摘要
目的在前列腺癌三维适形放疗中，研究对比膀胱充盈和排空状态下靶区和周边重要器官体积改变以及照射剂量变化。方法临床穿刺细胞学证实的前列腺癌早期（T1～T2NOM0期）病例10例，无严重合并症，行对称6个野三维适形放疗。CT定位前1．0．0．5h口服稀释造影剂各400ml。定位时留置导尿，排空膀胱后仰卧位CT全盆腔定位扫描，然后注入稀释造影剂250～300ml充盈膀胱，再次CT定位扫描。CT影像上勾画前列腺靶区和周围重要器官轮廓，三维计划设计。分别评估CTV，PTV、直肠、膀胱、股骨头和盆腔小肠体积，CTV、PTV、直肠、膀胱、股骨头、盆腔小肠平均照射剂量，以及50Gy膀胱、直肠，30Gy股骨头受照体积和盆腔小肠最大照射剂量，对比不同膀胱充盈状态下各器官结构体积变化以及照射剂量差别。结果与膀胱排空相比膀胱充盈使体积增加了499％，分别为（67±9）、（336±48）ml（P=0．000），CTV、PTV、直肠、股骨头、盆腔小肠的变化无统计学意义（P=0．153、0．501、0．929、0．771、0．081）。充盈时膀胱受照剂量仅为排空时的35％，分别为（1501±201）、（4267±216）eGy（P=0．000）；盆腔小肠受照剂量下降了75％，分别为（257±223）、（60±25）eGy（P=0．012）；CTV、PTV、直肠、股骨头的变化无统计学意义（P=0．423、0．540、0．123、0．704）。照射50Gy的膀胱体积因膀胱充盈减少了14％（P=0．001），直肠、股骨头的变化无统计学意义（P=0．675、1．000），盆腔小肠最大照射剂量仅为排空状态下的10％（P=0．004）。结论前列腺癌三维适形放疗中膀胱充盈状态对膀胱体积有影响，与膀胱排空相比膀胱充盈能减少膀胱、盆腔小肠照射剂量，对膀胱、盆腔小肠起一定保护作用。
Objective In prostate cancer treated with three-dimensional eonformal radiation therapy （3DCRT） ,we tried to prospectively assess the impact of the filling status of bladder on the volume and the integral dose distribution to the target and surrounding critical organs. Methods Ten patients with stage T1-T2NOM0 prostate cancer were studied. All patients received 3DCRT to the prostate and inferior seminal vesicle. One hour before CT simulation, the bladder was first voided, and then 400 ml of oral contrast solution was given at every half hour before the CT scan. Urethral catheterization was used for voiding or distending the bladder. When distending the bladder, 250-300 ml of contrast was injected into the bladder with the patient fixed at the supine position. Two sets of transverse images were taken for the whole pelvis in empty and full bladder. After the target and critical organs （ bladder, rectum, pelvic small bowel, and femoral heads） were contoured, a treatment plan of three-dimensional conformal radiotherapy was made using the CMS Foeus-Xio treatment planning system. The volume and mean doses of CTV, PIN, rectum, bladder, femoral heads, and small bowel with the bladder empty and full were evaluated. The percentage of volume which received 50 Gy in the rectum and bladder, 30 Gy in the femoral heads, and the maximal dose to the pelvic small bowel were also assessed . The variability of volume and dose distribution in these targets or organs was compared between the emply arnl full bladder status.Results comparing to the bladder empty stutus.full bladder led to a mean increase of 499% in the bladder volume,（67±9）ml and（336±48）ml （P=0.000）.respetivcly.No volume change was found in the CTV,PTV ,rectum,femoral heads and pelvic small bowel（P=0.153,0.501,0.929,0.771,0.081）.The mcan dose to the bladder in full status was only 35% of that in emply status.（1501±201） cGy and （4267±216） cGy （P=0.000） ,respectively.The mean dose to the pelvie small bowel was reduced by 75% in the full bladder status,（257±223） cGy and （60±25） cGy（P=0.012）,respectivcty.No dose change was found in the CTV, PTV,femoral heads and rectum （P=0.423,0.540,0.123,0.704）.From empty to full.dose volume bistogram（DVH） comparison showed 14% reduction in the percentage of bladder which recived 50 cGy（P=0.001）,without change in rectum and femoral heads （P=0.675,1.000）.The maximal dose to the pelvic small bowel in the full bladder status was only 10% of the empty status（P=0.004）.Conclusions When lreating prostate cancer with 3DCRT.the filling status of the bladder would result in the change bladder volume.Distended bladdcr is able to reduce the lradiation dose to the bladder.pelvie small bowet.thus brings up a better protection to these organs.
出处
《中华放射肿瘤学杂志》
CSCD
北大核心
2007年第1期48-51,共4页
Chinese Journal of Radiation Oncology
关键词
前列腺肿瘤/放射疗法
三维适形放疗
膀胱充盈或排空对靶区和器官的影响
prostate neoplasms/radintherpy
Three-dimensional
three-dimensional conformai radiation therapy
Bladder full empty is larget organ effect
