The Experimental And Clinical Dosimetric Studies On Radiation Pneumonitis

Background:Matrine is an active ingredient extracted from the traditional Chinese medicine called foxtail-like sophora herb and seed or sophorae radix which contains 98%of oxymatrine.Matrine is a kind of alkaloid which belongs to tetranuclear quinolizidine,and the active component is oxymatrine for it could be deoxidized easily into matrine to produce its effect at the condition of the human intestinal tract where there are bacterium,water,hot and so on.Matrine is mainly used at present to resist hepatic fibrosis,abnormal heart rate,virus and low level of white blood cells caused by radiotherapy or chemotherapy and leucopenia by other reasons.Some experimental studies have demonstrated that matrine can resist hepatic fibrosis by inhibiting liver fibroblasts proliferating and mRNA of typeⅢprecollagen expressing,and the efficacy is positively correlated with its density.Danshen insection and tetramethylpyrazine have been used in animal experiments and clinical studies for preventing radioactivity lung injury which have given us some good results.Objective:To investigate the preventive efficacy of matrine on radiation pneumonitis in mice.Methods:44 mice were divided randomly into 4 groups:irradiation alone (RT),irradiation plus matrine(MRT),irradiation plus danshen insection(SRT), irradiation plus tetramethylpyrazine(LRT).The fight lungs of the mice were irradiated once with 6MV X-ray,and the radiation dose was 30Gy.The peritoneal cavity infusion started 2 days before irradiation for the medication groups until every observation point ended.The middle leaves of the right lungs were observed in general then made into microscope slides and given HE dyeing.We observed hyperemia of the capillaries,thickness of the alveolar septum,construction of the alveolus and effusion of the alveolar space with low microscope.We also counted the density of red blood cells(RBCD)and the density of karyotes(KD)with high microscope.Results:The radiation pneumonitis in MRT-group was lighter than the other three groups.The density of red blood cells(KD)and the density of karyotes(KD) of MRT-group were smaller than the other groups.The variability was more significant 8 weeks after irradiation(P＜0.01).The density of red blood cells(KD) and the density of karyotes(KD)of SRT-group and LRT-group were smaller than RT-group,but there were no statistical significance between the variables.Conclusion:Matrine can lessen radiation pneumonitis in mice,and its protective efficacy was better than danshen insection and tetramethylpyrazine. Objective:To investigate the dosimetric characteristics and the superiority of Helical Tomotherapy for non-small-cell lung cancer(NSCLC)through comparing the Helical Tomotherapy plans and intensity modulated radiation therapy(IMRT) plans.Methods:10 NSCLC patients were chosen for retrospective analysis.The CT images with the gross tumor volume(GTV),clinical target volume(CTV), planning target volume(PTV)and organs at risk(OARs)were transferred to PresisePlan planning system and TomoTherapy planning system respectively.The prescription doses were 70Gy/33F for GTV and GTVnd,and 60Gy/33F for CTV and CTVnd.95%of the targets' volumes should receive the prescription doses. The dose restrictions for the OARs were as follows:spinal cord＜45Gy,V20 of the total lungs＜30%,V50 of the heart＜50%and V55 of the esophagus＜50%.The two plans were evaluated by means of the dose coverage of the targets,dose-volume histogram(DVH)and other dosimetric index.Results:Dose coverage,conformity and homogeneity of the targets from both plans were found to be satisfactory,but those of Tomo plans were better than IMRT plans.The maximum dose of GTV for the Tomo plans was significantly lower than the IMRT plans(P＜0.01),but the mean dose was higher than the IMRT plans(P＞0.05).The maximum and the mean dose of PTV for the Tomo plans were both distinctly lower than the IMRT plans(P＜0.001 and P＜0.01).The V5 and V10 for both the ipsolateral lung and the heterolateral lung of the Tomo plans were higher than the IMRT plans(P＞0.05),but the V13,V15,V20,V25,V30,the maxiumum dose and the mean lung dose(MLD)were lower than the IMRT plans. The V5,V10 and V13 for the total lung of the Tomo plans were higher than the IMRT plans(P＞0.05),but the V15,V20,V25,V30 and MLD were lower than the IMRT plans.The maximum dose for the spinal cord of Tomo plans was lower than that of the IMRT plans(P＞0.05),but the mean dose was higher than the IMRT plans(P＜0.01).The maximum and the mean dose for the heart,esophagus and trachea of the Tomo plans were lower than those of the IMRT plans(P≥0.05).ConcLusion:Our studies show that Helical Tomotherapy plans can get better dose uniformity,dose gradient and savage for cord,heart,esophagus and trachea than intensity modulated radiation therapy plans,but the V5 and V10 of the ipsolateral lung,the heterolateral lung and the total lung are higher than IMRT plans.