Photoacoustic CT offers quicker way to scan for breast cancer
Researchers at the California Institute of Technology in Pasadena and Washington University in St. Louis have discovered a way to make scanning breast tissue for cancer a lot easier.
In a single breath-hold, with the woman lying in a prone position without painful compression of the breast, an accurate scan is now available, they say in a paper on their findings, published June 15 in Nature Communications.
According to lead researcher Lihong Wang, professor of medical engineering and electrical engineering at CalTech, the single-breath-hold photoacoustic CT (SBH-PACT) could be available relatively soon. “A company called CalPACT has licensed our IP,” he says. “Depending on the clinical testing and regulatory approval process, commercial availability is expected to take a few years.”
Wang and his fellow researchers hope it won’t be difficult to get health plans to cover the scan. “The commercialized photoacoustic imaging systems are expected to be cheaper than a typical MRI system,” he says. “They are about an order of magnitude of about 10 times faster for breast imaging. The cost per patient visit will be far cheaper consequently.”
About 12 percent of women in the U.S. will develop invasive breast cancer during their lifetimes, according to the American Cancer Society, and the American Society of Clinical Oncology says clinical trials have demonstrated the importance of early detection in improving breast cancer survival.
Currently mammography is “the gold standard used for breast cancer screening,” the paper says, over ultrasound, which is often used as an adjunct to mammography, “but suffers from speckle artifacts and low specificity.”
Magnetic resonance imaging (MRI) is another alternative for screening, “but it poses a large financial burden and requires the use of intravenous contrast agents that can cause allergy, kidney damage and permanent deposition in the central nervous system,” authors of the study say.
“Overall, each modality has notable advantages and limitations,” the researchers say. “Photoacoustic computed tomography (PACT) is a promising complementary modality that overcomes many of these limitations.”
“We are the first to implement breast photoacoustic tomography within a single breath-hold,” Wang says. “The technology became feasible only recently. We are also the first to implement pre-amplification for high-sensitivity imaging.”
According to the paper, the new SBH-PACT can reveal detailed angiographic structures in human breasts and features “a deep penetration depth with high spatial and temporal resolutions.” The PACT can scan the entire breast within less than 15 seconds and provides “a volumetric image that can be reconstructed using a 3D back-projection with negligible breathing-induced motion artifacts.”
The researchers tested the SBH-PACT on women with all breast sizes and skin pigmentations and were able to identify all tumors without resorting to ionizing radiation or exogenous contrast, the researchers say.