Navigation Links
New probe provides vital assist in brain cancer surgery

A new probe developed collaboratively at Norris Cotton Cancer Center and Dartmouth College's Thayer School of Engineering uses an innovative fluorescence-reading technology to help brain surgeons distinguish cancerous tissue from normal tissue. The probe tool, now already in use at the Cancer Center for brain surgery, may one day be used for surgeries for a variety of cancers.

Performing surgery to remove a brain tumor requires surgeons to walk a very fine line. If they leave tumor tissue behind, the tumor is likely to regrow; if they cut out too much normal tissue, they could cause permanent brain damage.

"Primary brain tumors look just like brain tissue," says Keith Paulsen, PhD, a professor of biomedical engineering at Thayer School of Engineering and a member of the Cancer Imaging and Radiobiology Research Program at Norris Cotton Cancer Center. "But if you look at them under a particular kind of light, they look much different."

To improve their ability to differentiate between tumor cells and healthy tissue, surgeons can have patients take an oral dose of the chemical 5-aminolevulinic acid (ALA). An enzyme metabolizes ALA, producing the fluorescent protein protoporphyrin IX (PpIX). Tumor cells have a higher metabolic rate than normal cells, so they accumulate more PpIXand therefore fluoresce, or "glow," when exposed to blue light.

But this method was thought to be not sensitive enough to highlight brain tumors that are less metabolically active, like low-grade gliomas. To address this problem, MD-PhD student Pablo Valdes, PhD, and his research mentorsDavid Roberts, MD, the chief of neurosurgery at Dartmouth-Hitchcock Medical Center, and Dr. Paulsenused a probe (which they helped develop) that combines violet-blue and white light to simultaneously analyze both the concentration of PpIX and four other tumor biomarkers: PpIX breakdown products, oxygen saturation, hemoglobin concentration, and irregularity of cell shape and size. The probe reads how light travels when it hits the tissue, sends this data to a computer, runs it through an algorithm, and produces a straightforward answer as to whether the tissue is cancerous.

"Our big discovery is that we can use the probe's reading of the fluorescing agent to measure the existence of a low-grade tumor in tissue," says Dr. Paulsen. "The probe is basically an enabling technology to show that information to the surgeon a visual aid."

He says that when they first saw the results of using their fluorescing agent and probe on low-grade brain tumors, it was "jaw-dropping. The tumor glowed like lava."

The Thayer/Norris Cotton Cancer Center/Dartmouth-Hitchcock Medical Center team, which has been working on the brain probe for about six years in collaboration with researchers from the University of Toronto, built on research that was originally conducted in Germany about 15 years ago. But the German research did not focus on low-grade tumors. The assumption, Dr. Paulsen says, was that, due to the blood-brain barrier, low-grade tumors did not have enough PplX and therefore would not fluoresce.

In a pilot study, Roberts operated on 10 patients with gliomas. He used a microscope throughout the surgery to see the fluorescence and used the hand-held probe to evaluate sections of the tissue where the fluorescence was not definitive. After the surgeries were complete, a pathologist evaluated how accurately the probe had identified tumor tissue.

The results, published in the Journal of Biomedical Optics, are striking. Diagnoses based on fluorescence only had an accuracy of 64 percent. But when Roberts used the probe, the accuracy increased to 94 percent, meaning that Roberts was much more successful in differentiating between tumor tissue and normal tissue. Although the study was small, it introduces a promising method to help surgeons remove only what they want and nothing more.

Dr. Paulsen says that a protocol is in place for a similar study on lung cancer tumors. He thinks the brain probe may have applications for other cancers as well, but for now the research will have to proceed one cancer type at a time.


Contact: Donna Dubuc
Dartmouth-Hitchcock Medical Center

Related medicine news :

1. Scientists Probe Diversity of Human Bodys Microbes
2. Molecular probes identify changes in fibronectin that may lead to disease
3. Study Probes How Sad Movies Make Viewers Happy
4. Newer hip reconstruction technique provides good outcomes for athletes
5. Vertebroplasty reportedly provides better pain relief and function
6. OnPage Provides Secure, Rapid Response at New England’s Largest Catholic Hospital
7. Better Health Osteopathic & Integrative Medicine Centre Provides Health Education and Care
8. Now Provides Competitive Car Insurance Quotes To Kansas Drivers
9. Now Provides Competitive Car Insurance Quotes To Arkansas Drivers
10. Senior Alert Button RA911 by Rescue Alert Provides Emergency Assistance Away From Home
11. Now Provides Competitive Car Insurance Quotes To Kentucky Drivers
Post Your Comments:
(Date:11/25/2015)... ... November 25, 2015 , ... Brillianteen, ... friendships, and learning in its 65th Anniversary Brillianteen Revue, scheduled for March 4-6, ... , For 65 years, Brillianteen has been a treasured tradition for numerous families ...
(Date:11/25/2015)... ... November 25, 2015 , ... Castlewood Treatment Center for Eating ... disorders as a result of the $20,000 raised at the center’s recent ... Golf Club in Eureka, will help individuals who otherwise might not seek treatment ...
(Date:11/25/2015)... ... November 25, 2015 , ... An unlikely ... resulting in a way for homeless people to have a more dignified and ... new initiative whereby they are repurposing plastic bags into sleeping mats for the ...
(Date:11/25/2015)... ... November 25, 2015 , ... Students and parents have something to be thankful ... Create Real Impact awards. California Casualty is proud to support the contest ... distracted and reckless driving, the number one killer of young drivers. , Almost ...
(Date:11/24/2015)... , ... November 24, 2015 , ... Dr. Todd S. ... offer laser services to many of his patients. Dr. Afferica now uses the BIOLASE ... reduce the amount of time the doctor uses other traditional cutting tools, such as ...
Breaking Medicine News(10 mins):
(Date:11/25/2015)... , Nov. 25, 2015  ARKRAY USA ... continues to provide evidence demonstrating the accuracy of its ... Congress on Insulin Resistance, Diabetes and Cardiovascular Disease in ... both the Company,s GLUCOCARD ® 01 meter and ... accuracy requirements. The ability to accurately measure glucose levels ...
(Date:11/25/2015)... 2015  Trovagene, Inc. (NASDAQ: TROV ), a ... Executive Officer Antonius Schuh, Ph.D., is scheduled to present ... Piper Jaffray Healthcare Conference. th Annual ... Hotel in New York on ... Schuh will be available for one-on-one meetings during the ...
(Date:11/25/2015)... , Nov. 25, 2015 USP ... hazardous drug preparations (e.g. pharmacists, pharmacy technicians, nurses, ... veterinary technicians). The chapter also covers all entities ... (e.g., pharmacies, hospitals, other healthcare institutions, patient treatment ... --> --> What ...
Breaking Medicine Technology: