Navigation Links
Novel technique changes lymph node biopsy, reduces radiaiton exposure
Date:1/13/2009

Information obtained from a new application of photoacoustic tomography (PAT) is worth its weight in gold to breast cancer patients.

For the first time, Lihong Wang, Ph.D., Gene K. Beare Distinguished Professor in the Department of Biomedical Engineering, with a joint appointment in Radiology, and Younan Xia, Ph.D., James M. McKelvey Professor in Biomedical Engineering, with a joint appointment in chemistry in Arts & Sciences, both at Washington University in St. Louis, have used gold nanocages to map sentinel lymph nodes (SLN) in a rat noninvasively using PAT. Wang's lab is the largest PAT lab in the world credited with the invention of super-depth photoacoustic microscopy, and Xia's lab invented the gold nanocages.

Their work can minimize invasive surgical lymph node biopsy procedures to determine if breast cancer has metastasized and reduce the patient's exposure to radioactivity. The nanocages also have the potential to serve as an alternative to chemotherapy to kill targeted cancers by heating them up.

From heat, to expansion, to sound and an image

PAT blends optical and ultrasonic imaging to give high-resolution images of the body that contain information about physiology or tissue function. Molecules already present in the body (endogenous molecules, as opposed to exogenous ones that are from outside the body), such as melanin, hemoglobin, or lipids, can be used as endogenous contrast agents for imaging. When light is shone on the tissue, the contrast agent absorbs the light, converts it to heat, and expands. This expansion is detected as sound and decoded into an image.

"Using pure optical imaging, it is hard to look deep into tissues at high resolution because light scatters. The useful photons run out of juice within 1mm," Wang explained. "PAT improves tissue transparency by 2-3 orders of magnitude because sound scatters less than light. This allows us to see through the tissue by listening to the sound."

Exogenous contrast agents, like the gold nanocages developed by Xia's group, can be used to image parts of the body that even contain endogenous contrast agents. These nanocages are especially attractive because their properties can be tuned to give optimal contrast and gold is non-toxic.

"By controlling the synthesis, we can move the absorption peak for the nanocages to a region that allows them to be imaged deep in tissue. We can also attach biomolecules to the surface of the nanocages so they are targeted to cancer cells," Xia said.

Safe imaging, no radioactivity or surgery

The SLN, the first draining node, is often biopsied in breast cancer patients to determine if the cancer has metastasized. "To find the SLN, doctors inject radioactive particles and a blue dye into the breast. The lymphatic system gobbles up the injected material, treating it as foreign matter and accumulating it in the SLN. The radioactive particles can be detected using a Geiger counter held to the breast to locate the lymph nodes. Then, the doctors surgically open the breast, follow the blue dye, and dissect the SLN," Wang said.

Wang and Xia's technique allows the SLN to be imaged safely without radioactivity or surgery. A piece of tissue can then be removed using a minimally invasive needle biopsy and tested for cancer. "We will convert an invasive surgical procedure into a minimally invasive needle biopsy," Wang said.


'/>"/>

Contact: Lihong Wang
lhwang@wustl.edu
31-493-593-56152
Washington University in St. Louis
Source:Eurekalert

Related biology news :

1. Salk researchers develop novel glioblastoma mouse model
2. Novel technique for fluorescence tomography of tumors in living animals
3. Novel bioreactor enhances interleukin-12 production in genetically modified tobacco plants
4. Stowers Institutes Workman Lab discovers novel histone demethylase protein complex
5. A little wine boosts omega-3 in the body: Researchers find a novel mechanism for a healthier heart
6. A novel target for therapeutics against Staph infection
7. Corn researchers discover novel gene shut-off mechanisms
8. 3-substituted indolones as novel therapeutic compounds for neurodegenerative conditions
9. UT Southwestern researcher awarded Gates Foundation grant for novel vaccine development
10. GEN reports on novel tools for deciphering biological networks
11. Novel publishing approach puts textbook in more hands
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/16/2017)... DALLAS , May 16, 2017   ... for health organizations, and MD EMR Systems ... certified development partner for GE, have established a ... Patient Portal product and the GE Centricity™ products, ... Centricity EMR. These new integrations ...
(Date:4/17/2017)... Florida , April 17, 2017 NXT-ID, ... technology company, announces the filing of its 2016 Annual Report on ... and Exchange Commission. ... on Form 10-K is available in the Investor Relations section of ... as on the SEC,s website at http://www.sec.gov . ...
(Date:4/11/2017)... 11, 2017 No two people are ... the New York University Tandon School of Engineering ... found that partial similarities between prints are common ... mobile phones and other electronic devices can be ... vulnerability lies in the fact that fingerprint-based authentication ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... International research firm Parks Associates announced today that Tom ... 2017 Annual Meeting , October 11 in Scottsdale, Arizona ... and how smart safety and security products impact the competitive landscape. ... Parks Associates: Smart Home Devices: Main Purchase Driver ... "The residential security market has experienced continued growth, and ...
(Date:10/10/2017)... ... October 10, 2017 , ... ... optimization firm for the life sciences and healthcare industries, announces a presentation by ... Francisco. , The presentation, “Automating GxP Validation for Agile Cloud Platforms,” will present ...
(Date:10/9/2017)... , Oct. 9, 2017  BioTech Holdings ... mechanism by which its ProCell stem cell therapy ... limb ischemia.  The Company, demonstrated that treatment with ... of limbs saved as compared to standard bone ... molecule HGF resulted in reduction of therapeutic effect.  ...
(Date:10/9/2017)... ... October 09, 2017 , ... At its national board meeting in ... professor in Harvard University’s Departments of Physics and Astronomy, has been selected for membership ... the winning team for the 2015 Breakthrough Prize in Fundamental physics for the discovery ...
Breaking Biology Technology: