Abstract：
Objective.High-dose-rate (HDR) brachytherapy lacks routinely available treatment verification methods. Real-time tracking of the radiation source during HDR brachytherapy can enhance treatment verification capabilities. Recent developments in source tracking allow for measurement of dwell times and source positions with high accuracy. However, more clinically relevant information, such as dose discrepancies, is still needed. To address this, a real-time dose calculation implementation was developed to provide more relevant information from source tracking data. A proof-of-principle of the developed tool was shown using source tracking data obtained from a 3D-printed anthropomorphic phantom.Approach.Software was developed to calculate dose-volume-histograms (DVH) and clinical dose metrics from experimental HDR prostate treatment source tracking data, measured in a realistic pelvic phantom. Uncertainty estimation was performed using repeat measurements to assess the inherent dose measuring uncertainty of thein vivodosimetry (IVD) system. Using a novel approach, the measurement uncertainty can be incorporated in the dose calculation, and used for evaluation of cumulative dose and clinical dose-volume metrics after every dwell position, enabling real-time treatment verification.Main results.The dose calculated from source tracking measurements aligned with the generated uncertainty bands, validating the approach. Simulated shifts of 3 mm in 5/17 needles in a single plan caused DVH deviations beyond the uncertainty bands, indicating errors occurred during treatment. Clinical dose-volume metrics could be monitored in a time-resolved approach, enabling early detection of treatment plan deviations and prediction of their impact on the final dose that will be delivered in real-time.Significance.Integrating dose calculation with source tracking enhances the clinical relevance of IVD methods. Phantom measurements show that the developed tool aids in tracking treatment progress, detecting errors in real-time and post-treatment evaluation. In addition, it could be used to define patient-specific action limits and error thresholds, while taking the uncertainty of the measurement system into consideration.
摘要：
目的：高剂量率（HDR）近距离放射治疗缺乏常规可用的治疗验证方法。HDR近距离放射治疗期间辐射源的实时跟踪可以增强治疗验证能力。源跟踪的最新发展允许高精度地测量停留时间和源位置。然而,更多临床相关信息，如剂量差异，仍然需要。为了解决这个问题，开发了实时剂量计算实现方案,以从源跟踪数据中提供更多相关信息.使用从3D打印的拟人化体模获得的源跟踪数据显示了所开发的工具的原理证明。＆＃xD;方法：开发软件来计算剂量-体积-直方图（DVH）和临床剂量指标从实验HDR前列腺治疗源跟踪数据，在现实的骨盆幻影中测量。使用重复测量进行不确定性估计，以评估体内剂量测定（IVD）系统的固有剂量测量不确定性。使用一种新颖的方法，测量不确定度可以纳入剂量计算，并用于评估每个停留位置后的累积剂量和临床剂量体积指标，实现实时治疗验证。＆＃xD;主要结果：根据源跟踪测量值计算的剂量与生成的不确定性带一致，验证方法。单个计划中5/17针中3mm的模拟位移导致DVH偏差超出不确定范围，指示治疗期间发生的错误。临床剂量-体积指标可以通过时间分辨方法进行监测，能够早期检测治疗计划偏差并预测其对将实时递送的最终剂量的影响。＆＃xD;意义：将剂量计算与来源跟踪相结合可增强IVD方法的临床相关性。幻影测量表明，开发的工具有助于跟踪治疗进展，在实时和治疗后评估中检测错误。此外,它可用于定义患者特定的动作限制和错误阈值，同时考虑测量系统的不确定度。
