Preclinical Studies on Nanocarrier-Mediated Delivery of Radiosensitizing Agents to Brain and Pancreatic Cancer with a Future Projection to Liver Cancer

Radiotherapy is one of the primary treatment modalities in oncology. The therapeutic effectiveness of irradiation is dependent on the balance between the tumor control probability (TCP) and the normal tissue complication probability (NTCP), i.e., the induction of side effects. Combination treatment of irradiation with chemotherapy targeted to a tumor or using immune-modulating agents could significantly benefit from nanotechnology strategies, allowing localized delivery of therapeutic compounds to the irradiated tumor volume. When used in combination with irradiation, drugs should be selected on their interaction with the 6 R’s, the six Hallmarks of Radiobiology, to sensitize the radiation effect on the molecular, cellular, and tissue level, and in addition to that, positively impact the TCP/NTCP balance. This chapter presents and discusses preclinical data on the combination of irradiation and nanocarrier-mediated delivery of drugs in the brain, pancreatic, and liver cancer. Before implementation into the clinical practice, nanotechnology demands further technical and biological studies on drug loading efficacy, drug release, cellular and tissue uptake, biodistribution, tumor-targeting methods, and administration routes to the patient. Notwithstanding those challenges, the combination of local radiotherapy with tumortargeted nanocarrier-delivered radiosensitizers, as well as the use of radiosensitizing nanoparticles, are exciting developments with a great clinical prospect.