CAJ | 학술논문

目的：应用IGRT技术观察膀胱、直肠在治疗中变化，分析其对治疗影响。方法入选18例接受根治性IMRT的前列腺癌患者，共行CBCT在线校正治疗体位247次。在模拟CT和CBCT图像上勾画CTV、膀胱及直肠，观察膀胱、直肠体积和位置变化。将x、y、z轴方向平移摆位误差引入TPS中重新计算得到PTV、膀胱体积（ BV）、直肠体积（ RV）等剂量体积参数，分析各参数对治疗的影响。对再计划与原计划结果行配对t检验，采用Pearson相关法分析膀胱、直肠位移和膀胱、直肠体积对靶区受量影响。结果治疗过程中膀胱和直肠充盈度有较大变化，其中原计划与再计划PTVD95％为7777．37 cGy ∶7628．56 cGy （P＝0．027），PTV Dmin为87．91 cGy ∶83．35 cGy （P＝0．000），RVP 为5．89％∶8．31％（ P＝0．000）。 PTVD95％与膀胱、直肠移动具有相关性（ r＝0．296、0．177）。直肠体积与PTVD95％有一定相关性（ r＝0．115）。对PTV Dmin而言，除上述各指标之外，与膀胱体积有一定相关性（ r＝?0．128）。结论在前列腺癌IMRT中，使膀胱、直肠尤其是后者尽量复原定位时状态对保证靶区受量及减少直肠受照有明显意义。
목적：응용IGRT기술관찰방광、직장재치료중변화，분석기대치료영향。방법입선18례접수근치성IMRT적전렬선암환자，공행CBCT재선교정치료체위247차。재모의CT화CBCT도상상구화CTV、방광급직장，관찰방광、직장체적화위치변화。장x、y、z축방향평이파위오차인입TPS중중신계산득도PTV、방광체적（ BV）、직장체적（ RV）등제량체적삼수，분석각삼수대치료적영향。대재계화여원계화결과행배대t검험，채용Pearson상관법분석방광、직장위이화방광、직장체적대파구수량영향。결과치료과정중방광화직장충영도유교대변화，기중원계화여재계화PTVD95％위7777．37 cGy ∶7628．56 cGy （P＝0．027），PTV Dmin위87．91 cGy ∶83．35 cGy （P＝0．000），RVP 위5．89％∶8．31％（ P＝0．000）。 PTVD95％여방광、직장이동구유상관성（ r＝0．296、0．177）。직장체적여PTVD95％유일정상관성（ r＝0．115）。대PTV Dmin이언，제상술각지표지외，여방광체적유일정상관성（ r＝?0．128）。결론재전렬선암IMRT중，사방광、직장우기시후자진량복원정위시상태대보증파구수량급감소직장수조유명현의의。
Objective To observe the motions of the rectum and bladder by image?guided radiotherapy ( IGRT) and to analyze their impact on treatment. Methods Eighteen patients with prostate cancer undergoing intensity?modulated radiotherapy ( IMRT) were enrolled in the study and 247 cone?beam computed tomography ( CBCT) images were obtained from this study. The clinical target volume, bladder, and rectum were contoured on all simulated CT and CBCT to examine their volume and position changes. The dose distributions were recalculated based on the data of the x?, y?, and z?axis setup errors. The doses to planning target volume ( PTV) and organs at risk were calculated in the replanning, and their impact on treatment was analyzed. Comparison of the planning and replanning results was made by paired t?test. The effects of displacements and volumes of the bladder and rectum on target doses were analyzed by Pearson correlation method. Results Great changes in the volumes of the bladder and rectum were observed during the treatment. For the planning and replanning results, PTVD95% was 7777. 37 cGy vs. 7628. 56 cGy ( P=0. 027), PTV Dmin was 87. 91 cGy vs. 83. 35 cGy (P=0. 000), and RVP was 5. 89% vs. 8. 31%(P=0. 000). There were correlations between PTVD95% and the motions of the bladder and rectum, with correlation coefficients of 0. 296 and 0. 177, respectively. The correlation coefficient between rectal volume and PTVD95% was 0. 115, indicating a certain correlation. There is a certain correlation between and PTV Dmin and bladder volume, with a correlation coefficient of?0. 128. Conclusions The recovery of the state during localization for the bladder and rectum, especially the latter, has great significance to ensure the target dose and reduce exposure of the rectum in the IMRT for prostate cancer.