Nanoparticles as a promising method to enhance the abscopal effect in the era of new targeted therapies.

Over the last decade, immunotherapy has emerged as a hopeful alternative in cancer therapy. Different drugs are used to stimulate the immune system and block negative immune regulatory pathways, known as "immune checkpoint inhibitors (ICI)". Although clinical studies have reported efficacy and safety with the use of ICI, only a small group of patients have obtained a clinical benefit. Because of this, immunomodulation based on immunogenic cell death produced by radiotherapy (RT) has been well positioned as an alternative to increase the clinical effect on the primary neoplasm, but also in distant tumours, a phenomenon known as the "abscopal effect". Early clinical outcomes with RT-ICI combination are promising, but the rate of abscopal responses remains low. These developments have opened a path to evaluate the use of nanotechnology as antigen-capturing nanoparticles (AC-NPs) for improving clinical outcomes in metastatic disease treated with RT-ICI. In this review, we aim to highlight the basic characteristics of nanoparticles and its application in oncology, focusing on their potential to enhance abscopal responses.