Koga Sebastian F, Hodges Wesley B, Adamyan Hayk, Hayes Tim, Fecci Peter E, Tsvankin Vadim, Pradilla Gustavo, Hoang Kimberly B, Lee Ian Y, Sankey Eric W, Codd Patrick J, Huie David, Zacharia Brad E, Verma Ragini, Baboyan Vatche G
Franciscan Missionaries of Our Lady Health System, Baton Rouge, LA, United States.
Synaptive Medical Inc., Toronto, ON, Canada.
Front Neurol. 2024 Jan 8;14:1322815. doi: 10.3389/fneur.2023.1322815. eCollection 2023.
Peritumoral edema alters diffusion anisotropy, resulting in false negatives in tractography reconstructions negatively impacting surgical decision-making. With supratotal resections tied to survival benefit in glioma patients, advanced diffusion modeling is critical to visualize fibers within the peritumoral zone to prevent eloquent fiber transection thereafter. A preoperative assessment paradigm is therefore warranted to systematically evaluate multi-subject tractograms along clinically meaningful parameters. We propose a novel noninvasive surgically-focused survey to evaluate the benefits of a tractography algorithm for preoperative planning, subsequently applied to Synaptive Medical's free-water correction algorithm developed for clinically feasible single-shell DTI data.
Ten neurosurgeons participated in the study and were presented with patient datasets containing histological lesions of varying degrees of edema. They were asked to compare standard (uncorrected) tractography reconstructions overlaid onto anatomical images with enhanced (corrected) reconstructions. The raters assessed the datasets in terms of overall data quality, tract alteration patterns, and the impact of the correction on lesion definition, brain-tumor interface, and optimal surgical pathway. Inter-rater reliability coefficients were calculated, and statistical comparisons were made.
Standard tractography was perceived as problematic in areas proximal to the lesion, presenting with significant tract reduction that challenged assessment of the brain-tumor interface and of tract infiltration. With correction applied, significant reduction in false negatives were reported along with additional insight into tract infiltration. Significant positive correlations were shown between favorable responses to the correction algorithm and the lesion-to-edema ratio, such that the correction offered further clarification in increasingly edematous and malignant lesions. Lastly, the correction was perceived to introduce false tracts in CSF spaces and - to a lesser degree - the grey-white matter interface, highlighting the need for noise mitigation. As a result, the algorithm was modified by free-water-parameterizing the tractography dataset and introducing a novel adaptive thresholding tool for customizable correction guided by the surgeon's discretion.
Here we translate surgeon insights into a clinically deployable software implementation capable of recovering peritumoral tracts in edematous zones while mitigating artifacts through the introduction of a novel and adaptive case-specific correction tool. Together, these advances maximize tractography's clinical potential to personalize surgical decisions when faced with complex pathologies.
肿瘤周围水肿会改变扩散各向异性，导致纤维束成像重建出现假阴性结果，对手术决策产生负面影响。由于全切除与胶质瘤患者的生存获益相关，先进的扩散模型对于可视化肿瘤周围区域的纤维以防止术后切断明确的纤维至关重要。因此，需要一种术前评估范式来根据临床有意义的参数系统地评估多主体纤维束成像。我们提出了一种新颖的以手术为重点的非侵入性调查，以评估一种纤维束成像算法对术前规划的益处，随后将其应用于为临床可行的单壳扩散张量成像（DTI）数据开发的Synaptive Medical的自由水校正算法。
十名神经外科医生参与了该研究，并被展示了包含不同程度水肿组织学病变的患者数据集。他们被要求将叠加在解剖图像上的标准（未校正）纤维束成像重建与增强（校正）重建进行比较。评估者从整体数据质量、纤维束改变模式以及校正对病变定义、脑肿瘤界面和最佳手术路径的影响等方面对数据集进行评估。计算了评估者间可靠性系数，并进行了统计比较。
标准纤维束成像在病变近端区域被认为存在问题，出现明显的纤维束减少，这对脑肿瘤界面和纤维束浸润的评估提出了挑战。应用校正后，报告显示假阴性显著减少，同时对纤维束浸润有了更多了解。对校正算法的良好反应与病变与水肿比值之间显示出显著的正相关，因此校正为水肿和恶性程度日益增加的病变提供了进一步的清晰度。最后，可以察觉到校正会在脑脊液空间以及在较小程度上在灰白质界面引入假纤维束，这突出了减轻噪声的必要性。结果，通过对纤维束成像数据集进行自由水参数化并引入一种新颖的自适应阈值工具以根据外科医生的判断进行可定制校正，对该算法进行了修改。
在此，我们将外科医生的见解转化为一种可临床部署的软件实施方案，该方案能够在水肿区域恢复肿瘤周围纤维束，同时通过引入一种新颖的、针对具体病例的自适应校正工具来减轻伪影。总之，这些进展最大限度地发挥了纤维束成像在面对复杂病理情况时个性化手术决策的临床潜力。
