Glow-in-dark surgery may help cancer patients

Operating in the dark would be challenging for most surgeons. But for Indiana University Health's Dr. Emma Rossi, a dimly lit room can be as critical as a scalpel.

Rossi has been testing a new procedure to track the spread of gynecological cancers. She injects a fluorescent dye that glows in the dark into a patient and dims the lights in the operating room. Then she uses infrared imaging to track the path the cancer might have taken.

"We're trying to find the road that the cancer traveled on, because otherwise the road is invisible," said Rossi, an assistant professor of obstetrics and gynecology at the Indiana University School of Medicine.

Other doctors do this procedure, but it lacks government approval. Nor is there any evidence that it results in better outcomes than traditional surgeries.

So Rossi is leading a multicenter trial to compare old and new methods for treating gynecological diseases such as cervical and uterine cancer.

First, Rossi injects the dye that will light up the lymph nodes. She removes the ones that the dye pinpoints. Then she proceeds as usual, taking out the patient's uterus and other lymphatic tissue. A robot assists her, and the operation is minimally invasive, entailing only a few narrow incisions.

After the surgery, pathologists check lymph nodes for cancer. Often uterine cancer grows slowly and will not have spread. But when it has, Rossi hopes the dye will have located any cancerous nodes, indicating the patient should undergo chemotherapy.

Fewer side effects?

"It works; you can find lymph nodes with it," Rossi said. "But are these the lymph nodes that the cancer is in? We want to see that wherever there's cancer in the lymph nodes, that it's always in the lymph nodes that had dye."

Current treatment of gynecological cancers involves removing all tissue that could contain affected lymph nodes. That comes with the risk of side effects and complications, including swollen legs and nerve injuries.

The new procedure, called sentinel node mapping, could greatly reduce the number of lymph nodes that need to be removed.

A definitive answer could arrive too late to help Pamela Flannagan, a 68-year-old Avon, Ind., resident, but that didn't stop her from agreeing to participate in the trial.

A few years out from a leukemia diagnosis, Flannagan recently learned she had uterine cancer. She went to Rossi for a pre-surgical consultation and heard about the trial.

"I said, if it would help someone else, I would be glad to do it," she said. "I hope it helps someone down the road and me, too."

Lymph node mapping already helps treat other cancers, such as breast cancer. But cancers in organs that lie deep in the abdomen, such as gynecological ones, haven't proved as amenable to the technique.

Doctors tried using a radioactive substance to find the nodes. That, however, required personnel and a Geiger counter, making it time-consuming and expensive. They also tested a blue dye that was difficult to see.

Then a University of North Carolina gynecologist tried a fluorescent dye used in colon cancer. Not only did the compound stay in the lymph nodes long enough for doctors to find it, it also glowed through tissue, which could aid doctors working on obese patients.

That physician, Dr. John Boggess, a professor of gynecologic oncology at the UNC School of Medicine, assigned one of his fellows to develop a protocol for treatment.

Now he's participating in a trial that his former fellow, Rossi, is leading to show that it works. Other trials are under way but nothing approaching the scale of Rossi's, he said.

If this works, the process could help improve diagnosis and treatment. In some instances, doctors know cancer comes back even though they did not detect it in the lymph nodes. It's possible this technique will help doctors find the earliest beginnings of cancer that have previously gone unnoticed.

A guiding light

If the procedure works here, Rossi said, it's possible it could extend to other cancers that also have proved resistant to node mapping, such as bladder, rectal or even prostate cancer.

So far, Rossi said, the dye has located the correct sentinel lymph nodes in all of the patients whose cancer has spread.

Without dye, a surgeon cannot look at tissue and see the lymph nodes. Lymph nodes serve as filtering stations for clear fluid that runs through our body, carting around substances such as proteins, salt and urea.

A collection of white blood cells sits in each node to monitor fluid and remove anything foreign, such as infection. Most cancers hitch a ride in this fluid to spread from the initial organ.

There's no way to distinguish lymph nodes that drain fluid from a patient's uterus or bladder. That's where the dye enters the picture.

During a recent surgery, Flannagan lay asleep and draped on the operating room table in the basement of the IU Health Melvin and Bren Simon Cancer Center. Rossi and her colleagues inserted the robot's probe through small cuts in her belly and injected the dye into her uterus. The dye then followed the route of the lymph fluid and headed to those sentinel nodes.

Glowing in the dark

Rossi had the lights dimmed and sat at the robot's console, which looks like an elaborate video game, a few feet from the operating table. The robot includes infrared cameras, and when Rossi switched screens, the green dye showed up in stark contrast against the black-and-white picture.

Rossi manipulated the probes inside Flannagan to maneuver through her abdomen and remove lymph nodes as she found them.

"Dimming probably makes the screen a little clearer," she said. "It's kind of like looking at a View-Master."