Navigation Links
Novel technique changes lymph node biopsy, reduces radiation 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. Novel technique changes lymph node biopsy, reduces radiaiton exposure
2. Salk researchers develop novel glioblastoma mouse model
3. Novel technique for fluorescence tomography of tumors in living animals
4. Novel bioreactor enhances interleukin-12 production in genetically modified tobacco plants
5. Stowers Institutes Workman Lab discovers novel histone demethylase protein complex
6. A little wine boosts omega-3 in the body: Researchers find a novel mechanism for a healthier heart
7. A novel target for therapeutics against Staph infection
8. Corn researchers discover novel gene shut-off mechanisms
9. 3-substituted indolones as novel therapeutic compounds for neurodegenerative conditions
10. UT Southwestern researcher awarded Gates Foundation grant for novel vaccine development
11. GEN reports on novel tools for deciphering biological networks
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/2/2016)... 2, 2016   Parabon NanoLabs (Parabon) ... Army Research Office and the Defense Forensics and ... of the company,s Snapshot Kinship Inference ... more generally, defense-related DNA forensics.  Although Snapshot is ... appearance and ancestry from DNA evidence), it also ...
(Date:2/1/2016)... , Feb. 1, 2016  Today, the first ... (AHA) announced plans to develop a first of its ... power of IBM Watson. In the first application of ... IBM (NYSE: IBM ), and Welltok will create ... health assessments with cognitive analytics, delivered on Welltok,s health ...
(Date:1/27/2016)... Jan. 27, 2016  Rite Track, Inc. a leading ... West Chester, Ohio announced today the ... staff, based in Austin, Texas , ... to provide modifications, installations and technical support offerings for ... of PLUS, commented, "PLUS has provided world class service ...
Breaking Biology News(10 mins):
(Date:2/5/2016)... -- On Thursday, February 11, 2-1-1 San Diego ... and disaster services, and the Community Information Exchange ... coordination and service delivery for the community to better ... better connect service providers to the information they can ... has handled more than 2.5 million connections ...
(Date:2/4/2016)... - New FDA action date of July ... action date of July 22, 2016   --> ... 22, 2016   - Lifitegrast has the ... for the treatment of signs and symptoms of dry eye disease ... to be the only product approved in the U.S. in the past decade indicated for ...
(Date:2/4/2016)... 4, 2016 Beike Biotechnology, the ... attended a ceremony in late 2015 to mark their ... in 2016. --> --> ... for Personalized Cell Therapy" was hosted by the Shenzhen ... both subsidiaries of Beike Biotechnology Co., Ltd. ...
(Date:2/4/2016)... -- ContraVir Pharmaceuticals, Inc. (NASDAQ: CTRV ), a ... targeted antiviral therapies, announced today that it will present ... held February 8-9, 2016, at the Waldorf Astoria New ... Healthcare Conference, taking place in New York ... Sapirstein , Chief Executive Officer of ContraVir, will provide ...
Breaking Biology Technology: