Immature and chaotic vascular networks with critically increased intervascular distances are characteristic features of malignant tumors. Spatial and temporal heterogeneities of blood flow and associated availabilities of O₂, together with limited diffusive O₂ transport, and -in some patients- anemia, obligatorily lead to tumor hypoxia (= critically reduced O₂ levels) on macro- and microscopic scales. This detrimental condition, recently classified as a key hallmark of malignant growth, acts (a) as a barrier in most antitumor treatments, and (b) leads to malignant progression based on hypoxia-induced changes of the genome, transcriptome, and proteome, and finally to poor patient survival. This knowledge is, to a great extent, based on the systematic detection of tumor hypoxia in the clinical setting since the late 1980s. Precise assessment of the tumor oxygenation status was made possible using minimally invasive polarographic pO₂ microsensors in a series of research projects. To assess tumor hypoxia in the clinical setting, it is highly desirable to use technologies with (a) high spatial and temporal resolutions, (b) the capability to judge the severity of tumor hypoxia, (c) to allow mapping of pO₂ of the whole tumor mass, and (d) to enable serial investigations in order to verify treatment-related changes in tumor hypoxia. Selection and treatment of cancer patients according to their individual tumor oxygenation/hypoxia status for intensified and/or personalized hypoxia-targeted treatment strategies should be the ultimate goal.

血管间距离急剧增加的不成熟和混乱的血管网络是恶性肿瘤的特征。血流的时空异质性和 O _{2 的}相关可用性，以及有限的弥散 O ₂运输，以及 - 在某些患者中 - 贫血，必然导致肿瘤缺氧（= O ₂严重减少水平）在宏观和微观尺度上。这种有害情况最近被归类为恶性生长的关键标志，它 (a) 在大多数抗肿瘤治疗中充当屏障，和 (b) 基于缺氧诱导的基因组、转录组和蛋白质组的变化导致恶性进展，以及最终以可怜的患者生存。这些知识在很大程度上是基于 1980 年代后期以来临床环境中对肿瘤缺氧的系统检测。使用微创极谱 pO ₂可以精确评估肿瘤氧合状态一系列研究项目中的微传感器。为了评估在临床肿瘤缺氧，非常理想的是使用的技术与（a）中的高空间和时间分辨率，（b）中的能力来判断肿瘤缺氧的严重程度，（C），以允许PO的映射₂的整个肿瘤块，以及 (d) 进行系列调查，以验证肿瘤缺氧的治疗相关变化。根据个体肿瘤氧合/缺氧状态选择和治疗癌症患者，以进行强化和/或个性化的缺氧靶向治疗策略应该是最终目标。