Application of Nanotechnology in the Diagnosis and Treatment of Brain Metastases

The incidence of brain metastases is increasing. While chemotherapies, targeted therapies, and immunotherapies have advanced the treatment of many primary tumors, the blood–brain barrier (BBB), heterogeneity of metastases, and unique CNS environment limit their efficacy for brain metastases. With some applications in human clinical trials, others already with FDA approval, and most in preliminary research development, nanoparticles represent an attractive, theranostic technology for the diagnosis and treatment of brain metastases. Nanoparticles may be used to traffic drugs in crossing the BBB, target tumor cells, sustain slow drug release, limit drug metabolism, photothermally eliminate tumor cells, provide imaging contrast and real-time tumor localization, increase radiosensitivity, and modulate the immunosuppressive tumor environment. We evaluate the efficacy of various nanoparticle formulations including polymeric, liposomal, and metallic nanoparticles for these applications. Future perspectives on the integration of nanoparticle technology in clinical settings are considered, emphasizing the need for continued research and development.