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Baylor St. Luke’s Medical Center is the first hospital in the Southern U.S. to use non-radioactive guidance system to locate and remove tumors in patients with invasive breast cancer

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HOUSTON (Oct. 24, 2019) – Dr. Alastair Thompson and Dr. Stacey Carter, breast surgeons at Baylor St Luke’s Medical Center, are the first breast surgeons in the Southern United States to use the Sentimag Magnetic Localization System with both the Magseed technology and the newly FDA-approved Magtrace liquid tracer during a surgical treatment for invasive breast cancer.  

The Magseed is a small metal seed the size of the tip of a pen that is used to mark and remove small tumors that are difficult for the surgeon to feel. The seed is placed directly into the center of the tumor any time before surgery under mammogram or ultrasound guidance. This enables the surgeon to accurately locate the center of the tumor and ensure it is removed in one piece while preserving as much healthy tissue. The Magseed replaces the need for a wire localization technique, which can be painful and uncomfortable for the patient.

“The Magseed technology is an incredible guidance system that takes me to a relatively small area of the breast that needs to come out while avoiding excessive tissue being removed and avoiding a mastectomy,” said Thompson, who also is section chief and professor of breast surgery at Baylor College of Medicine. “Not having to have a wire placed in the breast beforehand while the patient is awake makes the experience more comfortable while giving even better technical help to me as a surgeon.”

“This procedure is really transformational for the patient because it allows us to do a small day case, fine-tuned delicate surgery rather that doing a big operation,” he said. “Additionally, the tumor with the seed in it and the surrounding tissue get looked at immediately by our pathologists to give an assessment while the patient is still asleep. It helps us get away from the 1 in every 3 patients across the United States that has to undergo a second operation for a re-excision.”

Patients undergoing a lumpectomy often need to have their lymph nodes removed to determine whether the cancer has spread beyond the initial tumor into the lymph nodes. The Magtrace iron-oxide solution can be injected prior to a sentinel lymph node biopsy while the patient is asleep to help surgeons identify the sentinel nodes with the highest reading.

Using the system’s handheld wand and base unit display, surgeons are able to find the sentinel lymph nodes for surgical removal based on the strength of the magnetic signal. The magnetic Magtrace replaces the need for the old method that typically involves the injection of a radioactive substance and a blue dye agent, which can stain the skin near the injection site and cause allergic reactions.

Carter is an assistant professor of surgery at Baylor College of Medicine. Thompson and Carter are members of the Lester and Sue Smith Breast Center, part of the Dan L Duncan Comprehensive Cancer Center at Baylor St. Luke’s Medical Center, which was ranked among the 50 top cancer hospital programs in the country by U.S. News and World Report.

About Baylor St. Luke’s Medical Center

Baylor St. Luke’s Medical Center is an 881-bed quaternary care academic medical center that is a joint venture between Baylor College of Medicine and St. Luke’s Health. Located in the Texas Medical Center, the hospital is the home of the Texas Heart® Institute, a cardiovascular research and education institution founded in 1962 by Denton A. Cooley, MD. The hospital was the first facility in Texas and the Southwest designated a Magnet® hospital for Nursing Excellence by the American Nurses Credentialing Center, receiving the award five consecutive times. Baylor St. Luke’s also has three community emergency centers offering adult and pediatric care for the Greater Houston area.

About the CHI Texas Division

The CHI Texas Division, a member of Catholic Health Initiatives (CHI), is comprised of three markets―in Houston, St. Luke’s Health (St. Luke’s) is home to eight hospitals, eight emergency centers, Diagnostic & Treatment Center, Radiation & CyberKnife Center, and numerous Baylor St. Luke’s Medical Group locations throughout Greater Houston; St. Luke’s Health Memorial (three hospitals and a long-term acute care facility in East Texas); and St. Joseph Health (five hospitals and several St. Joseph Medical Group locations across Brazos Valley). In addition, St. Luke’s flagship hospital, Baylor St. Luke’s Medical Center in the Texas Medical Center, is a joint venture with Baylor College of Medicine. Together, St. Luke’s and Baylor College of Medicine are transforming healthcare delivery with a mission to usher in a new era of healthcare to create healthier communities. For more information, visit

About Endomag

Endomag is the global technology company that believes everyone deserves a better standard of cancer care. Many of the world’s leading physicians and hospitals use the company’s technologies to help women with breast cancer avoid surgery when it isn’t needed, and experience better outcomes when it is. The Sentimag® probe works like a metal detector, which when placed near the skin’s surface can detect Endomag’s magnetic seed (Magseed®) or liquid tracer (Magtrace®), used in tissue localisation and sentinel node biopsy procedures, respectively. To this day the Sentimag® system has been used in over 70,000 breast cancer procedures at over 400 hospitals in more than 30 countries.  Endomag is a global company headquartered in Cambridge, UK with an office in Austin, Texas. To date, the company has helped tens of thousands of women around the world access more precise and less invasive breast cancer care. To learn more visit:

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