A Closer Look at Cancer (Daily Press)

Hampton University physics professor Cynthia Keppel and Jefferson Lab scientist Stan Majewski display an instrument they developed that can detect small cancerous growths. Below, they demonstrate how it works.
Photos by Kenneth D. Lyons/Daily Press
probe.jpg (12761 bytes)

A Closer Look at Cancer

Jefferson Lab, HU probe ready for additional testing

NEWPORT NEWS - Normally, there's nothing good about finding cancer.

But when Cynthia Keppel learned that a tiny growth taken from the thigh of a North Carolina patient was malignant, she had a reason to smile.

A medical probe she's helping develop had passed an important test: It had led a doctor from the East Carolina University Medical Center to a 1-centimeter growth that may otherwise have gone undetected until it had doubled in size.

"At that point, there would have been a good possibility the cancer had spread more," said Keppel, assistant professor of physics at Hampton University. "For the patient -- this man who had skin cancer -- the clock would have been ticking. I was so excited to hear this had worked."

HU, in partnership with the Thomas Jefferson National Accelerator Facility, is working on several intraoperative surgical probes -- compact, portable instruments used in the operating room -- to fight cancer. Through nuclear physics technology, researchers hope to help doctors find cancerous tissue at an earlier stage and avoid removing healthy tissue.

Lorraine Tafra, a doctor at East Carolina University, and local doctors plan to test the instruments. The first probe that was tested on a patient -- the man in North Carolina with skin cancer -- is ready to go into more extensive patient trials this year.

The probe, patented by HU and the Jefferson Lab, remains in the experimental phase. But several companies already have contacted the Jefferson Lab about marketing it commercially in the future, said Stan Majewski, a senior scientist at the lab.

"It seems to be much more sensitive than other nuclear medicine options," Majewski said. "It's breaking a barrier. We think it has the potential to expand lives."

Researchers, who have opened a lab at the Applied Research Center, built the surgical probe to find tumors as small as a centimeter in diameter. Currently, doctors often can't detect tumors until they grow to two or three centimeters, Majewski said.

The probe looks like a short silver rod, about 10 inches long and a half-inch wide. A stainless steel tube encompasses a radiation sensor. It can't diagnose cancer or help patients avoid biopsies or surgery, but it may help doctors find cancer without as much trauma during operations.

"You want to avoid cutting up the patient," Keppel said. "If you know more exactly where the cancer is, you can do that."

The probe is used after existing imaging equipment has shown doctors the approximate, but not exact, location of cancerous tissue. During surgery, doctors slowly wave the probe over the area, watching and listening. When the probe hits potentially abnormal tissue, its soft wailing noise gets louder and the flashing green lights on its tip turn red.

The basic idea behind the probe is that fast-growing cancer cells take up and burn more energy than normal cells. Doctors inject the patient with a sugar-based solution that includes a small amount of radiation.

As cancer cells gobble up the solution, radiation collects in them. The probe can sense those concentrations.

"If it finds something, it's not definitely cancer," Keppel said, "but it's an important indication that there could be cancer."

Keppel and Majewski believe the probe could work on patients with many types of cancer. One of the most promising, they say, is melanoma, a type of skin cancer that can grow deep into the skin and spread through the lymph and blood vessels.

"This is something that's very aggressive and difficult to control," Majewski said. "If you don't catch it early, it usually means trouble."

A barrier to widespread testing is that few hospitals have a positron emission tomography machine, the expensive imaging equipment that works with the probe. But researchers hope the machines will come to more hospitals in the future.

Another probe about to go into patient testing is designed to avoid removing lymph nodes that are noncancerous. Doctors would use that probe to help pinpoint the first lymph node in a chain, known as the sentinel node.

While some questions remain, results to date have shown that if the sentinel node is not cancerous, there is a good chance the others in the chain are negative as well, said Richard Hoefer, a doctor with Oyster Point Surgical Associates in Newport News. Hoefer hopes to start testing the Jefferson Lab probe this spring at Riverside Regional Medical Center.

Speaking generally about the probes, Hoefer said anything that can minimize trauma from surgery is good news for cancer patients.

"There's a lot of pain and discomfort we could get rid of," he said. "These could be very helpful down the road."

Research on the probes is funded through grants from the National Science Foundation and support from HU and Jefferson Lab.

"We want to develop a whole family of tools," Keppel said. "We think the opportunities are endless."