56 Researchers have shown that focused ultrasound (FUS) can help deliver immunomodulating agents to fight glioblastoma and metastatic brain tumours. This is a big step forward in the treatment of brain cancer. This innovative approach, which utilises ultrasound waves combined with microbubbles, has shown promising results in increasing the permeability of the blood-brain barrier (BBB), allowing for targeted therapeutic delivery directly to the brain. For patients with these aggressive and frequently treatment-resistant cancers, the study by a team from Concordia University and Queen’s University offers new hope. The findings were published in the Journal of Controlled Release. Glioblastoma, the most common primary malignant brain tumour in adults, is notorious for its poor prognosis and resistance to conventional therapies. Despite aggressive treatment regimens, including surgery, radiation, and chemotherapy, the median survival rate for glioblastoma patients remains around 12–14 months. The presence of the BBB, which acts as a formidable barrier to drug delivery and prevents many potentially effective therapies from reaching tumour sites within the brain, increases the difficulty of treating brain tumours. Metastatic brain tumours, which originate from cancers elsewhere in the body, present additional challenges. These secondary brain tumours also suffer from the same obstacles posed by the BBB and the hostile tumour microenvironment, which further limits the efficacy of standard treatments. The study explored the use of FUS to temporarily disrupt the BBB, allowing for the delivery of immunomodulating agents directly to brain tumours. This technique harnesses the power of ultrasound waves focused on specific areas of the brain. When combined with microbubbles, which oscillate and expand under ultrasound, the BBB can be selectively and reversibly opened. This enables therapeutic agents, such as antibodies, immune cells, and cytokines, to penetrate the brain tissue more effectively. The researchers used FUS in combination with various immunotherapeutic agents, including monoclonal antibodies and immune cells. In preclinical models, this approach demonstrated a significant increase in the delivery and efficacy of these agents within brain tumours. The study showed that using low-intensity pulsed ultrasound along with anti-PD-1 checkpoint inhibitors improved the delivery of antibodies to the tumour site and the recruitment of peripheral antigen-presenting cells, which led to better control of the tumour. In a notable experiment, T-DM1, an antibody-drug conjugate, was used in a mouse model of brain metastases that were positive for HER2. The results showed that FUS treatment right after T-DM1 administration greatly increased the drug’s delivery to the tumour cells, making it more effective as a medicine. The successful application of FUS-assisted delivery in preclinical models paves the way for clinical trials. Ongoing trials are currently evaluating the safety and efficacy of this technique in patients with glioblastoma and other brain tumours. Early results are encouraging, suggesting that FUS could become a valuable tool in the arsenal against brain cancer. Moreover, the potential applications of FUS extend beyond oncology. The ability to precisely target and modulate the BBB opens up possibilities for treating other neurological conditions, such as Alzheimer’s disease and amyotrophic lateral sclerosis (ALS), where drug delivery to the brain remains a significant challenge.