Analysis Of Prognosis And It Related Factors For Stage Ⅲ Non-small Cell Lung Cancer After Three-dimensional Conformal Radiotherapy (3D-CRT)

Objective: To retrospectively evaluate treament outcome and its relatedprognostic factors for stage III non-small cell lung cancer (NSCLC) afterthree-dimensional conformal radiotherapy(3D-CRT);To compare of prognosis,toxicity and dose distribution of target during different treatment time.Method: From August2000to December2004and October2006toDecember2008,213patients with stage III NSCLC were reviewed; Amongthem,84cases with stage IIIA,129cases with stage IIIB; males in170andfemale in43cases. There were74cases treated with radiotherapy alone,92cases with concurrent chemoradiotherapy, and45cases with sequentialchemoradiotherapy. The median dose was62Gy(50～78Gy).Of the203caseswho had complete radiation treatment plannings,72cases who treated fromAugust2000to December2004was defined as group A,131who fromOctober2006to December2008was defined as group B. Radiotherapy effect,radiation related toxity were assessed by SPSS13.0software; Aslo, physicalparameters such as GTV, CTV, PTV were evluated with DVH by TPS.Result: The deadline of the follow-up was31December2011, and thefollow-up rate was94.4%. For all patients, the median and mean survival timewas15months and27.9months respectively.1-,2-and3-year overall survivalwas54.8%,35.4%,18.9%. There was51.2%(109/213) with acuteradiation-related pneumonitis, grade1in140cases,grade2in25cases,39cases in grade3, grade4in5cases, respectively; There was41.3%(88/213)with acute radiation esophagitis rate,47cases in grade1,37cases in grade2,3cases in grade3.With univariate analysis, number of radiation field, N stage,tumor volmle, metastasis of supraclavicular lymph nodes, radiation-relatedpneumonitis, short-time response, GTV, GTVD100, GTVV60, CTV, CTVD100, PTV, PTVD95, PTVV60were significantly associated with OS,p<0.05; Other factors,such as age, smoking status, clinical stage, tumormaximum size, chemotherapy, dose of radiotherapy, style of radiotherapy,radiation-related esophagitis, GTVDmean, PTVDmean, GTVD95, GTVD90,GTVV65,CTVDmean, CTVD95, CTVD90, CTVV65, PTVD90, PTVV65were not related with OS (p>0.05).With multivariate analysis, the independentprognostic factors were radiation-related pneumonitis, short-time response andtumor volume.203patients who had complete radiation treatment planningsentered subgroup analysis. In group A,1-,2-,3-year survival rate and mediansurvival time after3D-CRT were45.8%,29.2%,15.3%and10.2months; Ingroup B, they were59.3%,37.8%,20.8%, and18months (x2=4.293, p=0.036)respectively; The incidence of acute radiation pneumonitis and esophagitis ingroup A was significantly higher than in group B, p<0.05. There were nodifferences between group A and group B for clincal data and GTV, CTV, PTV,p>0.05; GTVDmax, CTVDmax, PTVDmax, GTVDmean, CTVDmean,PTVDmean, GTVV65, CTVV65, PTVV65, were higher in group A than ingroup B, p<0.000; but GTVV50, CTVV50, CTVD95,PTVD100, PTVD95,PTVD90, PTVV55, PTVV50, were lower in group A, p<0.00; for GTVD100,GTVD95, GTVD90, GTVV60,GTVV55, CTVD90, CTVV55, it was higher ingroup A than in group B, p>0.05.For lung, Dmean, V15, V20, V25, V30, V35,V40were higher in group A, and the difference was statistically significant (p<0.000). LungV5, V10of group A was higher than that of group B(p>0.05).For heart, Dmax, Dmean, V55, V50, V45, V40was higher in groupA than in group B, and the difference was statistically significant, p <0.05.Aslo, Dmax, Dmean, V45, V40of spinal cord was higher in group A.Conclusions:3D-CRT could be tolerate for local advanced NSCLC.There were better prognosis for patients with good short time response, smalltumor volume, and grade1-2acute radiation-related pneumonitis after3D-CRT.3D-CRT combined with chemotherapy did not improve survivalfutherly. Accompanied with improved technique of3D-CRT, the dosedistribution of tumor target was more reasionable. Dose of radiothearpy was decreased and toxicity was reduced in NSCLC, but its prognosis might beimproved.