Introduction
To report the impact of dose and tumor volume metrics at brachytherapy on outcomes for locally advanced cervical cancer treated with tandem and ovoids intracavitary/interstitial brachytherapy.

Material and methods
FIGO stage IB1-IIIB locally advanced cervical cancer treated with intracavitary/interstitial brachytherapy via a tandem and ovoids hybrid applicator were analyzed. Median high-risk clinical target volume (HR-CTV), rate of tumor volume reduction, EQD2 D90, organ at risk doses, and outcomes were recorded. Univariable and multivariable Cox regression was applied for survival analysis, and logistic regression was used for toxicity analysis.

Results
Seventy-one patients were identified. Median follow-up was 24.9 months, with a 2-year local control of 83.6%, loco-regional control of 72.0%, and overall survival of 88.6%. Median HR-CTV D90 was 87.4 Gy (IQR = 85.7-90.2). Median HR-CTV D90 > 90 Gy10 showed a trend toward improved local control (LC) (p = 0.19). Median HR-CTV was 37.9 cm3, and median V100 was 86.5%. A median HR-CTV of ≥ 40 cm3 demonstrated worse loco-regional control (LRC) (p = 0.018) and progression-free survival (p = 0.021). Two-year LC and LRC for stage IIB patients with a median HR-CTV < 40 cm3 were significantly improved as compared to ≥ 40 cm3 at 100% and 71.8%, respectively (p = 0.019) and 100% and 56.5%, respectively (p = 0.001). However, this trend was not statistically significant for stage IIIB patients. Higher percent per day reduction in HR-CTV during brachytherapy showed improved LRC (p = 0.045). Four percent of patients experienced acute grade 3 genitourinary toxicity, 1% late grade 3 genitourinary and 1% late grade 3 gastrointestinal toxicity.

Conclusions
Tandem and ovoids intracavitary/interstitial brachytherapy provides satisfactory outcomes with modest toxicity. Higher HR-CTV D90 coverage demonstrated a trend toward improved tumor control. Tumor volume based on median HR-CTV ≥ 40 cm3 at brachytherapy was prognostic for poor outcomes, even within initial FIGO stage groups warranting caution.



中文翻译：

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混合串联和卵形近距离放射治疗局部晚期宫颈癌：剂量和肿瘤体积指标对结果的影响

简介
报告近距离放射治疗中剂量和肿瘤体积指标对采用串联和卵形腔内/间质近距离放射治疗的局部晚期宫颈癌结果的影响。

材料和方法
对FIGO IB1-IIIB期局部晚期宫颈癌通过串联和卵形混合涂药器进行腔内/间质近距离放射治疗进行了分析。记录中位高危临床靶区 (HR-CTV)、肿瘤体积缩小率、EQD2 D90、风险器官剂量和结果。生存分析采用单变量和多变量Cox回归，毒性分析采用Logistic回归。

结果
确定了 71 名患者。中位随访时间为 24.9 个月，2 年局部控制率为 83.6%，局部区域控制率为 72.0%，总生存率为 88.6%。中位 HR-CTV D90 为 87.4 Gy (IQR = 85.7-90.2)。中位 HR-CTV D90 > 90 Gy10 显示出改善局部控制 (LC) 的趋势 (p = 0.19)。中位 HR-CTV 为 37.9 cm3，中位 V100 为 86.5%。≥ 40 cm3 的中位 HR-CTV 显示更差的局部区域控制 (LRC) (p = 0.018) 和无进展生存期 (p = 0.021)。与≥40 cm3 相比，中位 HR-CTV < 40 cm3 的 IIB 期患者的两年 LC 和 LRC 分别显着改善了 100% 和 71.8%（p = 0.019）和 100% 和 56.5%（ p = 0.001)。然而，这种趋势在 IIIB 期患者中没有统计学意义。近距离放射治疗期间 HR-CTV 每天降低的百分比较高表明 LRC 有所改善（p = 0.045）。4% 的患者出现急性 3 级泌尿生殖系统毒性，1% 的晚期 3 级泌尿生殖系统毒性和 1% 的晚期 3 级胃肠道毒性。

结论
串联和卵形腔内/间质近距离放射治疗提供了令人满意的结果和适度的毒性。更高的 HR-CTV D90 覆盖率显示出改善肿瘤控制的趋势。基于近距离放射治疗中 HR-CTV ≥ 40 cm3 的肿瘤体积可预测不良预后，即使在最初的FIGO 阶段组中也需要谨慎。