Targeting the Tumor Microenvironment with Radiolabeled Antibodies: Bridging Immunotherapy and Molecular Imaging

Radiolabeled monoclonal antibodies represent a promising approach to integrate molecular imaging with immunotherapy for cancer diagnosis and treatment. These antibodies target immune checkpoints and tumor-associated antigens, enabling non-invasive visualization of tumor dynamics through PET and SPECT imaging. Evidence from preclinical and clinical studies suggests that such imaging can provide insights into antibody distribution, immune cell infiltration, and potential treatment responses within the tumor microenvironment. By combining diagnostic and therapeutic capabilities, antibody-based theranostics offer opportunities for personalized treatment planning and understanding mechanisms of resistance. This review highlights current advances in antibody-based molecular imaging, discusses challenges in translation, and explores future directions for integrating imaging with immuno-oncology strategies to improve patient outcomes. Radiolabeled antibodies allow non-invasive assessment of tumor–immune interactions, supporting adaptive treatment planning and bridging immunotherapy with molecular imaging.