... metastasizes to the brain, an ectopic site, the permeability of the BTB of the breast cancer tumor growing in the brain is lower than the BTB of the original tumor in breast tissue, the ortho-topic ... over 600 to 700 minutes. We com-pared the permeability of the BTB of RG-2 gliomas grownwithin the brain, the orthotopic site, to that of the BTB of RG-2 gliomas grown outside the brain in the temporalisskeletal ... permeability of the BTB of orthotopic and ectopic RG-2 malignant gliomas and define the upperlimit of pore size within the BTB of brain tumors and peripheral tumors. We determined the differences in the permeability...