CT based three dimensional dose-volume evaluations for high-dose rate intracavitary brachytherapy for cervical cancer
CT based three dimensional dose-volume evaluations for high-dose rate intracavitary brachytherapy for cervical cancer
复制标题
DOI：
10.1186/1471-2407-14-447
复制
发表时间：
2014-06-17
期刊：
影响因子：
3.8
通讯作者：
Itami, Jun
中科院分区：
文献类型：
--
作者：
Murakami, Naoya;Kasamatsu, Takahiro;Itami, Jun
背景：本研究根据高剂量率腔内近距离放射治疗（HDR-ICBT）时的CT图像，回顾性绘制符合GEC-ESTRO指南的高危临床靶体积（HR-CTV），并分析临床转归与HR-CTV剂量的相关性。方法：我们的研究人群包括51例宫颈癌（IB-IVA期）患者，接受50 Gy外束放疗（EBRT），使用中心屏蔽联合2-5次6 Gy HDR-ICBT，每周或不使用顺铂。剂量计算基于曼彻斯特系统，对a点给予6 Gy的规定剂量。回顾每次HDR-ICBT时的CT图像并绘制hr - ctv轮廓。采用线性二次模型（α / β = 10 Gy）将剂量换算为2 Gy当量剂量（EQD(2)）。结果：3年总生存率、无进展生存率和局部控制率分别为82.4%、85.3%和91.7%。HR-CTV D-90的中位累积剂量为65.0 Gy （52.7-101.7 Gy）。第一次ICBT时HR-CTV从串联到最外侧边缘的中位长度为29.2 mm（范围为18.0-51.9 mm）。在单变量分析中，对于HR-CTV的D-90≥60 Gy的患者，LCR和PFS均显著有利（p分别= 0.001和0.03）。首次ICBT时HR-CTV从串联到边缘的最大长度小于3.5 cm的患者PFS显著有利（p = 0.042）。结论：宫颈癌CT近距离放射治疗的体积剂量与临床疗效有关。
Background: In this study, high risk clinical target volumes (HR-CTVs) according to GEC-ESTRO guideline were contoured retrospectively based on CT images taken at the time of high-dose rate intracavitary brachytherapy (HDR-ICBT) and correlation between clinical outcome and dose of HR-CTV were analyzed.Methods: Our study population consists of 51 patients with cervical cancer (Stages IB-IVA) treated with 50 Gy external beam radiotherapy (EBRT) using central shield combined with 2-5 times of 6 Gy HDR-ICBT with or without weekly cisplatin. Dose calculation was based on Manchester system and prescribed dose of 6 Gy were delivered for point A. CT images taken at the time of each HDR-ICBT were reviewed and HR-CTVs were contoured. Doses were converted to the equivalent dose in 2 Gy (EQD(2)) by applying the linear quadratic model (alpha/beta = 10 Gy).Results: Three-year overall survival, Progression-free survival, and local control rate was 82.4%, 85.3% and 91.7%, respectively. Median cumulative dose of HR-CTV D-90 was 65.0 Gy (52.7-101.7 Gy). Median length from tandem to the most lateral edge of HR-CTV at the first ICBT was 29.2 mm (range, 18.0-51.9 mm). On univariate analysis, both LCR and PFS was significantly favorable in those patients D-90 for HR-CTV was 60 Gy or greater (p = 0.001 and 0.03, respectively). PFS was significantly favorable in those patients maximum length from tandem to edge of HR-CTV at first ICBT was shorter than 3.5 cm (p = 0.042).Conclusion: Volume-dose showed a relationship to the clinical outcome in CT based brachytherapy for cervical carcinoma.