Pretargeted nuclear imaging and radiotherapy have recently attracted increasing attention for diagnosis and treatment of cancer with nanomedicines. This is because it conceptually offers better imaging contrast and therapeutic efficiency while reducing the dose to radiosensitive tissues compared to conventional strategies. In conventional imaging and radiotherapy, a directly radiolabeled nano-sized vector is administered and allowed to accumulate in the tumor, typically on a timescale of several days. In contrast, pretargeting is based on a two-step approach. First, a tumor-accumulating vector carrying a tag is administered followed by injection of a fast clearing radiolabeled agent that rapidly recognizes the tag of the tumor-bound vector in vivo. Thereby, pretargeting circumvents the use of long-lived radionuclides that is a necessity for sufficient tumor accumulation and target-to-background ratios using conventional approaches.

In this review, we give an overview of recent advances in pretargeted imaging strategies. We will critically reflect on the advantages and disadvantages of current state-of-the-art conventional imaging approaches and compare them to pretargeted strategies. Thereby, we will discuss the pretargeted imaging concept and the involved chemistry. Finally, we will discuss the steps forward in respect to clinical translation, and how pretargeted strategies could be applied to improve state-of-the-art radiotherapeutic approaches.

预靶向核成像和放射疗法最近已引起越来越多的关注，以纳米药物诊断和治疗癌症。这是因为与传统策略相比，它在概念上提供了更好的成像对比度和治疗效率，同时减少了对放射敏感性组织的剂量。在常规的成像和放射疗法中，通常在几天的时间尺度上，施用直接放射性标记的纳米级载体并使其在肿瘤中积累。相反，预定位是基于两步法。首先，施用携带标签的肿瘤聚集载体，然后注射快速清除的放射性标记试剂，该试剂在体内快速识别肿瘤结合载体的标签。从而，

在这篇综述中，我们概述了预靶向成像策略的最新进展。我们将批判性地反思当前最先进的常规成像方法的优缺点，并将它们与预定目标的策略进行比较。因此，我们将讨论预定位成像的概念和所涉及的化学。最后，我们将讨论有关临床翻译的步骤，以及如何使用预定目标的策略来改进最新的放射治疗方法。