Polarized filter may reduce unnecessary cervical biopsies and surgeries
Dr. Daron G. Ferris at Georgia Health Sciences University is leading a National Cancer Institute-funded study to determine whether a polarized filter can help reduce unnecessary cervical biopsies and surgeries. Credit: Phil Jones, GHSU Photographer
The same filtered light that enables sunglasses to reduce glare may improve a physician's ability to detect early signs of cervical cancer, reducing unnecessary biopsies and surgery.
Polarized light is more focused than traditional radial light which scatters in all directions, said Dr. Daron G. Ferris, colposcopist, family medicine physician and Director of the Gynecologic Cancer Prevention Center at Georgia Health Sciences University.
When a woman gets an abnormal Pap smear, it's often followed by a colposcopic exam where radial light and magnification are used to view the cervix then biopsies are performed on suspicious areas.
A National Cancer Institute-funded study is helping determine whether also taking a look through a polarized filter improves the ability to detect precancerous changes, enhancing efficacy while reducing needless biopsies and the discomfort and cost that may result.
"Using both types of light to examine the cervix may give us additional perspective so we can find more disease and avoid treating something that does not need it," Ferris said.
In the study of 300 women age 18 and older, Ferris is first using the standard approach, including marking suspicious areas, then taking another look with the polarized filter to see how the findings correlate before doing a biopsy. "If we use polarized light, how does that change what we can see?" he said.
The approach might be most effective in young women where normal immature cell types in the cervix are more difficult to discriminate from neoplastic cells. This extremely thin skin is an easy target for infection by human papillomavirus, the primary cause of cervical cancer, Ferris said.
"If polarized light eliminates cases where it's not clear whether the area is worrisome or not, that is going to reduce the number of biopsies," Ferris said. "We want to see if it adds value." And the confusion may not end with the biopsy: sometimes biopsies also are misinterpreted, leading to unnecessary surgery.
Just as polarized glasses help fisherman see fish swimming below the water surface, polarized light, which focuses its energy in one direction, also enables physicians to better see beneath the surface of the cervix for telltale signs of trouble. In suspicious areas, blood vessels tend to be more dilated, farther apart and more randomly distributed. "We normally look at superficial blood vessels, but this takes us to a level we have not been able to see," said Ferris of the ability to see 1 millimeter (.04 inches) below the surface with the polarized filter.
Ferris got the idea that polarized light might enhance colposcopy from studying hundreds of images of the cervix taken for fluorescent spectroscopy, which uses a polarized filter to reduce the reflection created by fluorescent light. "I started seeing things that I had never seen before and it struck me that it might be of use in colposcopy," said Ferris, who was part of a study trying to teach computers to recognize cervical lesions.
Dermatologists have been using polarized filters for years to look at external skin surfaces. Some colposcopy machines, where the cervix is viewed through a monitor rather than a microscope, already are equipped with a polarized light filter to reduce glare. Most colposcopes now have green filters that block red light so blood vessels appear black and are easier to detect.
Studies have questioned colposcopy's accuracy. Two National Cancer Institute researchers concluded in a 2006 article in the American Journal of Obstetrics and Gynecology that colposcopy was missing cancerous lesions and efforts to improve accuracy were needed.
The bagel-shaped cervix is the door to the uterus, which produces mucus and helps keep a fetus in the womb during pregnancy. Biopsies of the thin-skinned organ can result in bleeding and increase infection risk.
Journal reference: American Journal of Obstetrics and Gynecology
Provided by Georgia Health Sciences University
- New HPV vaccine under study Nov 19, 2007 | not rated yet | 0
- Study: Squid are masters of disguise Sep 25, 2006 | not rated yet | 0
- Student Develops First Polarized LED Mar 03, 2008 | not rated yet | 0
- Light vortex: Circularly polarized luminescence from a stirred and gelled solution of dye Oct 26, 2011 | not rated yet | 0
- Beetles stand out using Avatar tech Apr 14, 2010 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Classical and Quantum Mechanics via Lie algebras
Apr 15, 2011 I'd like to open a discussion thread for version 2 of the draft of my book ''Classical and Quantum Mechanics via Lie algebras'', available online at http://lanl.arxiv.org/abs/0810.1019 , and for the...
- More from Physics Forums - Independent Research
More news stories
High blood glucose is associated with poor outcomes in hospitalized patients, and use of intensive insulin therapy (IIT) to control hyperglycemia is a common practice in hospitals. But the recent evidence does not show a ...
Other May 24, 2013 | 4 / 5 (1) | 0
Two out of five medical students have an unconscious bias against obese people, according to a new study by researchers at Wake Forest Baptist Medical Center. The study is published online ahead of print in the Journal of ...
Other May 23, 2013 | not rated yet | 0
Nanyang Technological University's (NTU) new medical school will be pioneering the use of plastinated bodies for medical education in Singapore.
Other May 23, 2013 | not rated yet | 0
A 2012 survey of internal medicine residents at Massachusetts General Hospital (MGH) – one of the nation's leading teaching hospitals – found that more than half rated the training they had received in addiction and other ...
Other May 22, 2013 | 5 / 5 (1) | 0
Early use of tracheostomy for mechanically ventilated patients not associated with improved survival
For critically ill patients receiving mechanical ventilation, early tracheostomy (within the first 4 days after admission) was not associated with an improvement in the risk of death within 30 days compared to patients who ...
Other May 21, 2013 | not rated yet | 0
(Medical Xpress)—A new study by researchers in the US has shown that an ancient virus can be modified to help in the fight against the simian immunodeficiency virus SIV, which is the equivalent in monkeys ...
17 hours ago | 5 / 5 (3) | 0 |
Two mutations central to the development of infantile myofibromatosis (IM)—a disorder characterized by multiple tumors involving the skin, bone, and soft tissue—may provide new therapeutic targets, according to researchers ...
11 hours ago | 3 / 5 (2) | 0 |
Women at a particular stage in their monthly menstrual cycle may be more vulnerable to some of the psychological side-effects associated with stressful experiences, according to a study from UCL.
14 hours ago | 3.7 / 5 (3) | 0 |
Biological processes are generally based on events at the molecular and cellular level. To understand what happens in the course of infections, diseases or normal bodily functions, scientists would need to ...
14 hours ago | 5 / 5 (4) | 0 |
How can healthy people who hear voices help schizophrenics? Finding the answer for this is at the centre of research conducted at the University of Bergen.
17 hours ago | 4 / 5 (2) | 2
(Medical Xpress)—The way Alzheimer's disease is portrayed by advocacy groups and the media is having undue influence on the euthanasia debate, according to a Deakin University nursing ethics professor.
18 hours ago | not rated yet | 2