Imaging‐Based Efficacy Evaluation of Cancer Immunotherapy in Engineered Tumor Platforms and Tumor Organoids

Abstract Cancer immunotherapy is used to treat tumors by modulating the immune system. Although the anticancer efficacy of cancer immunotherapy has been evaluated prior to clinical trials, conventional in vivo animal and endpoint models inadequately replicate the intricate process of tumor elimination and reflect human‐specific immune systems. Therefore, more sophisticated models that mimic the complex tumor‐immune microenvironment must be employed to assess the effectiveness of immunotherapy. Additionally, using real‐time imaging technology, a step‐by‐step evaluation can be applied, allowing for a more precise assessment of treatment efficacy. Here, an overview of the various imaging‐based evaluation platforms recently developed for cancer immunotherapeutic applications is presented. Specifically, a fundamental technique is discussed for stably observing immune cell‐based tumor cell killing using direct imaging, a microwell that reproduces a confined space for spatial observation, a droplet assay that facilitates cell–cell interactions, and a 3D microphysiological system that reconstructs the vascular environment. Furthermore, it is suggested that future evaluation platforms pursue more human‐like immune systems.