局部区域加热期间的在线自适应热疗治疗计划，以抑制限制治疗的热点。

Online Adaptive Hyperthermia Treatment Planning During Locoregional Heating to Suppress Treatment-Limiting Hot Spots.

作者信息

Kok H Petra, Korshuize-van Straten Linda, Bakker Akke, de Kroon-Oldenhof Rianne, Geijsen Elisabeth D, Stalpers Lukas J A, Crezee Johannes

机构信息

Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.

出版信息

Int J Radiat Oncol Biol Phys. 2017 Nov 15;99(4):1039-1047. doi: 10.1016/j.ijrobp.2017.07.011. Epub 2017 Jul 14.

DOI:10.1016/j.ijrobp.2017.07.011

PMID:28870786

Abstract

BACKGROUND

Adequate tumor temperatures during hyperthermia are essential for good clinical response, but excessive heating of normal tissue should be avoided. This makes locoregional heating using phased array systems technically challenging. Online application of hyperthermia treatment planning could help to improve the heating quality. The aim of this study was to evaluate the clinical benefit of online treatment planning during treatment of pelvic tumors heated with the AMC-8 locoregional hyperthermia system.

METHODS

For online adaptive hyperthermia treatment planning, a graphical user interface was developed. Electric fields were calculated in a preprocessing step using our in-house-developed finite-difference-based treatment planning system. This allows instant calculation of the temperature distribution for user-selected phase-amplitude settings during treatment and projection onto the patient's computed tomographic scan for online visualization. Online treatment planning was used for 14 treatment sessions in 8 patients to reduce the patients' reports of hot spots while maintaining the same level of tumor heating. The predicted decrease in hot spot temperature should be at least 0.5°C, and the tumor temperature should decrease less than 0.2°C. These predictions were compared with clinical data: patient feedback about the hot spot and temperature measurements in the tumor region.

RESULTS

In total, 17 hot spot reports occurred during the 14 sessions, and the alternative settings predicted the hot spot temperature to decrease by at least 0.5°C, which was confirmed by the disappearance of all 17 hot spot reports. At the same time, the average tumor temperature was predicted to change on average -0.01°C (range, -0.19°C to 0.34°C). The measured tumor temperature change was on average only -0.02°C (range, -0.26°C to 0.31°C). In only 2 cases the temperature decrease was slightly larger than 0.2°C, but at most it was 0.26°C.

CONCLUSIONS

Online application of hyperthermia treatment planning is reliable and very useful to reduce hot spots without affecting tumor temperatures.

摘要

背景

热疗期间达到足够的肿瘤温度对于良好的临床反应至关重要，但应避免正常组织过度受热。这使得使用相控阵系统进行局部加热在技术上具有挑战性。热疗治疗计划的在线应用有助于提高加热质量。本研究的目的是评估在使用AMC - 8局部热疗系统加热盆腔肿瘤的治疗过程中在线治疗计划的临床益处。

方法

为了进行在线自适应热疗治疗计划，开发了一个图形用户界面。在预处理步骤中，使用我们自主研发的基于有限差分的治疗计划系统计算电场。这允许在治疗期间即时计算用户选择的相位 - 幅度设置下的温度分布，并投影到患者的计算机断层扫描上以进行在线可视化。在线治疗计划用于8名患者的14个治疗疗程，以减少患者报告的热点，同时保持相同水平的肿瘤加热。预测热点温度降低应至少0.5°C，肿瘤温度降低应小于0.2°C。将这些预测与临床数据进行比较：患者关于热点的反馈以及肿瘤区域的温度测量。

结果

在14个疗程中共出现17次热点报告，替代设置预测热点温度降低至少0.5°C，所有17次热点报告均消失证实了这一点。同时，预测平均肿瘤温度平均变化 -0.01°C（范围为 -0.19°C至0.34°C）。测得的肿瘤温度变化平均仅为 -0.02°C（范围为 -0.26°C至0.31°C）。仅在2例中温度降低略大于0.2°C，但最多为0.26°C。