Study: New marker may better locate early breast cancers
A multidisciplinary team has developed a new microscopic hollow particle that can functions as an color Doppler ultrasound contrast agent for breast imaging, which could help physicians better localize breast cancers prior to surgery, according to an article published in the September edition of MedChemComm.
Current surgical protocols for removal of early stage cancer require placement of wire in the tumor under x-ray or ultrasound guidance to mark the tumor, a procedure associated with a 20 to 50 percent rate of positive margins and a high rate of second operations, according to William Trogler, MD, professor of surgery, University of California, San Diego. Brachytherapy can reduce the number of second surgeries, but is associated with other drawbacks including exposure to ionizing radiation, difficulty handling multiple tumor foci and lack of 3D imaging tools in the operating room.
Ultrasound offers a useful intraoperative technique for localization and removal of tumors, but its effectiveness is compromised by limited imaging contrast, shared Trogler.
The uncoated silica shells may offer several advantages for breast imaging. “The immobility of the uncoated silica shells in tissue makes this platform amenable to be used as an adjunct or as a possible replacement to needle localization of nonpalpable tumors to mark them for surgical removal,” wrote Trogler.
The gas-filled microbubbles adhere to human breast tissue for days, explained the researchers. If the marker were placed in early stage cancer prior to surgery, it might help surgeons better visualize cancers and remove all cancer in one procedure, continued Trogler.
The final advantage of the particle is its size--two micrometers, allowing precise injection days before surgery. Surgeons would employ intraoperative ultrasound to reveal the bubbles, and cancerous tissue, in three dimensions.
“By outlining the tumor more completely in multiple directions, the particles could potentially help surgeons remove non-palpable tumors in a single operation,” said Sarah Blair, MD, a surgeon at University of California, San Diego. “They will definitely make the operation more comfortable for the patient.”
Current research established the feasibility of the technology in tissue samples. Tests in animal models are underway and toxicology studies are required prior to human testing.