Title: Diffusion-weighted MRI-guided needle biopsies permit quantitative tumor heterogeneity assessment and cell load estimation Show Chinese title

Title: 弥散加权磁共振成像引导的针刺活检允许定量评估肿瘤异质性和细胞负荷估计

Abstract: Quantitative information on tumor heterogeneity and cell load could assist in designing effective and refined personalized treatment strategies. It was recently shown by us that such information can be inferred from the diffusion parameter D derived from the diffusion-weighted MRI (DWI) if a relation between D and cell density can be established. However, such relation cannot a priori be assumed to be constant for all patients and tumor types. Hence to assist in clinical decisions in palliative settings, the relation needs to be established without tumor resection. It is here demonstrated that biopsies may contain sufficient information for this purpose if the localization of biopsies is chosen as systematically elaborated in this paper. A superpixel-based method for automated optimal localization of biopsies from the DWI D-map is proposed. The performance of the DWI-guided procedure is evaluated by extensive simulations of biopsies. Needle biopsies yield sufficient histological information to establish a quantitative relationship between D-value and cell density, provided they are taken from regions with high, intermediate, and low D-value in DWI. The automated localization of the biopsy regions is demonstrated from a NSCLC patient tumor. In this case, even two or three biopsies give a reasonable estimate. Simulations of needle biopsies under different conditions indicate that the DWI-guidance highly improves the estimation results. Tumor cellularity and heterogeneity in solid tumors may be reliably investigated from DWI and a few needle biopsies that are sampled in regions of well-separated D-values, excluding adipose tissue. This procedure could provide a way of embedding in the clinical workflow assistance in cancer diagnosis and treatment based on personalized information. Show Chinese abstract

Abstract: 肿瘤异质性和细胞负荷的定量信息可以帮助设计有效的个性化治疗策略。 我们最近的研究表明，如果能够建立扩散参数D与细胞密度之间的关系，那么此类信息可以从扩散加权磁共振成像（DWI）中的D值推断出来。 然而，不能事先假定这种关系对所有患者和肿瘤类型都是恒定的。 因此，为了辅助姑息性临床决策，需要在不进行肿瘤切除的情况下建立这种关系。 本文证明，如果活检的位置选择经过系统性的详细规划，活检样本可能包含足够的信息来实现这一目的。 提出了一种基于超像素的自动化方法，用于从DWI D图中自动定位最优活检位置。 通过广泛的活检模拟评估了DWI引导程序的性能。 针吸活检可以提供足够的组织学信息，以建立D值与细胞密度之间的定量关系，前提是在DWI中高、中、低D值的区域获取活检样本。 展示了一个NSCLC患者肿瘤活检区域的自动化定位。 在这种情况下，即使两到三个活检也能给出合理的估计。 不同条件下针吸活检的模拟结果显示，DWI引导显著提高了估计结果。 可以从DWI和几个在分离良好的D值区域采样的针吸活检中可靠地研究实体瘤中的肿瘤细胞密度和异质性，排除脂肪组织。 此过程可以为基于个性化信息的癌症诊断和治疗提供一种嵌入临床工作流程的方法。