Nanocarrier-chemotherapeutic accumulation in the tumor is highly dependent on the degree of each individual tumor’s EPR. The tumor permeability not only differs between patients but also spatially within the same tumor. For this reason, the ability to visualize and monitor the extravasation and accumulation of the nanocarriers within the tumor will greatly aid in planning the optimal treatment regime for each patient, leading to personalized tumor therapy.

Researchers in the department of biomedical engineering at Georgia Tech/Emory demonstrated that nanocarriers can be tracked in vivo non-invasively. A 100 nm long circulating liposomal nanocarrier encapsulating gadodiamide introduced intravenously, induced strong T2-shortening in a 9.4 T MRI system. Nanocarrier accumulation in an orthotropic brain tumor was quantified by brain imaging after the nanocarriers were cleared from the blood circulation by the reticuloendothelial system. Adequate tumor dosing was achieved due to the long circulation half-life of the nanocarriers. Therefore, by optimizing nanocarrier properties such that it: a) can be non-invasively tracked in therapeutically safe doses; b) has a long circulation half-life to allow for tumor accumulation via leaky vasculature; and c) is cleared from circulation in 2–3 days enabled low-noise detection of tumor-accumulated nanocarriers. Such a system can be used to optimize tumor dosing of nanocarriers on a patient-to-patient basis, allowing for personalized tumor therapy.