24-05-2022 | | By Robin Mitchell
A new product designed to help doctors track cancer spread may soon be used by the NHS for breast cancer patients. What challenges do radioisotope tracers present, how can Magtrace be used to track cancer spread, and does this demonstrate a new era for safer cancer treatments?
When treating cancer, one of the most important tasks is identifying exactly where cancer has spread as even trace amounts of cancer cells make their way into the bloodstream and find a new home somewhere else. For example, a tumour in the lungs can see some cells break away, enter the bloodstream, and then attach themselves to the bone. While these cells are still lung cells, they metastasise into other organs and disrupt surrounding tissue.
One saving grace of such cancer cells is that they are all identical and behave in the same way. As such, researchers can create special tracer compounds that only bind to a specific type of cell and injecting such a tracer into the body will attach itself to all cells, including those that have metastasised. If such a tracer is combined with a radioisotope, doctors can use the radioactive signature of the attached tracer to generate an internal image of the body showing cancer cells around the body.
Radioisotopes have proven to be an invaluable tool in cancer diagnosis, and as such, it should be clearly stated that even though they do have disadvantages (which will be shortly covered), they have saved countless lives and deserve to be given the utmost respect.
However, radioisotopes do indeed have some disadvantages that make their use challenging at times. The first and most obvious is that they are highly radioactive, and this radioactivity can see them damage other cells (even potentially create new cancers). Their high radioactivity comes from the need for a short-lived compound whose radioactivity will quickly diminish, but this also means that their short half-life makes them potent emitters.
This radioactivity also requires patients to be isolated from others, and the use of short-lived radioisotopes means that the tracer needs shielded storage and must be used shortly after manufacture. Thus, radioisotopes are not found in all hospitals, and only those with clear logistical planning with isotope manufacturers can use such compounds. This restricts patient location and diagnoses options depending on location.
A new report by the NHS shows how the health organisation is planning to use a new compound to improve breast cancer diagnoses that does away with the need for radioactive isotopes, storage, and patient isolation. The new compound, called Magtrace, comprises a magnetic liquid that can be directly injected into tissue surrounding a known cancer growth. The liquid then travels around the lymphatic system, which is most likely taken by any stray cancer cells.
This highly magnetic liquid is then detected using an ultrasensitive metal detector that costs around £25K (the tracing fluid itself is around £250 per bottle). While this may seem expensive, it is very cheap considering the medical nature of the equipment and its ability to find new cancers without the need for radioisotopes.
Following the magnetic presence with audible tones, areas that are likely to contain cancer can be identified, allowing doctors to take targeted biopsies. Furthermore, the tracer stains lymph nodes dark brown that can easily be identified by surgeons, and this enables them to better target tissue removal. Thus, the non-toxic, non-radioactive compound presents doctors with a new potential tracing method that doesn’t rely on dangerous compounds that would be accessible in most clinics.
The use of electronic equipment to identify potential areas of cancer using non-radioactive compounds could usher in a new era for cancer treatment. While it should be noted that the Magtrace compound doesn’t detect cancer initially (it shows where it could spread), it greatly aids in those looking to see if cancer has spread and where best to perform biopsies. Other detection and imaging methods do exist (such as CAT scans and MRI), but these are generally very expensive and impractical to provide for patients relying on a government-run organisation.
Looking forward to the future, it may be possible to combine the use of magnetic tracers with AI and sensors to create magnetic images showing the path of cancer spread. This may even be taken further with the use of smaller detectors for use at home and an ingestible pill that can attach itself to areas of concern, and this may then allow patients to partly self-diagnose before seeking a professional.