A Miniaturized In Vivo Fluorescence Microscopy Method for Monitoring Circulating Tumor Cells in Freely Moving Animals

Metastasis is the leading cause of death in tumor patients, with circulating tumor cells (CTCs) serving as key biomarkers for tumor progression, metastasis, and recurrence. CTC quantity is closely linked to tumor dynamics, which are influenced by biological rhythms. Studying CTC distribution under various physiological conditions provides insights into metastasis mechanisms. However, due to the low abundance of CTCs, detection accuracy is limited, especially with small blood samples, making continuous data collection challenging. To address this, we developed a dual-channel miniaturized in vivo fluorescence microscopy system for real-time monitoring of CTCs in experimental animals. This system, which can be fixed to the head or back, enables dynamic, quantitative analysis of CTCs in the circulatory system. It offers a valuable tool for investigating tumor metastasis rhythms, drug evaluation, and prognostic assessment in freely moving animals, advancing research in metastasis mechanisms and cancer treatment.