Department of Radiation Oncology, Hillman Cancer Center, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
Department of Gynecologic Oncology, Hillman Cancer Center, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
Int J Radiat Oncol Biol Phys. 2019 May 1;104(1):157-164. doi: 10.1016/j.ijrobp.2018.12.042. Epub 2018 Dec 31.
Recent Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology guidelines recommend that the dose to 90% (D90) of the high-risk clinical target volume (HRCTV) in cervical cancer be at least 85 Gy, with higher doses for poor response to radiation therapy.
A retrospective review of brachytherapy delivered at a single institution was evaluated for dosimetry and outcomes. Significance of tumor parameters on local control was evaluated with Kaplan-Meier and univariable and multivariable Cox regression analysis. Correlations were determined with a linear regression model.
A total of 239 women underwent high-dose-rate brachytherapy for cervical cancer between 2007 and 2018 with evaluable dosimetry. Median follow-up was 28.6 months. The median prescribed dose was 27.5 Gy in 5 fractions, with a median HRCTV D90 of 83.9 Gy (range, 81.9-85.7 Gy), HRCTV volume of 31 cm (range, 14.9-121.9 cm), and treatment time of 51 days (range, 36-83 days). Local control for the entire cohort at 5 years was 90.8%. Local control was worse with adenocarcinomas, HRCTV >40 cm at brachytherapy, requirement for a higher brachytherapy dose, and treatment >51 days. On multivariable analysis, local control was worse with adenocarcinoma (hazard ratio, 4.141; 95% confidence interval, 1.498-11.444; P = .006) and HRCTV >40 cm (hazard ratio, 3.640; 95% confidence interval, 1.316-10.069; P = .013). HRCTV EQD2 D90 > 85 Gy did not statistically improve outcomes for any subset. The 2-year progression-free survival for HRCTV >40 cm was 66.2% versus 84.1% if ≤40 cm (P < .001). Overall survival was predicted by HRCTV and overall treatment time in multivariable analysis. For women with HRCTV ≤40 cm, overall survival at 2 years was 90.4% versus 68.5% if >40 cm (P < .001).
Local control was excellent with magnetic resonance imaging-based planning in the entire cohort of patients. A poor response to external beam radiation (larger HRCTV) and adenocarcinoma histology predicted for worse local control despite association with higher brachytherapy prescription. Women with these risk factors face higher rates of extrapelvic progression and poorer overall survival.
最近的欧洲放射治疗和肿瘤学学会（Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology）指南建议宫颈癌高危临床靶区（HRCTV）的 90%（D90）剂量至少为 85Gy，对于放疗反应不佳的患者应给予更高剂量。
对单机构实施的近距离放射治疗进行了回顾性审查，以评估剂量学和治疗结果。采用 Kaplan-Meier 法和单变量及多变量 Cox 回归分析评估肿瘤参数对局部控制的意义。采用线性回归模型确定相关性。
2007 年至 2018 年间，共有 239 名宫颈癌患者接受了高剂量率近距离放射治疗，可评估剂量学。中位随访时间为 28.6 个月。中位处方剂量为 27.5Gy，共 5 次，HRCTV D90 中位数为 83.9Gy（范围 81.9-85.7Gy），HRCTV 体积中位数为 31cm³（范围 14.9-121.9cm³），治疗时间中位数为 51 天（范围 36-83 天）。全组患者 5 年局部控制率为 90.8%。局部控制较差的因素包括腺癌、近距离放射治疗时 HRCTV ＞40cm³、需要更高的近距离放射治疗剂量和治疗时间＞51 天。多变量分析显示，局部控制较差与腺癌（风险比，4.141；95%置信区间，1.498-11.444；P=0.006）和 HRCTV ＞40cm³（风险比，3.640；95%置信区间，1.316-10.069；P=0.013）相关。HRCTV 等效生物剂量 2 （equivalent dose in 2 Gy，EQD2）D90 ＞85Gy 并未显著改善任何亚组的治疗结果。HRCTV ＞40cm³患者的 2 年无进展生存率为 66.2%，而 HRCTV ≤40cm³患者为 84.1%（P＜0.001）。多变量分析预测了总生存与 HRCTV 和总治疗时间相关。对于 HRCTV≤40cm³的患者，2 年总生存率为 90.4%，而 HRCTV＞40cm³的患者为 68.5%（P＜0.001）。
基于磁共振成像的计划在整个患者队列中实现了出色的局部控制。尽管与更高的近距离放射治疗处方相关，但对外照射放疗的反应不佳（更大的 HRCTV）和腺癌组织学预测会导致局部控制更差。具有这些危险因素的女性面临更高的盆外进展率和更差的总体生存率。
