Background:Hypoxia, a state of low oxygen level within a tissue, is often present in primary and secondary liver tumors. At the molecular level, the tumor cells’ response to hypoxic stress induces proteomic and genomic changes which are largely regulated by proteins called hypoxia-induced factors (HIF). These proteins have been found to drive tumor progression and cause resistance to drug- and radiation-based therapies, ultimately contributing to a tumor’s poor prognosis. Several imaging modalities have been developed to visualize tissue hypoxia, providing insight into a tumor’s microbiology.Methods:A systematic literature search was conducted in PubMed, EMBASE, Cochrane, and Google Scholar for all reports related to hypoxia on liver tumors. All relevant studies were summarized.Results:This review will focus on the impact of hypoxia on liver tumors and review PET-, MRI-, and SPECT-based imaging modalities that have been developed to predict and assess a tumor’s response to radiation therapy, with a focus on liver cancers.Conclusion:While there are numerous studies that have evaluated the impact of hypoxia on tumor outcomes, there remains a relative paucity of data evaluating and quantifying hypoxia within the liver. Novel and developing non-invasive imaging techniques able to provide functional and physiological information on tumor hypoxia within the liver may be able to assist in the treatment planning of primary and metastatic liver lesions.
背景：缺氧，即组织内氧含量降低的状态，常见于原发性及继发性肝脏肿瘤。在分子层面，肿瘤细胞对缺氧应激的反应会诱导蛋白质组和基因组的改变，这些变化主要受缺氧诱导因子（HIF）调控。研究发现，这些蛋白质会驱动肿瘤进展并导致对药物及放射治疗的抵抗，最终导致肿瘤预后不良。目前已有多种成像技术被开发用于可视化组织缺氧状态，从而揭示肿瘤的微生物学特征。 方法：在PubMed、EMBASE、Cochrane及Google Scholar数据库中对所有涉及肝脏肿瘤缺氧相关研究的报告进行了系统性文献检索，并对所有相关研究进行了总结。 结果：本综述将重点关注缺氧对肝脏肿瘤的影响，并回顾基于PET、MRI和SPECT的成像技术，这些技术已被开发用于预测和评估肿瘤（特别是肝癌）对放射治疗的反应。 结论：尽管已有大量研究评估缺氧对肿瘤预后的影响，但针对肝脏内缺氧状态的评估与量化数据仍相对缺乏。新兴及发展中的无创成像技术能够提供肝脏肿瘤缺氧的功能与生理信息，可能有助于原发性及转移性肝脏病灶的治疗规划。
Impact of Hypoxia on Radiation-Based Therapies for Liver Cancer
肿瘤(癌症)患者之家