PURPOSE

This study aimed to assess the impact of dose rates due to natural decay of Iridium-192 sources and the risk factors of clinical outcomes for cervical cancer patients treated with high-dose-rate (HDR) brachytherapy.

METHODS AND MATERIALS

Four ninety-four patients were divided into relatively-high-radioactive (rHR), relatively-medium-radioactive (rMR), and relatively-low-radioactive (rLR) groups for retrospective treatment response comparison. The short-term outcomes were evaluated using the 1-month /3-month follow-up results based on RECIST 1.1. Local recurrence-free survival (LRFS) and metastatic recurrence-free survival (MRFS) were selected as long-term outcomes. A class of transformation models with adaptive lasso was applied to assess the risk factors of long-term outcomes.

RESULTS

No significant difference was identified in short- or long-term outcomes of different radioactive groups. Subgroup analyses demonstrated similar findings. In multivariate factor analysis, advanced stage was significantly associated with higher risk of local recurrence and metastatic recurrence (HR = 1.66, 95%confidence interval [CI] = 1.14–2.43, p = 0.008; HR = 1.57, 95%CI = 1.23–2.00, p < 0.001). Significant associations were observed between local recurrence and pathology, and between metastatic recurrence and pre-treatment serum indices, respectively (HR = 8.62, 95%CI = 2.28–32.60, p = 0.002; HR = 1.98, 95%CI=1.20–2.26, p = 0.008).

CONCLUSIONS

Overall, there was no significant difference in long- or short-term efficacy of the HDR brachytherapy among the groups with different levels of activity of radiation sources. Stage, pathology, and pretreatment serum indices were crucial factors that affected the long-term outcomes.

中文翻译：

---

不同放射源活动的高剂量率近距离放射治疗对宫颈癌患者的疗效及长期结果的危险因素：一项为期 6 年的回顾性研究

目的

本研究旨在评估铱 192 源自然衰减造成的剂量率的影响以及接受高剂量率 (HDR) 近距离放射治疗的宫颈癌患者临床结果的危险因素。

方法和材料

将 4 94 名患者分为相对高放射性（rHR）、相对中放射性（rMR）和相对低放射性（rLR）组进行回顾性治疗反应比较。根据RECIST 1.1，使用1个月/3个月的随访结果评估短期结局。选择局部无复发生存期（LRFS）和转移无复发生存期（MRFS）作为长期结果。应用一类具有自适应套索的转换模型来评估长期结果的风险因素。

结果

不同放射性组的短期或长期结果没有显着差异。亚组分析显示了类似的结果。在多变量因素分析中，晚期分期与局部复发和转移复发的较高风险显着相关（HR = 1.66，95%置信区间[CI] = 1.14–2.43，p  = 0.008；HR = 1.57，95%CI = 1.23– 2.00，p < 0.001）。局部复发与病理学之间以及转移性复发与治疗前血清指数之间分别观察到显着相关性（HR = 8.62，95% CI = 2.28–32.60，p  = 0.002；HR = 1.98，95% CI = 1.20–2.26） ，p  = 0.008）。

结论

总体而言，不同放射源活动水平的组中 HDR 近距离放射治疗的长期或短期疗效没有显着差异。分期、病理学和治疗前血清指标是影响长期结果的关键因素。