Dosimetric Characteristic Study Of Stereotactic Body Radiation Therapy For Stage ? Non-small Cell Lung Cancer

Lung cancer is one of the most common malignant tumor in C hina,and the first of the mortality rate in malignant tumor.Early non-small-cell lung cancer(NSCLC)accounts for about 30% of all NSCLC,surgery is the first choice for early NSCLC,but due to age,tumor location,or personal reasons Etc,some patients can not surgery,radiation therapy is the preferred treatment for these patients.Developed in recent years based on the technology of modern radiotherapy stereotactic body radiotherapy(SBRT),a short course of treatment,high single dose and biological effective dose(BED)high,local control rates high,etc.Because SBRT single dose and biological effective dose is very high,so for this kind of relatively special radiation therapy technology to strictly limit the normal tissue dose,reduce related radiation damage and complications.Thesis studied the respiratory gating technology and non-coplanar technology in the dosimetry characteristics of SBRT.At first for patients did respiratory gating location and breathe freely location respectively,and observe the patient's respiratory movement amplitude under conventional simulator.Through the target volume,OARs dose and target parameters comparison found that respiratory gating location sketch target while in GTV and CTV is greater than the free breathing location,but obviously reduces the volume of PTV(P = 0.000);Apply the same conditions of SBRT plan in ter ms of OARs dose,respiratory gating location illuminated dose to reduce most O ARs dose.In the ill side of lung and whole lung V2.5,V5,V20,V25,Dmean dose,and the Dmean dose of the health side of lung,respiratory gating Plan(Plan-RPM)are less than breathe freely Plan(Plan-FB),the spinal cord and chest wall irradiation Dmax without statistical significance difference,the others all had statistical significance difference(P < 0.05),the Plan-RPM reduce most of OARs dose;Dosimetry parameters of the target area,CI and HI there was no statistically significant difference.A further comparison of the coplanar SBRT Plan(Plan-Co)and non-coplanar SBRT Plan(Plan-Non)dosimetry compared,non-coplanar while increase the ill side of lung and whole lung V2.5,V5 and the ill side of lung Dmean dose,but reduce the ill side of lung and whole lung V20,V25,and the healthy lung Dmean,increase the dose gradient of SBRT Plan,at the same time also reduces the spinal cord,esophagus,trachea,chest wall endanger the exposure dose,only the dose of the heart has no statistical difference between the two kinds of plan.Target dosimetry parameters sides,non-coplanar raised the CI of the target,there was no statistically significant difference between the HI.The combination of the two technologies in terms of dosimetry has obvious advantages,in the stereotactic body radiation therapy of stage?NSCLC is worthy promoting.