Schmitz Fabian, Voigtländer Hendrik, Strauss Dimitrios, Schlemmer Heinz-Peter, Kauczor Hans-Ulrich, Jang Hyungseok, Sedaghat Sam
Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany.
Division of Radiology, German Cancer Research Center, Heidelberg, Germany.
BMC Cancer. 2024 Dec 30;24(1):1589. doi: 10.1186/s12885-024-13339-7.
Soft-tissue sarcomas are rare tumors of the soft tissue. Recent diagnostic studies mainly dealt with conventional image analysis and included only a few cases. This study investigated whether low- and high-proliferative soft tissue sarcomas can be differentiated using conventional imaging and radiomics features on MRI.
In this retrospective study, soft tissue sarcomas were separated into two groups according to their proliferative activity: high-proliferative (Ki-67 ≥ 20%) and low-proliferative soft tissue sarcomas (Ki-67 < 20%). Several radiomics features, and various conventional imaging features on MRI like tumor heterogeneity, peritumoral edema, peritumoral contrast-enhancement, percentage of ill-defined tumor margins, Apparent Diffusion Coefficient (ADC) values, and area under the curve (AUC) in contrast dynamics were collected. These imaging features were independently compared with the two mentioned groups.
118 sarcoma cases were included in this study. Metastases were more prevalent in high-proliferative soft tissue sarcomas (p < 0.001), and time till metastasis negatively correlated with the Ki-67 proliferation index (k -0.43, p = 0.021). Several radiomics features representing intratumoral heterogeneity differed significantly between both groups, especially in T2-weighted (T2w) and contrast-enhanced T1-weighted (CE-T1w) sequences. Peritumoral contrast enhancement and edema were significantly more common in soft tissue sarcomas with a high Ki-67 index (p < 0.001). Tumor configuration, heterogeneity, and ill-defined margins were commonly seen in high-proliferative soft tissue sarcomas (p = 0.001-0.008). Diffusion restriction (ADC values) and contrast dynamics (AUC values) did not present significant differences between low- and high-proliferative soft tissue sarcomas.
Several radiomics and conventional imaging features indicate a higher Ki-67 proliferation index in soft tissue sarcomas and can therefore be used to distinguish between low- and high-proliferative soft tissue sarcomas.
软组织肉瘤是软组织的罕见肿瘤。近期的诊断研究主要涉及传统图像分析，且病例数较少。本研究调查了能否利用MRI上的传统成像和影像组学特征区分低增殖性和高增殖性软组织肉瘤。
在这项回顾性研究中，软组织肉瘤根据其增殖活性分为两组：高增殖性（Ki-67≥20%）和低增殖性软组织肉瘤（Ki-67<20%）。收集了几个影像组学特征，以及MRI上的各种传统成像特征，如肿瘤异质性、瘤周水肿、瘤周对比增强、边界不清的肿瘤边缘百分比、表观扩散系数（ADC）值和对比剂动力学曲线下面积（AUC）。将这些成像特征分别与上述两组进行比较。
本研究纳入了118例肉瘤病例。转移在高增殖性软组织肉瘤中更为常见（p<0.001），转移发生时间与Ki-67增殖指数呈负相关（k=-0.43，p=0.021）。两组之间，几个代表肿瘤内异质性的影像组学特征存在显著差异，尤其是在T2加权（T2w）和对比增强T1加权（CE-T1w）序列中。瘤周对比增强和水肿在Ki-67指数高的软组织肉瘤中明显更常见（p<0.001）。肿瘤形态、异质性和边界不清在高增殖性软组织肉瘤中较为常见（p=0.001-0.008）。低增殖性和高增殖性软组织肉瘤之间，扩散受限（ADC值）和对比剂动力学（AUC值）没有显著差异。
几个影像组学和传统成像特征表明软组织肉瘤中Ki-67增殖指数较高，因此可用于区分低增殖性和高增殖性软组织肉瘤。
