van der Ree Martijn H, Cuculich Phillip S, van Herk Marcel, Hugo Geoffrey D, Balt Jippe C, Bates Matthew, Ho Gordon, Pruvot Etienne, Herrera-Siklody Claudia, Hoeksema Wiert F, Lee Justin, Lloyd Michael S, Kemme Michiel J B, Sacher Frederic, Tixier Romain, Verhoeff Joost J C, Balgobind Brian V, Robinson Clifford G, Rasch Coen R N, Postema Pieter G
Department of Cardiology, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands.
Department of Cardiology, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, Netherlands.
Front Cardiovasc Med. 2023 Sep 20;10:1267800. doi: 10.3389/fcvm.2023.1267800. eCollection 2023.
Stereotactic arrhythmia radioablation (STAR) is a potential new therapy for patients with refractory ventricular tachycardia (VT). The arrhythmogenic substrate (target) is synthesized from clinical and electro-anatomical information. This study was designed to evaluate the baseline interobserver variability in target delineation for STAR.
Delineation software designed for research purposes was used. The study was split into three phases. Firstly, electrophysiologists delineated a well-defined structure in three patients (spinal canal). Secondly, observers delineated the VT-target in three patients based on case descriptions. To evaluate baseline performance, a basic workflow approach was used, no advanced techniques were allowed. Thirdly, observers delineated three predefined segments from the 17-segment model. Interobserver variability was evaluated by assessing volumes, variation in distance to the median volume expressed by the root-mean-square of the standard deviation (RMS-SD) over the target volume, and the Dice-coefficient.
Ten electrophysiologists completed the study. For the first phase interobserver variability was low as indicated by low variation in distance to the median volume (RMS-SD range: 0.02-0.02 cm) and high Dice-coefficients (mean: 0.97 ± 0.01). In the second phase distance to the median volume was large (RMS-SD range: 0.52-1.02 cm) and the Dice-coefficients low (mean: 0.40 ± 0.15). In the third phase, similar results were observed (RMS-SD range: 0.51-1.55 cm, Dice-coefficient mean: 0.31 ± 0.21).
Interobserver variability is high for manual delineation of the VT-target and ventricular segments. This evaluation of the baseline observer variation shows that there is a need for methods and tools to improve variability and allows for future comparison of interventions aiming to reduce observer variation, for STAR but possibly also for catheter ablation.
立体定向心律失常射频消融术（STAR）是一种针对难治性室性心动过速（VT）患者的潜在新疗法。致心律失常基质（靶点）由临床和电解剖信息合成。本研究旨在评估STAR靶点勾画中观察者间的基线变异性。
使用专为研究目的设计的勾画软件。该研究分为三个阶段。首先，电生理学家在三名患者（椎管）中勾画出一个明确的结构。其次，观察者根据病例描述在三名患者中勾画出VT靶点。为评估基线表现，采用基本工作流程方法，不允许使用先进技术。第三，观察者从17段模型中勾画出三个预定义节段。通过评估体积、目标体积上标准差的均方根（RMS-SD）表示的与中位数体积的距离变化以及Dice系数来评估观察者间变异性。
十名电生理学家完成了该研究。对于第一阶段，观察者间变异性较低，表现为与中位数体积的距离变化较小（RMS-SD范围：0.02 - 0.02 cm）且Dice系数较高（平均值：0.97±0.01）。在第二阶段，与中位数体积的距离较大（RMS-SD范围：0.52 - 1.02 cm）且Dice系数较低（平均值：0.40±0.15）。在第三阶段，观察到类似结果（RMS-SD范围：0.51 - 1.55 cm，Dice系数平均值：0.31±0.21）。
手动勾画VT靶点和心室节段时观察者间变异性较高。对基线观察者变异的评估表明，需要方法和工具来改善变异性，并允许未来对旨在减少观察者变异的干预措施进行比较，不仅适用于STAR，也可能适用于导管消融术。
