The main method of sentinel lymph node biopsy in use today involves a radioactive tracer and a gamma‐ray detector. While effective, this method comes with significant problems.
First, the method is limited by the supply of a substance called molybdenum‐99, the parent radioisotope to the short‐lived gamma‐emitting technetium-99m used in medical imaging applications. Molybdenum‐99 decays so quickly that it must be supplied to hospital nuclear medicine departments every week, and is made in just a handful of nuclear reactors worldwide. Second, the handling of radioactive materials is subject to stringent regulations, requiring special staff training and segregation of the waste from the operating theatre. Third, the costs in providing and handling the radioactive materials are high. Consequently, in all countries, the majority of women with breast cancer will never be offered sentinel node biopsy based on this method.
In contrast to the radioactive tracer, the Sienna+® device has a shelf life of several years. There are no staff safety issues, and therefore no regulatory burden. It is also less expensive for the hospital than the radioactive tracer, and is therefore accessible to all. The Endomagnetics solution is to use an approved magnetic tracer (Sienna+®), rather than the radioactive tracer and blue dye, in conjunction with an ultrasensitive hand‐held magnetic probe (the SentiMag®) rather than the gamma-ray detector.