Department of Radiotherapy, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Shuaifuyuan Wangfujing Dongcheng District, Beijing, 100730, China.
Chindex Medical Limited, Shanghai, 201103, China.
BMC Cancer. 2024 Aug 22;24(1):1041. doi: 10.1186/s12885-024-12814-5.
Ir192 vaginal brachytherapy (IBT) is commonly used for patients with postoperative endometrial cancer (EC). We devised a novel multichannel vaginal applicator that could be equipped with an electronic brachytherapy (EBT) device. We aimed to explore the differences in physical parameters between the EBT and IBT.
This retrospective study included 20 EC patients who received adjuvant IBT from March 1, 2023, to May 1, 2023. Multichannel vaginal cylinders were used, and three-dimensional plans were generated. We designed an electronic multichannel vaginal applicator model and simulated a three-dimensional EBT plan. In order to ensure comparability, D90 of the CTV for the EBT plan was normalized to be equivalent to that of the IBT plan for the same patient.
Twenty EBT plans were compared with 20 IBT plans. Results showed, the mean D90 value of clinical target volume (CTV) was 536.1 cGy for both treatment plans. For the mean dose of CTV, the EBT was significantly greater (738.3 vs. 684.3 cGy, p = 0.000). There was no significant difference in CTV coverage between the EBT and IBT plans. For high-dose areas (V200% and V150%), the EBTs were significantly greater. There were no significant differences in the maximum doses to the vaginal mucosa between the EBT and IBT, whether at the apex or in the middle segment. For the bladder and rectum, both the low-dose area and high-dose area were significantly lower in the EBT plans. For the conformity index, there was no significant difference between the EBT and IBT plans. For the dose homogeneity index, the EBT value was lower.
In conclusion, under the premise of a three-dimensional brachytherapy plan, for patients receiving multichannel vaginal applicator brachytherapy, compared with IBT, EBT could reduce the dose to the surrounding organs at risk while maintaining the dose in the target area.
Ir192 阴道近距离放疗（IBT）常用于术后子宫内膜癌（EC）患者。我们设计了一种新型多通道阴道施源器，可配备电子近距离放疗（EBT）设备。我们旨在探讨 EBT 和 IBT 之间物理参数的差异。
本回顾性研究纳入 2023 年 3 月 1 日至 5 月 1 日接受辅助 IBT 的 20 例 EC 患者。使用多通道阴道圆柱，生成三维计划。我们设计了一种电子多通道阴道施源器模型，并模拟了三维 EBT 计划。为了确保可比性，EBT 计划的 CTV 的 D90 值被归一化为与同一患者的 IBT 计划相同。
比较了 20 例 EBT 计划和 20 例 IBT 计划。结果显示，CTV 的平均 D90 值为两种治疗方案的 536.1 cGy。对于 CTV 的平均剂量，EBT 明显更高（738.3 比 684.3 cGy，p=0.000）。EBT 和 IBT 计划的 CTV 覆盖率无显著差异。对于高剂量区（V200%和 V150%），EBT 明显更高。EBT 和 IBT 计划对阴道黏膜的最大剂量无显著差异，无论是在顶端还是中段。对于膀胱和直肠，EBT 计划的低剂量区和高剂量区均显著降低。对于适形指数，EBT 和 IBT 计划无显著差异。对于剂量均匀性指数，EBT 值较低。
总之，在三维近距离放疗计划的前提下，对于接受多通道阴道施源器近距离放疗的患者，与 IBT 相比，EBT 可以在保持靶区剂量的同时降低周围危及器官的剂量。
