Clinical Study On The Prevention Of Radioactive Pneumonia In Small Cell Lung Cancer By "timely And Multiple" Technique

Objective To investigate the value of using “timely and repeatedly”shrinking-field technique for preventing radiation pneumonitis(RP).Methods 52 patiens with histologic or cytologically proven small cell lung cancer were included in this study.Radiotherapy was delivered in 2Gy daily fraction to a total dose of 60 Gy.All of sixteen patients received three times simulation CT scan.one repeat CT scan were performed at 30 Gy and 50 Gy at two repeat CT scan. According three CT data, three treamen plan were designed,called plan1、plan2、 plan3, respectively. Comparisons were executed between three plans in the changes of GTV、V5、V10、V15、V20、V25、V30.Results The value of GTV and Vdose were all reduced obviously in plan2 and plan3,there were significant difference in plan1 and plan2(p < 0.05).Two patients occurred radiation pneumonitis(RP),the ratio of RP is 11.5% in this research.Conclusions “Timely and repeatedly”shrinking-field technique likely decrease the ratio of RP in patients with SCLC,and lately effect is better.