基于¹⁸F-FDG PET/CT影像组学预测结直肠癌微卫星不稳定状态的研究进展

Research Progress on Radiomics Based on ¹⁸F-FDG PET/CT for Predicting Microsatellite Instability Status in Colorectal Cancer

摘要: 结直肠癌是全球高发恶性肿瘤，其发生发展与多种基因改变密切相关。微卫星不稳定状态，尤其是高度微卫星不稳定性，已成为指导结直肠癌免疫治疗、化疗及预后评估的重要标志物。目前，临床常用的MSI检测方法包括免疫组织化学和聚合酶链反应，均依赖术后组织样本，存在有创性、采样主观、无法动态监测等不足，也难以全面反映肿瘤内部的异质性。因此，术前无创、精准预测MSI状态具有重要临床意义。¹⁸F-FDG PET/CT作为功能成像技术，可定量评估肿瘤葡萄糖代谢活性，其代谢参数如肿瘤代谢体积、病灶糖酵解总量及异质性指数等，已被初步证实与结直肠癌MSI状态及HER2表达存在关联。近年来，影像组学通过高通量提取PET/CT图像中的定量特征，进一步揭示了肿瘤的微观异质性，为术前无创预测MSI状态提供了新工具。本文系统回顾¹⁸F-FDG PET/CT代谢参数及影像组学方法在预测结直肠癌MSI状态中的研究进展，分析其临床价值、面临挑战及未来发展方向，为结直肠癌个体化治疗决策提供理论依据。

Abstract: Colorectal cancer is a highly prevalent malignancy worldwide, and its development and progression are closely associated with multiple genetic alterations. Microsatellite instability (MSI) status, particularly high-level microsatellite instability, has become an important biomarker for guiding immunotherapy, chemotherapy, and prognostic assessment in colorectal cancer. Currently, commonly used clinical methods for MSI detection include immunohistochemistry and polymerase chain reaction, both of which rely on postoperative tissue samples. These approaches are invasive, subject to sampling bias, and incapable of dynamic monitoring, and they also fail to comprehensively reflect intratumoral heterogeneity. Therefore, preoperative noninvasive and accurate prediction of MSI status holds significant clinical importance. As a functional imaging technique, ¹⁸F-FDG PET/CT enables quantitative assessment of tumor glucose metabolic activity. Its metabolic parameters, such as metabolic tumor volume, total lesion glycolysis, and heterogeneity indices, have been preliminarily shown to be associated with MSI status and HER2 expression in colorectal cancer. In recent years, radiomics has further revealed the microscopic heterogeneity of tumors by extracting high-throughput quantitative features from PET/CT images, offering a novel tool for the preoperative noninvasive prediction of MSI status. This article systematically reviews the research progress of ¹⁸F-FDG PET/CT metabolic parameters and radiomics approaches in predicting MSI status in colorectal cancer, analyzes their clinical value, current challenges, and future development directions, and aims to provide a theoretical basis for individualized treatment decision-making in colorectal cancer.