Fig. 6.
Intratumoral distribution of therapeutic agents as a function of perfused vessel fraction for drugs with (A) low binding affinity and (B) high binding affinity (details in Supporting Information). Three curves in each panel show the intratumoral distribution of drugs of three sizes (1, 10, and 60 nm) versus the fraction of perfused vessels. The curves demonstrate that the intratumoral distribution of drugs of all three sizes increases with the fraction of perfused vessels, but in a nonlinear manner. The increase is more substantial for smaller drugs than for larger drugs. Intratumoral distribution is defined as the fraction of the tumor extravascular space that the drug is bound to cancer cells in amounts higher than 1% of the concentration at the inlet of the vascular network.