In July 2018, the USFDA approved the Magtrace and Sentimag Magnetic Localization System for the guidance of lymph node biopsy in women undergoing a mastectomy. This system employs magnetic detection for identification of sentinel lymph nodes for further surgical removal. The Magtrace particles are injected in the breast tissue and trapped in the lymph nodes. Thereafter the surgeon applies the Sentimag probe to the skin near the tumor sire and detection of magnetic particles within the sentinel lymph node is enabled. Post this, the sentinel node is removed and examined for the presence of cancer cells. The manufacturer of this system, Endomag, claims that the device is less invasive than wire-guided localization systems. It also offers better flexibility in patients, radiologists, and surgeons schedule. The FDA was noted mentioning that the sentinel lymph node biopsies hold vital importance in determining whether the breast cancer has spread, therefore helping the surgeons and physicians in determining the most appropriate treatment course. At present, sentinel lymph node biopsies are performed after injecting radioactive material or blue dye. The approved magnetic localization system will offer mastectomy patients with an alternative to the use of radioactive materials.
Updated data from the SentimagIC trial (NCT02336737) was submitted by Endomag with the primary endpoint being non-inferiority of lymph node detection rate when compared to technetium 99-labeled sulfur colloid radioisotope/isosulfan blue dye control. The first efficacy result of Sentimag IC was first published in 2016, where 160 women with clinically node-negative early stage breast cancer were considered. 37.8% of patients had stage II diseases, and 33.3% and 27.4% of patients had stage I and stage III disease respectively. In this study, a total of 369 lymph nodes were detected, out of which 348 were by Magtrace and compared with 345 for the control. The detection rate per node was 93.5% for the control and 94.3% for Magtrace, therefore showing a difference of 0.8%. Additionally, the per person detection rate was 98.6% with Magtrace and 98% for the control. The concordance rate per patient was 98%. In the patients with at least one metastatic node, the detection rate was 95.5% for Magtrace as well as the control. Moreover, the report also mentioned that Magtrace detected 22 nodes that were missed by control and the control detected 19 nodes missed by Magtrace. The USFDA recommends the system to be used in patients with the metal implant in the axilla or chest or patients with iron overload disease. Sentimag also is not indicated for patients with hypersensitivity to iron oxide or dextran compounds. The Sentimag system had received FDA approval with the Magseed marker technology in 2016 and was approved in the European Union in 2011.
Growing prevalence of breast cancer and higher reporting of late-stage breast cancer in less developed and less aware countries has urged the demand for advanced biopsy techniques for efficient detection of metastasis. Additionally, increasing awareness in the general population and government programmes for early screening of breast cancer also facilitates the demand for minimally invasive biopsy systems. The use of guidance systems in breast biopsy procedures has led to added advantages such as less failure rate, less invasion of the breast tissue, better recuperation through reducing blood loss and infection risk. Guidance modalities such as the Sentimag will undergo further growing demand in the coming years due to their proven efficacy when compared to the use of radiopharmaceuticals. Moreover, the establishment of further clinical evidence for the comparison of the system with other image guidance modalities will improve the stronghold of this modality in the market.