Adli M, Garipagaoglu M, Kocak Z
Department of Radiation Oncology, School of Medicine, Gaziantep University, Gaziantep, Turkey.
Br J Radiol. 2009 Mar;82(975):243-8. doi: 10.1259/bjr/90233932. Epub 2008 Dec 8.
The purpose of this study was to assess the impact of bladder volume on bladder base doses during gynaecological intracavitary high dose rate (HDR) brachytherapy. 42 different intracavitary HDR brachytherapy applications (tandem and ovoid, 25; ovoid, 17) were performed in 41 patients treated for cervical (n = 29) and endometrial (n = 12) cancer. The International Commission on Radiation Units and Measurements (ICRU) bladder reference point (BRP) dose and doses of 17 points selected on the bladder base were calculated using planning orthogonal radiographs taken after applicator placement with 100 ml and 270 ml bladder volumes. The effect of bladder volume on ICRU BRP and bladder base maximum point (BBMP) doses were analysed for both types of applications. Median ICRU BRP doses (in percentage of prescription dose) were 36.2% (18.2-69.8%) and 40.0% (21.0-61.8%) for ovoid applications (p = 0.13) and 34.9% (15.7-81.0%) and 33.8% (16.5-88.1%) for tandem and ovoid applications (p = 0.48) in 100 ml and 270 ml bladder volumes, respectively. Median BBMP doses were 75.1% (33.8-141.0%) and 104.0% (62.8-223.0%) for ovoid applications (p<0.001) and 116% (51.2-242.0%) and 124.0% (62.0-326%) for tandem and ovoid applications (p = 0.018) in 100 ml and 270 ml bladder volumes, respectively. Although the BBMP dose significantly increases, the ICRU BRP dose does not change with increasing bladder volume in gynaecological intracavitary HDR brachytherapy. Increasing bladder volume increases bladder base maximum dose in intracavitary gynaecological brachytherapy.
本研究的目的是评估妇科腔内高剂量率（HDR）近距离放射治疗期间膀胱体积对膀胱底部剂量的影响。对41例宫颈癌（n = 29）和子宫内膜癌（n = 12）患者进行了42次不同的腔内HDR近距离放射治疗（串珠状施源器和卵圆形容器，25次；卵圆形容器，17次）。使用施源器放置后拍摄的计划正交X线片，分别计算膀胱体积为100 ml和270 ml时国际辐射单位与测量委员会（ICRU）膀胱参考点（BRP）剂量以及在膀胱底部选择的17个点的剂量。分析了两种类型的治疗中膀胱体积对ICRU BRP和膀胱底部最大点（BBMP）剂量的影响。对于卵圆形容器治疗，膀胱体积为100 ml和270 ml时，ICRU BRP剂量中位数（占处方剂量的百分比）分别为36.2%（18.2 - 69.8%）和40.0%（21.0 - 61.8%）（p = 0.13）；对于串珠状施源器和卵圆形容器治疗，分别为34.9%（15.7 - 81.0%）和33.8%（16.5 - 88.1%）（p = 0.48）。对于卵圆形容器治疗，膀胱体积为100 ml和270 ml时，BBMP剂量中位数分别为75.1%（33.8 - 141.0%）和104.0%（62.8 - 223.0%）（p<0.001）；对于串珠状施源器和卵圆形容器治疗，分别为116%（51.2 - 242.0%）和124.0%（62.0 - 326%）（p = 0.018）。在妇科腔内HDR近距离放射治疗中，尽管BBMP剂量随膀胱体积增加而显著增加，但ICRU BRP剂量并不随膀胱体积变化。在腔内妇科近距离放射治疗中，膀胱体积增加会使膀胱底部最大剂量增加。
