Fig. 7.

Heterogeneity of blood-brain barrier disruption and drug concentration in the experimental model (mice) of breast cancer brain metastases (from reference (56)). ¹⁴C-lapatinib was measured in normal brain and different brain metastases by quantitative autoradiography at 2 h (a-c) and 12 h (d-f) following the oral administration of 100 mg/kg ¹⁴C-lapatinib. Signal from metastatic cells labelled with EGFP (a,d), Texas Red 3kD dextran (b,e), and ¹⁴C-lapatinib (c,f) indicate the location of tumor cells, the integrity of the BBB, and the concentration of drug, respectively. The concentrations of lapatinib, as well as disruption of BBB, were highly variable within and between the metastatic breast cancer lesions in the brain.