 ± 1.12).There was statistical difference between two groups( t = 27.14, P ＜ 0.05).CONCLUSION: Intravascular low dose He-Ne laser irradiation has protective effects to cerebral ischemia of rats.

Objective To compare the dosimetric differences in heart and lung among three radiotherapy techniques in the treatment of thoracic esophageal cancer. Methods A total of 15 thoracic esophageal cancer patients treated in Zhejiang Cancer Hospital during the period of January 2015 to February 2016 were enrolled in this retrospective dosimetric study. Three radiotherapy treatment plans, including intensity-modulated radiotherapy ( IMRT) , volumetric intensity modulated arc therapy ( VMAT) with Raystation 4. 0v TPS, and tomotherapy (TOMO) plans with TomoTTM v2. 0. 5 TPS were generated for each patient with a prescribed dose of 60 Gy at 2 Gy per fraction. Dosimetric differences in planning target volume ( PTV) , heart, cardiac subunits and lung were compared. Results The mean volumes of PTV, heart and lung were (399 ±355), (671 ±274) and (3907 ±1717)cm3, respectively. Compared with VMAT and IMRT, TOMO reduced the maximum dose of PTV, heart, left atrium and lung ( H=10. 889, 7. 433, 12. 080, 11. 401, P <0. 05). No difference was observed in conformity or homogeneity among these three plans. Conclusions TOMO reduced the maximum dose to PTV, heart, left atrium and lung compared with VMAT and IMRT, However, no difference in conformity and homogeneity was observed. The impact of dosimetric advantage of TOMO needs further verification due to the interaction between heart and lung for thoracic esophageal cancer patients.