Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center, Dr. Molewaterplein 40, 3015 GD Rotterdam, the Netherlands.
Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center, Dr. Molewaterplein 40, 3015 GD Rotterdam, the Netherlands; Department of Medical Physics & Informatics, HollandPTC, Delft, the Netherlands.
Radiother Oncol. 2024 Nov;200:110501. doi: 10.1016/j.radonc.2024.110501. Epub 2024 Aug 25.
Electromagnetic Tracking (EMT) technology has been integrated in a prototype high-dose-rate brachytherapy (HDR-BT) afterloading device. Its potential for dwell position (DP) monitoring has earlier been demonstrated in prostate phantoms. However, its performance for prostate BT in the clinical setting remains to be assessed.
Assess the reliability and value of EMT measurements in transrectal ultrasound-based (TRUS-based) and computed tomography-based (CT-based) prostate HDR-BT.
EMT measurements were conducted on 20 patients undergoing dual-fraction prostate HDR-BT monotherapy. In each treatment fraction an individual TRUS-based or CT-based treatment plan was generated. The measurements were compared to DPs of manually reconstructed needles in those TRUS-based or CT-based treatment plans. An internal reference sensor was also placed in one needle to assess internal movement levels and its potential for movement correction.
For TRUS-based treatments, median Euclidean distances (ED) of 1.00 mm were observed between EMT measurements and manual DP determination. Reference sensor movement was minimal at a median of 0.18 mm. For DPs measured in the CT-room and treatment room, median EDs of 1.60 mm and 2.24 mm compared to CT-based DP determination respectively were observed, indicating the system's ability to detect changes in implant geometry over time and after patient repositioning. Median reference sensor movement of 0.97 mm was observed. Implementing reference sensor-based movement correction led to a significant but small decrease in ED for CT-based treatments.
EMT is suitable for TRUS-based prostate HDR-BT quality assurance and error detection. While EMT can identify changes in implant geometry in CT-based prostate HDR-BT treatments, it showed lower accuracy in this setting.
电磁跟踪（EMT）技术已集成在原型高剂量率近距离治疗（HDR-BT）后装设备中。其在前列腺模型中用于驻留位置（DP）监测的潜力已得到早期证明。然而，其在临床环境中用于前列腺 BT 的性能仍有待评估。
评估 EMT 测量在经直肠超声（TRUS）和计算机断层扫描（CT）基于的前列腺 HDR-BT 中的可靠性和价值。
对 20 名接受双剂量分割前列腺 HDR-BT 单一疗法的患者进行 EMT 测量。在每个治疗剂量中，生成了一个单独的基于 TRUS 或 CT 的治疗计划。将测量结果与这些基于 TRUS 或 CT 的治疗计划中手动重建针的 DP 进行比较。还在一根针中放置了一个内部参考传感器，以评估内部运动水平及其用于运动校正的潜力。
对于基于 TRUS 的治疗，EMT 测量值与手动 DP 确定值之间的中位数欧式距离（ED）为 1.00mm。参考传感器的运动最小，中位数为 0.18mm。对于在 CT 室和治疗室中测量的 DP，与 CT 基于 DP 确定值相比，中位数 ED 分别为 1.60mm 和 2.24mm，表明系统能够检测到随时间推移和患者重新定位后植入物几何形状的变化。观察到参考传感器的中位运动为 0.97mm。实施基于参考传感器的运动校正导致 CT 基于治疗的 ED 显著但略有降低。
EMT 适用于基于 TRUS 的前列腺 HDR-BT 质量保证和误差检测。虽然 EMT 可以识别 CT 基于前列腺 HDR-BT 治疗中植入物几何形状的变化，但在这种情况下准确性较低。
