摘要
目的探讨采用锥形束CT(CBCT)评价未手术宫颈癌患者适形调强放射治疗(IMRT)中肿瘤临床靶区(CTV)内界值的移动度,以期为未手术宫颈癌根治性放疗患者肿瘤CTV-ITV扩界值(IM)的设定提供参考。方法收集2013年12月至2014年10月未手术宫颈癌接受根治性IMRT的患者20例,比较CBCT与定位CT图像上肿瘤临床靶区的位移及形变情况。结果 20例宫颈癌患者140次CBCT图像上肿瘤临床靶区(CTV1-CBCT)相对于定位CT上CTV1形变体积为(33.56±22.52)cm^3(范围:1.04~110.22 cm^3),CTV1-CBCT相对于CTV1形变体积百分比为(10.19±6.32)%(范围:0.37%~32.01%)。患者140次CBCT扫描中,CTV1在宫体及宫旁前、宫体及宫旁后、宫颈前、宫颈后、宫体上、宫体偏侧、宫体对侧7个方位最大形变长度分别为(1.19±0.82)cm、(0.80±0.55)cm、(0.16±0.25)cm、(0.23±0.29)cm、(0.27±0.42)cm、(0.18±0.24)cm及(0.78±1.09)cm。<2 cm的肿瘤IM只能使85%的CBCT扫描次数实现CTV1-CBCT完全覆盖;95%以上的CBCT扫描中宫体形变大于宫颈形变;患者间肿瘤临床靶区运动度有个体差异。结论应用CBCT获得三维方向不同大小IM和宫颈及宫体不同大小IM的靶区勾画策略并配合个体化的图像引导放疗策略可能是目前宫颈癌精确放疗较好的临床实现形式。
Objective To investigate the motion of clinical target volume（ CTV） by using cone beam computed tomography（ CBCT） on linear accelerator and to determine a internal margin（ IM） value for the internal target volume（ ITV） during intensity-modulated radiotherapy（ IMRT） for non-surgical cervical cancer. Methods One hundred and forty CBCT images from 20 non-surgical cervical cancer patients who underwent radical IMRT from Dec 2013 to Oct 2014 were selected for this study. The deformation and displacement between the simulation CT and CBCTs were measured. Results The volume reductions of CTV1 between the simulation CT and CBCTs were（ 33. 56 ± 22. 52） cm3（ range from 1. 04-110. 22 cm3） and the percentages of the volume reductions were（ 10. 19 ± 6. 32） %（ range from 0. 37%-32. 01%）. The motion between the simulation CT and CBCTs were（ 1. 19 ± 0. 82） cm,（ 0. 80 ± 0. 55） cm,（ 0. 16 ± 0. 25） cm,（ 0. 23 ±0. 29） cm,（ 0. 27 ±0. 42） cm,（ 0. 18 ±0. 24） cm and（ 0. 78 ±1. 09） cm in the anterio-posterior directions of uterus,anterio-posterior directions of cervix,superior directions of uterus,lateral directions of the same side,the opposite side of the bottom of uterus,respectively. If the IM was set less than 2 cm,the CTV of 85% CBCTs could be covered completely. 95% patients showed greater uterus motions than cervical motions in all directions. The motion of CTV1 had great individual difference. Conclusion The strategies of target outline for different IM size at three dimensional direction obtained by CBCT and different IM size of uterus and cervix,in combination with individualized image guided radiotherapy may be a good clinical form for realizing precise radiotherapy in cervical cancer.
出处
《临床肿瘤学杂志》
CAS
2016年第4期329-335,共7页
Chinese Clinical Oncology
基金
湖南省科技厅资助项目(2014FJ3102)
关键词
未手术宫颈癌
适形调强放射治疗
锥形束CT(CBCT)
临床靶区
靶区移动
Non-surgical cervical cancer
Intensity modulation radiated therapy（IMRT）
Cone beam computed tomography（CBCT）
Clinical target volume（CTV）
Internal margin（IM）
