Correlation Between Bladder Volume and Irradiated Dose of Small Bowel in CT-based Planning of Intracavitary Brachytherapy for Cervical Cancer
Correlation Between Bladder Volume and Irradiated Dose of Small Bowel in CT-based Planning of Intracavitary Brachytherapy for Cervical Cancer
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DOI：
10.1093/jjco/hyr203
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发表时间：
2012-04-01
影响因子：
2.4
通讯作者：
Ohtomo, Kuni
中科院分区：
文献类型：
--
作者：
Yamashita, Hideomi;Nakagawa, Keiichi;Ohtomo, Kuni
为量化膀胱容量对宫颈癌CT治疗计划中腔内后装治疗剂量分布的影响，对10例宫颈癌患者进行了高剂量率腔内后装治疗。对于三维分析，盆腔计算机断层扫描获得的患者留置导管的位置，并从患者接受了50，100，150和200 cc的无菌水注射到他们的膀胱（o200 cc'被定义为全膀胱）。另外，扫描是在充满膀胱的俯卧位进行的，膀胱充盈显著影响小肠和膀胱的剂量。在所有热点因素中，膀胱排空时小肠最大剂量的中位数显著更高（D-2cc为480 vs. 256 cGy）。尽管剂量测定显示较大膀胱体积（D-50和V-25）的剂量较低，但膀胱充盈时的中位最大剂量显著更高（D-2cc为420 cGy vs. 775 cGy）。直肠乙状结肠剂量不受膀胱扩张的影响（D-2cc为476 vs. 467 cGy）。改变为俯卧位后，小肠的热点剂量没有改变，但膀胱的热点剂量显著降低，尽管这一过程非常困难，膀胱体积的增加导致小肠的热点剂量显著降低，但膀胱的热点剂量增加，而不改变直肠乙状结肠的剂量分布。
To quantify the effect of bladder volume on the dose distribution of intracavitary brachytherapy in computed tomography-based treatment planning for cervical cancer.Ten patients with cervical cancer were treated with high-dose rate radiation brachytherapy. For the three-dimensional analysis, pelvic computed tomographic scans were obtained from patients with indwelling catheters in place and from patients who received 50, 100, 150 and 200 cc injections of sterile water into their bladders (o200 cc' was defined as a full bladder). Additionally, scans were made in the prone position with the full bladder.Bladder fullness significantly affected the dose to the small bowel and bladder. The median of maximal doses to the small bowel was significantly greater with an empty bladder in all factors of hot spot (480 vs. 256 cGy on D-2cc). Although dosimetry revealed lower doses for larger volumes of bladder (D-50 and V-25), the median maximal dose to the bladder was significantly greater with a full bladder (420 vs. 775 cGy on D-2cc). The rectosigmoid doses were not affected by bladder distension (476 vs. 467 cGy on D-2cc). After changing to the prone position, the hot spot dose of small bowel did not change but that of the bladder significantly decreased, although this procedure was very difficult.An increase in bladder volume resulted in a significant reduction in the hot spot dose of the small bowel at the expense of an increase in that of the bladder without changing the dose distribution of the rectosigmoid.