With approval from the U.S. Food and Drug Administration (FDA) and a distribution deal for the U.S. and Canada in place, a new surgical option co-invented by a University of Houston physicist is now available to breast cancer patients in the two countries.
The Sentimag technology incorporates a less invasive, more flexible cancer detection alternative for locating early-stage tumors still too small to be felt. With advances in breast cancer screening programs, tumors are now detected much earlier while they are smaller, less defined and more difficult to feel. Roughly 50 percent of all breast tumors are undetectable by touch at the time of diagnosis. These small tumors are often difficult for surgeons to locate during a lumpectomy.
Co-invented by University of Houston (UH) physicist Audrius Brazdeikis and collaborators at the University College of London (UCL), Sentimag is a magnetic surgical guidance probe used in conjunction with nanoparticle tracers and other magnetic devices as a safer and easier method of determining the spread of cancers.
Sentimag is a product of Endomag, which was co-founded in 2007 as a spin-off from UCL and UH by
Brazdeikis, who heads the Biomedical Imaging Group at the Texas Center for Superconductivity at UH, with his colleagues at UCL: physics professor Quentin Pankhurst, director of the UCL Institute of Biomedical Engineering and of the UCL Healthcare Biomagnetics
Laboratory, and systems engineer Simon Hattersley, who brought to the project more than 25 years of experience designing systems, electronics and embedded software for advanced instruments.
Sentimag is able to detect minuscule amounts of magnetic material in the body and thereby guide surgeons performing lumpectomies using proprietary implantable magnetic lesion markers called Magseed, which can be placed by radiologists up to 30 days before a scheduled surgery using ultrasound or radiographic guidance. The device offers greater scheduling flexibility for surgeons and radiologists than is possible using wire-guided localization.
Sentimag’s first commercial introduction in the U.S. will be for use with Magseed to help guide surgeons to cancerous lesions. This Sentimag-Magseed combination provides an alternative to current standards of care for finding breast tumors in advance through lumpectomies that involve surgical procedures with wire needles and potentially harmful radioactive marker seeds.
“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 said in an UH news release.
“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.”
Traditional surgical guide wires, which must be inserted by a radiologist in a separate surgical procedure prior to a patient’s lumpectomy, protrude from the patient’s breast, leading to potential discomfort and restricting the patient to a hospital. Moreover, according to the UH release, the protruding guide wires risk movement before surgery, resulting in follow-up surgery being necessary in up to 55 percent of lumpectomy procedures.
In contrast, Magseed, roughly equivalent in size to a grain of rice, is placed precisely within the tumor, allowing patients to return home while waiting for their lumpectomy procedure, when the Magseed magnetic marker is located using audio-visual cues from the hand-held Sentimag device.
Sentimag can also be used to scan the lymph nodes first in line for a tumor’s metastasizing cancer cells to drain, in a sentinel lymph node biopsy using Sienna+, a tracer capable of producing a transient magnetic response that can be detected in minute quantities by the Sentimag.
Sienna+ is a dark brown aqueous suspension of organically coated, superparamagnetic iron oxide particles that is injected where the lymphatic system’s natural physical action filters out the particles, enabling sentinel nodes to be located using Sentimag. It is a replacement for the radioactive tracer and blue dye currently used in sentinel lymph node biopsies.
The Sentimag-Sienna+ combination, used as part of the sentinel lymph node biopsy procedure for breast cancer staging, completed a multicenter clinical trial with 160 subjects in the U.S. earlier this year at six medical centers in Texas. Sentimag devices and Sienna+ tracer are being used in hospitals in several non-U.S. territories, including Europe, the Caribbean, Hong Kong, Singapore, and Australasia (Australia, New Zealand, and Papua New Guinea).
Sienna+ was the first magnetically detected lymphatic mapping agent to undergo a clinical trial in the U.S. under an Investigational Device Exemption. Results from the trial are being used as the basis of a Premarket Approval (PMA) submission, the FDA’s most stringent type of device marketing application. Brazdeikis estimates it will take 12 to 18 months for Sienna to receive regulatory approval under the demanding PMA guidelines.
A pivotal multicenter clinical trial of the Endomag products in the U.S. was completed in 2015, its findings forming the basis for a PMA submission to the FDA for Sentimag and Magseed this year. The products received FDA 510(k) clearance (a marketing pathway) notification in April, with CE mark approval expected shortly.
Last month, Devicor Medical Products, a division of Leica Biosystems, and Endomagnetics Ltd. announced that Devicor will be the exclusive distributor of Sentimag products in the U.S. and Canada.
“Our partnership with Devicor Medical Products, a leader in breast cancer care, strengthens our ability to support the entire U.S. and Canadian market,” said Endomag CEO Eric Mayes in the UH release. “And our continued research collaboration with Professor Brazdeikis and UH, as well as clinical research collaborations with M.D. Anderson Cancer Center, means that Texas remains essential to our success as we grow our business in the U.S.”