Application Of Image-Guided Radiotherapy In Non Small Cell Lung Cancer

Objective: To compare the dosimetrie difference between Image GuidedRadiation Therapy (IGRT) and intensity modulated radiation therapy (IMRT)for non small cell lung cancer (NSCLC) radiotherapy. Analysis the radiationtoxicity and the short-term clinical efficacy and the prognosticfactors.Methods: Collect52NSCLC patients accept IGRT and55NSCLCpatients accept IMRT, target prescription dose requirements are meet (95%volumn accept at least95%target prescription dose)． According to Dosevolume histogram(DVH) made the comparison between the two plans forfractionation dose, accumulation dose and dose-volume histogram of bothlung, spinal-cord, heart, PTV. And analysis the radiation toxicity and theshort-term clinical efficacy, adopts the SPSS17.0statistical software for dataanalysis.Results:(1) There were significant differences between two group,the max, min and mean dose of PTV in IGRT group is higher than IMRTgroup,(P<0.05). the total lung V5, V10, V20, V30, V50,the heart max doseand spinal max dose were in IGRT group all smaller than IMRT group(P<0.05)there were significant differences between two group.(2) The incidence of theradiation toxicity in IGRT group was lower than IMRT group,(P<0.05).Whilethe rent effective rate of IMRT and IGRT group were63.7and69.3,there wereno differences between them (P>0.05).(3) In group IGRT,1-,1.5-,2-yearsurvival rate and mediansurvival time were57.7%、41.8%、22.8%and16.5month; In group IMRT, they were54.5%、34.6%、19.5%and14.3months,respectively.(4) With univariate analysis, metastasis ofradiation-related pneumonitis(RP), short-time response, after radiotherapychemotherapy times were significantly associated with OS,p<0.05; Otherfactors, such as age, smoking status, clinical stage, tumor maximum size, styleof radiotherapy, radiation-related esophagitis,were not related with OS(p>0.05).With multivariate analysis, the independent prognostic factors were radiation-related pneumonitis, short-time response, the chemotherapy times ofpostradiotherapy Conclusion:(1)Using IGRT can reduce PTV externalexpansion, increase PTV dose，reduce the mean dose of total lung, Reduce thenormal tissue dose. Provide the quality assurance to improving the clinicaloutcomes and reducing the radiotherapy complications.(2)With multivariateanalysis, the independent prognostic factors were radiation-relatedpneumonitis, short-time response, the chemotherapy times of postradiotherapy...