Boron neutron capture therapy for glioblastoma multiforme: Enhanced drug delivery and antitumor effect following blood-brain barrier disruption induced by focused ultrasound

Aim: This study investigated whether the efficacy of boron neutron capture therapy was enhanced by means of intravenous administration of boronophenylalanine (BPA) with blood-brain barrier disruption induced by focused ultrasound (FUS). Materials & methods: BPA was administered, followed by pulsed FUS, and the boron concentration in the treated brains was quantified by inductively coupled plasma mass spectroscopy. Growth of the firefly luciferase-labeled glioma cells was monitored through noninvasive biophotonic imaging. Finally, the brain tissue was histologically examined after sacrifice. Results: Compared with the nonsonicated tumor group, animals treated with an injection of 500 mg/kg of BPA followed by FUS exhibited not only significantly increased accumulation of the drug at the sonicated tumor site, but also a significantly elevated tumor-to-normal brain drug ratio (p < 0.05). Discussion: The data demonstrated that FUS significantly enhances the tumor-to-normal brain drug ratio in the sonicated tumor and subsequently the efficacy of boron neutron capture therapy.