CAJ | 학술논문

目的探讨图像引导放疗技术应用于胸腹部肿瘤大分割放疗以提高治疗精度,测最其摆位误差并确定由内靶体积(ITV)外放产生计划靶体积(PTV)的间距.方法入组24例胸腹部肿瘤病例,采用大分割放疗,每次治疗前行锥形束CT扫描,在线校正摆位误差并记录误差值.统计校正前后的误差数据,采用二参数法计算由ITV外扩产生PTV间距.结果校正前摆位平移误差在左右(x)、头脚(y)和腹背(z)方向I:分别为(2.1±2.0)、(3.9±3.2)、(2.9±2.8)mm,校正后分别为(0.8±0.7)、(0.9±0.7)、(0.9±0.7)mm;外扩间距校正前分别为5.6、10.2、7.7 mm,校正后分别为2.1、2.3、2.3 mm.旋转角度误差校正前后无变化,校正前头脚方向误差大于左右和腹背方向,校正后3个方向误差之间尤差别.结论图像引导放疗通过在线校位能有效减小摆位误差并能观测肿瘤及周围组织器官位移和变形,计算在线校位后的靶区外放间距可以为PTV确定提供参考.
목적 탐토도상인도방료기술응용우흉복부종류대분할방료이제고치료정도,측최기파위오차병학정유내파체적(ITV)외방산생계화파체적(PTV)적간거.방법 입조24례흉복부종류병례,채용대분할방료,매차치료전행추형속CT소묘,재선교정파위오차병기록오차치.통계교정전후적오차수거,채용이삼수법계산유ITV외확산생PTV간거.결과 교정전파위평이오차재좌우(x)、두각(y)화복배(z)방향I:분별위(2.1±2.0)、(3.9±3.2)、(2.9±2.8)mm,교정후분별위(0.8±0.7)、(0.9±0.7)、(0.9±0.7)mm;외확간거교정전분별위5.6、10.2、7.7 mm,교정후분별위2.1、2.3、2.3 mm.선전각도오차교정전후무변화,교정전두각방향오차대우좌우화복배방향,교정후3개방향오차지간우차별.결론 도상인도방료통과재선교위능유효감소파위오차병능관측종류급주위조직기관위이화변형,계산재선교위후적파구외방간거가이위PTV학정제공삼고.
Objective To study image-guided hypofractionated radiotherapy for thoracic and abdominal tumors,and to determine the margins extended from internal target volume(ITV) to planning target volume(PTV). Methods Twenty-four patients who received image-guided hypofractionated radiotherapy for thoracic and abdominal tumors were included in this study. X-ray cone beam CT was regularly performed before the treatment. The shift and Rotation in right-left ( R-L), superior-inferior(S-I) and anterior-posterior (A-P) directions were recorded and analyzed. The shift margin from ITV to PTV was calculated with the equation,margin =2'mean+0.7'standard deviation. Results Before online correction,the shift errors in R-L,S-I and A-P directions were [2.1±2.0] mm, [3.9±3.2] mm and [2.9±2.8] mm,and the corresponding margins were 5.6 mm, 10.2 mm and 7.7 mm. After the correction the shift errors were [0.8±0.7] mm, [0.9±0.7] mm and [0.9±0.7] mm, and the margins were 2.1 mm,2.3 mm and 2.3 mm. The set-up error was markedly decreased after the correction. There was no change in rotation after the correction. Conclusions The positioning error decreases after the correction in IGRT,and the precision of radiotherapy is improved. Measuring set-up error in radiotherapy can provide institution-specific margins for PTV designing.