Kok H Petra, Groen Jort, Bakker Akke, Crezee Johannes
Department of Radiation Oncology, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.
Cancers (Basel). 2020 Mar 11;12(3):656. doi: 10.3390/cancers12030656.
This paper describes a method to reconstruct bendable superficial hyperthermia applicators for routine clinical patient-specific treatment planning. The reconstruction uses a CT scan with a flexible silicone dummy applicator positioned on the patient. The curvature was approximated by two second-degree polynomial functions. A realistic treatment series was mimicked using a standard Alderson radiation therapy phantom and a treatment planning model was reconstructed from a CT scan. The variation among treatment curvatures was compared to the modelled curvature. The mathematical approximation of the applicator curvature was validated for this phantom experiment, as well as for clinical treatments. The average maximum variation among the successive mimicked sessions was 3.67 ± 0.69 mm (range 2.98-4.60mm). The maximum deviation between the treatment curvature and the modelled curvature was 4.35 mm. Comparing the treatment and approximated curvature yielded a maximum deviation between 2.98 mm and 4.12 mm. For clinical treatments the maximum deviation of the treatment and approximated curvature varied between 0.48 mm and 1.98 mm. These results allow adequate reconstruction of bendable hyperthermia applicators for treatment planning, which can further improve treatment quality, for example by optimizing the water bolus temperature for patient-specific tumor depths. Predictive parameters for hyperthermia treatment outcome can easily be evaluated and compared for various input parameters.
本文描述了一种重建可弯曲浅表热疗施源器的方法，用于常规临床患者特异性治疗计划。重建过程使用CT扫描，将柔性硅胶模拟施源器放置在患者身上。曲率由两个二次多项式函数近似表示。使用标准的Alderson放射治疗体模模拟了一个实际的治疗系列，并从CT扫描重建了一个治疗计划模型。将治疗曲率的变化与模拟曲率进行比较。针对该体模实验以及临床治疗，验证了施源器曲率的数学近似。连续模拟疗程之间的平均最大变化为3.67±0.69毫米（范围2.98 - 4.60毫米）。治疗曲率与模拟曲率之间的最大偏差为4.35毫米。比较治疗曲率和近似曲率得出的最大偏差在2.98毫米至4.12毫米之间。对于临床治疗，治疗曲率与近似曲率的最大偏差在0.48毫米至1.98毫米之间变化。这些结果允许对可弯曲热疗施源器进行充分重建以用于治疗计划，这可以进一步提高治疗质量，例如通过针对患者特异性肿瘤深度优化水垫温度。热疗治疗结果的预测参数可以很容易地针对各种输入参数进行评估和比较。
