Experimental MRI Treatment for Cancer

Scientists at University College London have developed a new cancer therapy. It uses an MRI scanner to guide a magnetic seed through the brain to heat and destroy tumors.

Magnetic Resonance Imaging (MRI) is a medical imaging technique. It uses magnetic fields and radio waves to create detailed images of organs and tissues.

A research paper is published in Advanced Science. It describes the new MRI guided cancer therapy, dubbed MINIMA (minimally invasive image-guided ablation). The paper also describes the first applications of MINIMA in experiments with laboratory mice, which demonstrate the viability of the new therapy.

MINIMA works by first using magnetic propulsion gradients, generated by an MRI scanner, to guide a ferromagnetic thermoseed to a tumor. Then it remotely heats the seed to kill nearby cancer cells. With MINIMA, the MRI scanners that are routinely used in hospitals as diagnostic devices can be also used to deliver cancer therapy.

“MINIMA is a new MRI-guided therapy that has the potential to avoid traditional side effects by precisely treating the tumor without harming healthy tissues,” says research leader Mark Lythgoe in a press release issued by University College London. “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 tumor. Once at the tumor, the seed can then be heated, destroying the cancer cells, while causing limited damage to surrounding healthy tissues."

According to the scientists, the research results establish proof-of-concept for precise and effective treatment of glioblastoma. They also suggest the possibility of treating other cancers, such as prostate, that could benefit from less invasive therapies.

Glioblastoma is the most common form of brain cancer. It is hard to reach with surgery. And the average survival time after surgery is only 12-18 months.

Prostate cancer affects one in eight men. It can be treated more effectively, but with unwanted and debilitating side effects.

The scientists say that MINIMA “has the potential to extend survival and limit damage to adjacent brain tissues” in glioblastoma patients. And it “may allow us to precisely target and destroy prostate tumor tissue, reducing harm to normal cells.”

"We are now able to image and navigate a thermoseed in real-time through the brain using an MRI scanner,” explains Lythgoe.

“As MRI is already used to detect the boundaries of cancers, the seed can be moved precisely to ensure it does not stray into surrounding healthy tissue. As the seed is guided through the tissue it can be heated to destroy the cancer. This combines therapy and diagnosis into a single device, creating a completely new class of imaging therapy."

"In the longer term," concludes Lythgoe, "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, revolutionizing non-invasive surgery."