New technology allows surgeons to locate impalpable breast tumors
HOUSTON, USA: Researchers from the University of Houston (UH) and the University College London (UCL) have developed a new diagnostic system for breast cancer surgery that eliminates exposure to radioactive materials and offers a less invasive, more flexible alternative for cancer detection. The Sentimag instrument enables surgeons to locate early-stage tumors that cannot yet be perceived by palpation. It received Food and Drug Administration approval in April and a distribution deal this month.
Co-invented by UH physicist Dr. Audrius Brazdeikis and his collaborators at UCL, Sentimag is a magnetic surgical guidance probe used with nanoparticle tracers and other magnetic devices to more safely and easily determine the spread of cancer. The device can be used together with an implantable magnetic lesion marker called Magseed that guides surgeons to cancerous lesions. The combination of Sentimag and Magseed can replace procedures involving surgical wire needles and radioactive seeds, which are the two standards of care currently in practice for finding a breast tumor in advance of a lumpectomy.
Having received clearance from the FDA in April, the Sentimag and Magseed breast cancer diagnostic system can now be marketed stateside. Through a distribution deal unveiled this month between Devicor Medical Products and Endomag, a UH spinoff medical device company co-founded by Brazdeikis, the technology will be immediately available for use in the U.S. Devicor Medical Products, part of Leica Biosystems, will be the exclusive distributor of Sentimag in the U.S. and Canada.
As breast cancer screening programs have advanced, tumors are now detected at a much earlier stage. However, they are therefore also smaller, less defined and more difficult to perceive by palpation. In fact, 50 percent of all breast tumors cannot be felt at diagnosis. These small and often impalpable tumors are difficult for surgeons to locate during a lumpectomy.
“Magseed is designed to guide surgeons using Sentimag to locate impalpable tumors for biopsy and has many advantages over wire and radioactive seed localization,” Brazdeikis stated. “Radiologists can place the Magseed magnetic markers up to 30 days in advance of surgery using X-ray or ultrasound guidance. This offers scheduling flexibility for surgeons and radiologists, as well as for patients, compared to wire-guided localization,” he added.
Traditional guide wires, which are inserted by a radiologist in a separate procedure prior to the lumpectomy, protrude from the patient’s breast, leading to potential discomfort and restricting the patient to the hospital. More critically, the protruding guide wires risk movement prior to surgery, requiring follow-up surgery in up to 55 percent of lumpectomy procedures. In contrast, Magseed is similar in size to a grain of rice and placed within the tumor, allowing patients to return home ahead of their operations. During the lumpectomy, the Magseed magnetic marker is located using audiovisual cues from the Sentimag device.
Brazdeikis, who heads the Biomedical Imaging group at the Texas Center for Superconductivity at UH, co-founded Endomag with his colleagues at UCL, Professor of Physics Quentin Pankhurst and systems engineer Simon Hattersley. Prior to its approval for use in the U.S., Sentimag received the European conformity (CE) marking in 2010 for sale in Europe and has been used in more than 14,000 breast cancer procedures across Europe with another Endomag product, the Sienna+ magnetic nanoparticle tracer. The tracer is applied in sentinel lymph node biopsies to locate the first lymph node to which a tumor’s metastasizing cancer cells drain.