"The goal of our study was to investigate the potential of diffuse optical tomography in the near infrared spectrum with ultrasound localization as a means of differentiating early-stage cancers from benign lesions of the breast," said lead researcher Quing Zhu, Ph.D., professor of bioengineering at the University of Connecticut.
When mammography and ultrasound cannot determine whether a suspicious breast lesion is malignant or benign, physicians typically recommend a needle biopsy to extract samples of the suspicious tissue for laboratory testing. In current clinical practice, 70 to 80 percent of biopsies performed reveal benign lesions, leading to unnecessary cost and anxiety for women.
Diffuse optical tomography is an emerging noninvasive imaging technique that measures light absorption within tissue to quantify blood content (hemoglobin level) and blood oxygen levels. Because cancerous lesions have many more blood vessels than normal tissue, hemoglobin levels can help distinguish malignant from benign lesions.
In Dr. Zhu's study, 178 consecutive women underwent ultrasound-guided diffuse optical tomography (DOT) on a previously identified solid lesion, followed by a biopsy. The study, which included women between the ages of 21 and 89 years, was conducted between 2004 and 2008 at the University of Connecticut Health Center and Hartford Hospital, both in Hartford, Conn.
Performing ultrasound-guided DOT involves the use of a handheld probe consisting of a commercial ultrasound transducer located in the middle and an optical source and detector fibers around the periphery. Once ultrasound locates the lesion, DOT is performed by shining infrared light into the area and measuring light absorption at two optical wavelengths.
"Infrared light penetrates deep into tissue, up to four centimeters," Dr. Zhu said.
Researchers computed total hemoglobin levels from the light absorption measured at two wavelengths and correlated the measurements with biopsy results. Laboratory examination of tissue samples revealed two in situ carcinomas, 35 carcinomas that measured less than two centimeters, 24 carcinomas greater than two centimeters and 114 benign lesions.
"Both maximum and average total hemoglobin levels were significantly higher in the malignant groups than in the benign group," Dr. Zhu said.
The sensitivity and specificity of the technique (92 percent and 93 percent, respectively) were greatest when evaluating cancers less than two centimeters in size.
"Based on our results, we believe that ultrasound-guided diffuse optical tomography holds promise as an adjunct to diagnostic mammography and ultrasound for distinguishing early-stage invasive breast cancers from benign lesions," Dr. Zhu said. "We expect this technology will be used to help radiologists evaluate small to intermediate size lesions that are harder to diagnose with conventional imaging technologies."
Ultrasound and near infrared procedures cost significantly less than magnetic resonance imaging (MRI), another technique used to evaluate suspicious breast lesions that cannot be diagnosed using mammography.
The next step in Dr. Zhu's research, which is supported by grants totaling $1.4 million from the National Institutes of Health with additional $600,000 support from the Donaghue Medical Research Foundation, is to design multi-institution clinical trials for ultrasound-guided DOT.
"Early-Stage Invasive Breast Cancers: Potential Role of Optical Tomography with US Localization in Assisting Diagnosis." Collaborating with Dr. Zhu were Poornima Hegde, M.D., Andrew Ricci, Jr., M.D., Mark Kane, M.D., Edward Cronin, M.D., Yasaman Ardeshirpour, M.S., Chen Xu, Ph.D., Andres Aguirre, M.S., Scott Kurtzman, M.D., Peter Deckers, M.D., and Susan Tannenbaum, M.D.
Radiology is edited by Herbert Y. Kressel, M.D., Harvard Medical School, Boston, Mass., and owned and published by the Radiological Society of North America, Inc. (http://radiology.rsna.org/)
RSNA is an association of more than 44,000 radiologists, radiation oncologists, medical physicists and related scientists committed to excellence in patient care through education and research. The Society is based in Oak Brook, Ill. (RSNA.org)
For patient-friendly information on noninvasive breast imaging procedures, visit RadiologyInfo.org.
Linda Brooks | EurekAlert!
Plasmonic biosensors enable development of new easy-to-use health tests
14.12.2017 | Aalto University
ASU scientists develop new, rapid pipeline for antimicrobials
14.12.2017 | Arizona State University
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
14.12.2017 | Health and Medicine
14.12.2017 | Physics and Astronomy
14.12.2017 | Life Sciences