Blood–brain barrier breached to treat cancer

New Scientist : Thanks to the close packing of the cells that line the blood vessels in our brains, only the smallest molecules can pass from the circulatory system into the central nervous system. Bacteria and viruses are too large to pass through the blood–brain barrier (BBB), but so too are antibiotics and drugs that treat cancer. Six years ago researchers from Harvard University and the University of Toronto used ultrasound to breach the BBB in lab rabbits by inducing microbubbles in the blood to vibrate and push apart the barrier’s cells. Now a team from a Paris-based medical startup called CarThera has demonstrated a way of implementing that approach in human subjects. Rather than direct the ultrasound through the skull, as was done in the case of the rabbits, the researchers surgically implant an ultrasound transducer. The four patients in the ongoing trial all suffer from recurrent gliobastoma. After their tumors had been surgically removed, the transducers were installed through the same hole in the skull. Once a month the transducers are switched on while the patients receive normal chemotherapy. The success of the therapy in preventing the cancer’s recurrence is likely to be known in a few months’ time.