Following cancer with tiny magnets

November 24, 2015 by Aidan Cousins, The Lead
Electron microscopic image of a single human lymphocyte. Credit: Dr. Triche National Cancer Institute

Life-saving surgery and treatments rely on doctors being able to accurately track the spread of cancers.

A new device that uses iron particles and a magnetic probe will allow clinicians to narrow down exactly which tumours spread to.

Developed by Aidan Cousins with colleagues at the University of South Australia, the novel approach is more sensitive and safer than existing methods for monitoring cancer.

"Pre-clinical trials of our approach suggest it gives a very clear picture of where tumours are most likely to spread," Aidan explained.

"It will allow subsequent surgery and treatment options to be refined for better standards of care and improved prognosis."

The technique involves injecting biodegradable at the primary site of a tumour, from where – as part of their normal surveillance activities – cells of the immune system transport them to the draining lymph nodes.

"The first place primary cancers typically spread to is the lymph node that taps directly from that site," said Aidan.

"The particles accumulate in the same place, and we use the probe to detect their magnetic properties as soon as 20 minutes after injection."

The network of lymphatic vessels and nodes that drain our body's organs are notoriously difficult to map, being very fine and transparent.

Currently the only way spread of cancer from a primary site to lymph nodes can be tracked is with a radioactive tracer. The material is injected into the patient, and preferentially accumulates wherever tumour cells are multiplying. So-called 'hot spots' can then be identified using a radiation-detecting probe.

"This approach has a resolution of around 20mm, which means that sometimes a cancer-free lymph node is removed along with a 'hot' one," said Aidan.

"In addition, it requires the patient being exposed to a small dose of radioactive material."

By comparison, Aidan's magnetic technique offers 5 times better accuracy and is logistically simpler and safer for both patient and medical staff.

"The most exciting aspect of this technology is the spatial resolution," explained Aidan.

"At the moment, we can distinguish between a positive and a negative lymph node even if they're in direct contact."

This means that patients would be able to keep their healthy lymph nodes, and have cancerous ones removed to prevent further spread.

Aidan and his colleagues expect to improve this sensitivity even further in the near future, with extra refinements of the approach already in development.

"Our approach may be particularly suited to identifying the spread of cancers from the head and neck, and also from the , where draining lymph nodes can be located very close together," Aidan said.

Dr Melissa Moore is a Medical Oncologist at St Vincent's Hospital in Melbourne, Victoria, and specialises primarily in cancers of the breast, lung and upper gastrointestinal tract. She said accurate monitoring of cancer spread is a critical factor in determining the best therapies for patients.

"The presence of cancer cells in the draining lymph nodes is a main factor in determining risk of tumour recurrence," said Dr Moore.

"We use information about the nodal positivity to guide us in determining the best treatments for patients, including surgery but also chemotherapy and hormone therapy."

"In this way, tools that enable better tracking of cancer spread will have a clinical impact," she said.

With the design of the magnetic probe patented, Aidan and his colleagues have recently published a report on a successful preclinical trial.

The scientists are now working with collaborators to progress the technology towards clinical testing.

Explore further: Researchers develop 'killer cells' to destroy cancer in lymph nodes

More information: A. Cousins et al. Novel Handheld Magnetometer Probe Based on Magnetic Tunnelling Junction Sensors for Intraoperative Sentinel Lymph Node Identification, Scientific Reports (2015). DOI: 10.1038/srep10842

Related Stories

Researchers develop 'killer cells' to destroy cancer in lymph nodes

November 12, 2015
Cornell biomedical engineers have developed specialized white blood cells - dubbed "super natural killer cells" - that seek out cancer cells in lymph nodes with only one purpose: destroy them. This breakthrough halts the ...

Which breast cancer patients need lymph nodes removed? Ultrasound narrows it down

February 2, 2015
Which breast cancer patients need to have underarm lymph nodes removed? Mayo Clinic-led research is narrowing it down. A new study finds that not all women with lymph node-positive breast cancer treated with chemotherapy ...

Less invasive surgery detects residual breast cancer in lymph nodes after chemotherapy

December 5, 2012
Most patients whose breast cancer has spread to their lymph nodes have most of the lymph nodes in their armpit area removed after chemotherapy to see if any cancer remains. A study conducted through the American College of ...

Development of new blood vessels not essential to growth of lymph node metastases

June 25, 2015
While the use of antiangiogenesis drugs that block the growth of new blood vessels can improve the treatment of some cancers, clinical trials of their ability to prevent the development of new metastases have failed. Now ...

Lymph nodes signal more aggressive thyroid cancer even in young patients

June 16, 2015
Patients older than age 45 with thyroid cancer that has spread to neck lymph nodes have long been considered at higher risk of dying, but the same has not been true for younger patients.

Radiation-free method to track suspicious lymph nodes in case of cancer

August 29, 2014
Researchers at the UT Research Institute MIRA have developed a new method for tracing the sentinel lymph node, the node by which you can tell whether a patient's cancer has spread. Martijn Visscher demonstrated that you can ...

Recommended for you

Testing fluorescent tracers used to help surgeons determine edges of breast cancer tumors

September 20, 2018
A team of researchers with members from institutions in The Netherlands and China has conducted a test of fluorescent tracers meant to aid surgeons performing tumor removal in breast cancer patients. In their paper published ...

Understanding epilepsy in pediatric tumors

September 20, 2018
Pediatric brain tumors are characterized by frequent complications due to intractable epilepsy compared to adult brain tumors. However, the genetic cause of refractory epilepsy in pediatric brain cancer has not been elucidated ...

Researchers find adult stem cell characteristics in aggressive cancers from different tissues

September 19, 2018
UCLA researchers have discovered genetic similarities between the adult stem cells responsible for maintaining and repairing epithelial tissues—which line all of the organs and cavities inside the body—and the cells that ...

Ketogenic diet reduces body fat in women with ovarian or endometrial cancer

September 19, 2018
Women with ovarian or endometrial cancer who followed the ketogenic diet for 12 weeks lost more body fat and had lower insulin levels compared to those who followed the low-fat diet recommended by the American Cancer Society, ...

Could the zika virus fight the brain cancer that killed john McCain?

September 18, 2018
(HealthDay)—Preliminary research in mice suggests that the Zika virus might be turned from foe into friend—enlisted to curb deadly glioblastoma brain tumors.

Eating foods with low nutritional quality ratings linked to cancer risk in large European cohort

September 18, 2018
The consumption of foods with higher scores on the British Food Standards Agency nutrient profiling system (FSAm-NPS), reflecting a lower nutritional quality, is associated with an increased risk of developing cancer, according ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.