Magnetic seeds provide new cancer therapy

UCL scientists have developed a novel cancer therapy that uses an MRI scanner to guide a magnetic seed through the brain to heat and destroy tumours.

cancer therapy
Image credit: Mark Lythgoe (UCL)

The cancer therapy, demonstrated in mice, is called ‘minimally invasive image-guided ablation’ or MINIMA. It comprises a ferromagnetic thermoseed navigated to a tumour using magnetic propulsion gradients generated by an MRI scanner, before being remotely heated to kill nearby cancer cells.

Published in Advanced Science, the team said its findings establish proof-of-concept for precise and effective treatment of hard-to-reach glioblastoma, alongside other cancers such as prostate, that could benefit from less invasive therapies.

Senior author Professor Mark Lythgoe, UCL Centre for Advanced Biomedical Imaging, said that MINIMA has potential to avoid traditional side effects by precisely heating the tumour without harming healthy tissues.

In a study, the UCL team demonstrated three key components of MINIMA: precise seed imaging, navigation through brail tissue using a tailored MRI system tracked to within 0.3mm accuracy, and eradicating the tumour by heating it in a mouse model.

Cancer patients set to EMBRaCE wearable technologies

Handheld aCAP device eliminates cancer cells with plasma

Ferromagnetic thermoseeds are spherical in shape, 2mm in size and made of a metal alloy. They are implanted superficially into tissue before being navigated to the cancer.

Lead author Rebecca Baker, UCL Centre for Advanced Biomedical Imaging, said: “Using an MRI scanner to deliver a therapy in this way allows the therapeutic seed and the tumour to be imaged throughout the procedure, ensuring the treatment is delivered with precision and without having to perform open surgery.” 

MRI scanners are readily available in hospitals globally and are pivotal in diagnosing diseases such as cancer. The UCL researchers believe their work has potential to elevate an MRI scanner from a diagnostic device to a therapeutic platform.

Co-author Dr Lewis Thorne, a consultant neurosurgeon at the National Hospital for Neurology and Neurosurgery said: “I treat patients with the most common form of brain cancer, glioblastoma. 

“Following surgery, the average survival time is 12-18 months. MINIMA can successfully destroy cancer in a mouse and has the potential to extend survival and limit damage to adjacent brain tissues in patients.”

In the longer term, Professor Lythgoe said the team will change the shape of the seed to act as a tiny cutting scalpel that could be guided through tissue, which would allow surgeons to perform remotely controlled operations to ‘revolutionise’ non-invasive surgery.

The study was supported with funding by the Rosetrees Trust and John Black Charitable Foundation.