Application of non-invasive imaging on cell tracking of adoptive cell therapy: A systemic review

Adoptive cell therapy (ACT) has emerged as a promising treatment for advanced or recurrent cancer patients. It is a challenge to dynamically monitor and modulate the biological behavior and function of infused cells to predict the efficacy of ACT and manage its adverse effects. Numerous studies have endeavored to monitor ACT non-invasively using diverse imaging modalities. Despite each modality's inherent advantages and disadvantages, there remains substantial room for advancement in in vivo cell tracking, making non-invasive cell tracking a continuing research priority. This review examines the current state of radionuclide, optical, magnetic resonance, and magnetic particle imaging in cell tracking, analyzing their adaptability across various application scenarios and discussing the challenges each modality encounters. Finally, combined with the current research status, the review proposes prospective directions for noninvasive molecular imaging to address the dynamic monitoring requirements of high security, high sensitivity, versatility, and longevity in cell tracking. The advancement of molecular imaging technology is expected to enhance understanding of ACT function mechanisms, optimize combination treatment strategies, and bolster the efficacy and safety of ACT.