Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Rotterdam, the Netherlands.
Department of Electrical Engineering, Chalmers University of Technology, Gothenburg, Sweden.
Int J Hyperthermia. 2023;40(1):2272578. doi: 10.1080/02656736.2023.2272578. Epub 2023 Oct 25.
This study aimed to assess the quality of the lucite cone applicator (LCA), the standard applicator for superficial hyperthermia at the Erasmus MC Cancer Institute, using the most recent quality assurance guidelines, thus verifying their feasibility.
The assessment was conducted on each of the six LCAs available for clinical treatments. The temperature distribution was evaluated using an infrared camera across different layers of a fat-muscle mimicking phantom. The maximum temperature increase, thermal effective penetration depth (TEPD), and thermal effective field size (TEFS) were used as quality metrics. The experimental results were validated through comparison with simulated results, using a canonical phantom model and a realistic phantom model segmented from CT imaging.
A maximum temperature increase above 6 °C at 2 cm depth in the fat-muscle phantom for all the experiments was found. A mean negative difference between simulated and experimental data was of 1.3 °C when using the canonical phantom model. This value decreased to a mean negative difference of 0.4 °C when using the realistic model. Simulated and measured TEPD showed good agreement for both scenarios, while discrepancies were present for TEFS.
The LCAs passed all QA guidelines requirements for superficial hyperthermia delivery when used singularly or in an array configuration. A further characterization of parameters such as antenna efficiency and heat transfer coefficients would be beneficial for translating experimental results to simulated values. Implementing the QA guidelines was time-consuming and demanding, requiring careful preparation and correct setup of antenna elements.
本研究旨在评估 Erasmus MC 癌症研究所浅层热疗标准施源器——聚甲基丙烯酸甲酯（PMMA）圆锥施源器的质量，使用最新的质量保证指南来验证其可行性。
对临床治疗中可用的 6 个 PMMA 圆锥施源器进行评估。通过在脂肪-肌肉模拟体模的不同层使用红外摄像机来评估温度分布。使用最大温升、热有效穿透深度（TEPD）和热有效场尺寸（TEFS）作为质量指标。通过使用标准体模模型和从 CT 成像中分割的真实体模模型进行模拟结果验证实验结果。
在所有实验中，脂肪-肌肉体模中 2cm 深处的最大温升均超过 6°C。当使用标准体模模型时，模拟数据与实验数据之间的平均差值为 1.3°C。当使用真实体模模型时，该值降低至平均差值 0.4°C。两种情况下，模拟和测量的 TEPD 均具有很好的一致性，而 TEFS 存在差异。
当单独使用或在阵列配置中使用时，PMMA 圆锥施源器均通过了浅层热疗输送的所有 QA 指南要求。进一步表征天线效率和热传递系数等参数将有助于将实验结果转化为模拟值。实施 QA 指南既耗时又费力，需要仔细准备和正确设置天线元件。
