Jones Nathan D, Rankin Jim, Gaffney David K
Department of Radiation Oncology and Huntsman Cancer Institute, University of Utah Medical Center, 1950 Circle of Hope, Salt Lake City, UT 84112, USA.
Brachytherapy. 2004;3(3):120-4. doi: 10.1016/j.brachy.2004.07.001.
To evaluate the dose variation in high-dose-rate (HDR) intracavitary brachytherapy for cancer of the cervix when treatment planning is performed prior to each applicator insertion versus when the initial plan is used for each treatment.
Fourteen patients with carcinoma of the cervix were treated with chemoradiotherapy followed by five intracavitary tandem and ovoid insertions of 600 cGy/fraction. We modified the actual plans to calculate the dose each dose point would have received using only the treatment plan created for the initial fraction.
An increase in the percent dose to the rectum, bladder, and vaginal surface of 5%, cGy (p = 0.038), 6% (p = 0.006), and 11%, respectively, were observed when the initial treatment plan was used versus using the optimized treatment plan for each insertion. The greatest single change resulted in a percent increase of 35%, 30%, and 45% to the rectum, bladder, and vaginal surface points, respectively.
Increased dose to at-risk structures occurred when individualized treatment planning was not performed. Since a significant increase in dose to the rectum (p = 0.038) and bladder (p = 0.006) was obtained without customized treatment planning, we continue to advocate individualized treatment planning in HDR tandem and ovoid insertions for the treatment of cervix cancer.
评估在高剂量率（HDR）腔内近距离放射治疗宫颈癌时，每次施源器插入前进行治疗计划与每次治疗都使用初始计划时的剂量变化情况。
14例宫颈癌患者接受了放化疗，随后进行了5次腔内串联和卵圆体插入治疗，每次剂量为600 cGy/分次。我们修改了实际计划，以仅使用为初始分次创建的治疗计划来计算每个剂量点所接受的剂量。
与每次插入时使用优化治疗计划相比，使用初始治疗计划时，直肠、膀胱和阴道表面的剂量百分比分别增加了5%、cGy（p = 0.038）、6%（p = 0.006）和11%。最大的单次变化分别导致直肠、膀胱和阴道表面点的剂量百分比增加了35%、30%和45%。
未进行个体化治疗计划时，危及结构的剂量会增加。由于在没有定制治疗计划的情况下，直肠（p = 0.038）和膀胱（p = 0.006）的剂量有显著增加，我们继续提倡在HDR串联和卵圆体插入治疗宫颈癌时进行个体化治疗计划。
