Faster Diagnosis of Deadly Melanoma Skin Cancers May
Come From Infrared System
Doctors need to identify a mole that may be
melanoma at an early, treatable stage to save the lives of thousands of
senior citizens
Johns Hopkins researchers are testing an
infrared scanning system to detect melanoma.
Feb. 26, 2010 – There were 8,650 deaths from
melanoma skin cancers last year, with male senior citizens the most
common victim. It is assumed that many lives can be saved if the cancer
is diagnosed earlier – which may be possible from a noninvasive infrared
scanning system being developed by Johns Hopkins researchers.
Couples encouraged to examine each other for
suspicious moles that could be skin cancer. Researchers estimate that 40
– 50% of people in the U.S. who live to age 65 will have nonmelanoma
skin cancer at least once.
The prototype system works by looking for the tiny
temperature difference between healthy tissue and a growing tumor to
help doctors determine whether pigmented skin growths are benign moles
or melanoma.
The researchers have begun a pilot study of 50
patients at Johns Hopkins to help determine how specific and sensitive
the device is in evaluating melanomas and precancerous lesions.
Further patient testing and refinement of the
technology are needed, but if the system works as envisioned, it could
help physicians address a serious health problem: The National Cancer
Institute estimated that 68,720 new cases of melanoma were reported in
the United States in 2009; it attributed 8,650 deaths to the disease.
To avert such deaths, doctors need to identify a
mole that may be melanoma at an early, treatable stage. To do this,
doctors now look for subjective clues such as the size, shape and
coloring of a mole, but the process is not perfect.
"The problem with diagnosing melanoma in the year
2010 is that we don't have any objective way to diagnose this disease,"
said Rhoda Alani, adjunct professor at the Johns Hopkins Kimmel Cancer
Center and professor and chair of dermatology at the Boston University
School of Medicine.
"Our goal is to give an objective measurement as to
whether a lesion may be malignant. It could take much of the guesswork
out of screening patients for skin cancer."
With this goal in mind, Alani teamed with heat
transfer expert Cila Herman, a professor of mechanical engineering in
Johns Hopkins' Whiting School of Engineering. Three years ago, Herman
obtained a $300,000 National Science Foundation grant to develop new
ways to detect subsurface changes in temperature. Working with Muge
Pirtini, a mechanical engineering doctoral student, Herman aimed her
research at measuring heat differences just below the surface of the
skin.
Before scanning, the targeted skin is cooled with a brief burst
of compressed air.
Because cancer cells divide more rapidly than
normal cells, they typically generate more metabolic activity and
release more energy as heat. To detect this, Herman uses a highly
sensitive infrared camera on loan from the Johns Hopkins Applied Physics
Laboratory. Normally, the temperature difference between cancerous and
healthy skins cells is extremely small, so Herman and Pirtini devised a
way to make the difference stand out.
First, they cool a patient's skin
with a harmless one-minute burst of compressed air. When the cooling is
halted, they immediately record infrared images of the target skin area
for two to three minutes. Cancer cells typically reheat more quickly
than the surrounding healthy tissue, and this difference can be captured
by the infrared camera and viewed through sophisticated image
processing.
About Melanoma
Melanoma is the most
serious type of
skin cancer. Often the first sign of melanoma is a change in the
size, shape, color or feel of a mole. Most melanomas have a black or
black-blue area. Melanoma may also appear as a new mole. It may be
black, abnormal or "ugly looking."
Melanoma can be cured if
it is diagnosed and treated early. If melanoma is not removed in its
early stages, cancer cells may grow downward from the skin surface and
invade healthy tissue. If it spreads to other parts of the body it can
be difficult to control.
Melanoma is one of the rarer types
of skin cancer but causes the majority of skin cancer related
deaths.More at
Wikipedia
"The system is actually very simple," Herman said.
"An infrared image is similar to the images seen through night-vision
goggles. In this medical application, the technology itself is
noninvasive; the only inconvenience to the patient is the cooling."
The current pilot study is designed to determine
how well the technology can detect melanoma. To test it,
dermatologist-identified lesions undergo thermal scanning with the new
system, and then a biopsy is performed to determine whether melanoma is
actually present.
"Obviously, there is a lot of work to do," Herman
said. "We need to fine-tune the instrument -- the scanning system and
the software -- and develop diagnostic criteria for cancerous lesions.
When the research and refinement are done, we hope to be able to show
that our system can find melanoma at an early stage before it spreads
and becomes dangerous to the patient."
Alani, the skin cancer expert, is also cautiously
optimistic. "We, at this point, are not able to say that this instrument
is able to replace the clinical judgment of a dermatologist, but we
envision that this will be useful as a tool in helping to diagnose
early-stage melanoma," Alani said.
"We're very encouraged about the
promise of this technology for improving our ability to prevent people
from actually dying of melanoma."
The researchers envision a hand-held scanning
system that dermatologists could use to evaluate suspicious moles. The
technology also might be incorporated into a full-body-scanning system
for patients with a large number of pigmented lesions, they said.
The skin cancer scanning system is protected under
an international patent application submitted by the Johns Hopkins
Technology Transfer office, with Herman, Alani and Pirtini listed as the
inventors. No commercialization agreement has been reached, but the
technology transfer staff has engaged in talks with investors and
medical devices firms concerning possible licensing deals. Any business
arrangements involving the inventors would be managed by The Johns
Hopkins University in accordance with its conflict-of-interest policies.
