PET/CT molecular imaging in the era of immune-checkpoint inhibitors therapy

Abstract

Cancer immunotherapy, especially immune-checkpoint inhibitors (ICIs), has paved a new way for the treatment of many types of malignancies, particularly advanced-stage cancers. Accumulating evidence suggests that as a molecular imaging modality, positron emission tomography/computed tomography (PET/CT) can play a vital role in the management of ICIs therapy by using different molecular probes and metabolic parameters. In this review, we will provide a comprehensive overview of the clinical data to support the importance of ¹⁸F-fluorodeoxyglucose PET/CT (¹⁸F-FDG PET/CT) imaging in the treatment of ICIs, including the evaluation of the tumor microenvironment, discovery of immune-related adverse events, evaluation of therapeutic efficacy, and prediction of therapeutic prognosis. We also discuss perspectives on the development direction of ¹⁸F-FDG PET/CT imaging, with a particular emphasis on possible challenges in the future. In addition, we summarize the researches on novel PET molecular probes that are expected to potentially promote the precise application of ICIs.

Keywords: immune-checkpoint inhibitors (ICIs); metabolic parameter; molecular imaging; molecular probe; positron emission tomography/computed tomography (PET/CT); tumor microenvironment (TME).