Biological Rationale and Advantages of Image-Guided Immunotherapy

Intratumoral injection of immunotherapy enables direct delivery into the tumor microenvironment with a wide array of therapeutics, including immune check point inhibitors, oncolytic viruses, and chimeric antigen receptor T cell therapy. Intratumoral immunotherapy had been demonstrated to increase tumor cell lysis, local and distant antigen presentation, immune cell activation and infiltration of the tumor, and systemic immune activation leading to abscopal effects. Despite limited clinical translation over the past 10 years, image-guided intratumoral immunotherapy has been demonstrated to be safe with many advantages over systemic therapy. The landscape of intratumoral immunotherapy is poised to expand substantially with multiple therapies pending approval based on compelling clinical trial data. Interventional radiologists have an opportunity to play an active role in intratumoral immunotherapy programs, specifically with developing protocols, procedural techniques, devices, and drug delivery materials to overcome limitations that have precluded clinical translation.