An MRI scanner has been used to guide a magnetic seed through an animal brain to heat and destroy cancer tumours without harming healthy tissues, British researchers have reported.
Scientists at UCL, UK, say the therapy, called minimally invasive image-guided ablation (MINIMA) was demonstrated in mice and could eventually benefit cancer patients by reducing recovery times and minimising side effects.
It uses magnetic propulsion gradients generated by an MRI scanner to navigate a ferromagnetic thermoseed to a tumour before being remotely heated to kill nearby cancer cells.
The authors of the study, published in the latest edition of *Advanced Science*, say their findings establish proof-of-concept for precise and effective treatment of hard-to-reach glioblastoma.
They say the novel therapy could also be used for other cancers such as prostate, which would benefit from less invasive therapies.
Senior author, Professor Mark Lythgoe, of UCL Centre for Advanced Biomedical Imaging, said: “MINIMA is a new MRI-guided therapy that has the potential to avoid traditional side effects by precisely treating the tumour without harming healthy tissues.
“Because the heating seed is magnetic, the magnetic fields in the MRI scanner can be used to remotely steer the seed through tissue to the tumour. Once at the tumour, the seed can then be heated, destroying the cancer cells, while causing limited damage to surrounding healthy tissues.”
The UCL team said their study showed that three key components of MINIMA were completed accurately: precise seed imaging; navigation through brain tissue using a tailored MRI system, which was tracked to 0.3mm accuracy; and, in a mouse model, eradicating the tumour by heating it.
Lead author Rebecca Baker, of 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.
“This could be beneficial to patients by reducing recovery times and minimising the chance of side effects.”
The authors add that MINIMA has the potential to elevate an MRI scanner from a diagnostic device to a therapeutic platform.
Prof Lythgoe added: “In the longer term, we 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, revolutionising non-invasive surgery.”
Baker RB, Payne C, Yu Y et al. Image-guided Magnetic Thermoseed Navigation and Tumor Ablation Using an MRI System. *Advanced Science* 2 February 2022; doi: 10.1002/advs.202105333
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