Molecular imaging for cancer immunotherapy

The success of immune checkpoint blockade has reaffirmed the importance of the immune system in cancer treatment. Immunotherapy enables the body's own immune system to fight tumor cells. However, the complex tumor microenvironment and its interaction with the immune system remain a mystery. The efficacy of immunotherapy is often affected by tumor heterogeneity. Molecular imaging techniques, such as single photon emission computed tomography and positron emission tomography, enable noninvasive whole‐body imaging of tumor and immune cell signatures. Noninvasive molecular imaging can also be used to monitor the treatment response of tumors, thereby achieving personalized response assessment, which may ultimately lead to improved clinical management, development of individualized treatments, and reliable prognosis. This article reviews recent research in immunotherapy response assessment, immune T‐cell imaging, immune checkpoint imaging, and radiomics/radiogenomics in immunotherapy. To date, these studies have primarily comprised exploratory preclinical imaging with preliminary results indicating that biomarker molecular imaging may have a role to play in the assessment of immunotherapy. Therefore, the principle of selecting patients for immunotherapy based on imaging results is feasible.