Virtual colonoscopy a less invasive cancer screener

Jiggering a computer mouse up, down and sideways like a teenager playing a video game, Dr. Tim Hanes guides his cursor through the curves and dips of a brown wrinkly tunnel that looks like it’s out of Alice in Wonderland, searching for lurking monsters.

“Hey, there’s one,” said Hanes, a radiologist at St. Joseph’s Hospital in Atlanta, pointing with his cursor to a glob on his computer screen that looks like a large gooey marble. “It’s a big one.”

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Jason Getz/Staff

Virtual colonoscopy creates a 3D computer image such as this one, which was produced from a CAT scan at St. Joseph’s Hospital in Atlanta.

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Jason Getz/Staff

Radiologist Timothy Hanes discusses the virtual imaging process at St. Joseph’s Hospital. Through virtual colonoscopy, polyps are found on computer images instead of via photographs.

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Jason Getz/Staff

A patient waits in the ready position before a CAT Scan Colonography is done by a CT 64 slice scan machine at St. Joseph’s Hospital.

WHAT IS VIRTUAL COLONOSCOPY?

• Also called CT colonography, it's an X-ray test that looks for cancer and precancerous polyps, precancerous growths, in the colon (large bowel).
• Patients lie on their backs and sides on a gurney, which moves through a CT machine. If polyps are detected, patients have to return for a traditional colonoscopy.
• Currently virtual colonoscopy is not covered by Medicare or other insurance, but that is expected to change by year's end.
• The X-rays taken by the CT scanner are put together digitally by computer, but radiologists who "read" the scans see images that look as if they are traveling through a real colon.
• No sedation is required, though air is pumped into the colon to make it easier for the X-rays to spot any abnormalities.
• Current advice is for virtual colonoscopies to be repeated every five years, compared to 10 years for traditional colonoscopies.
• Source: St. Joseph's Hospital

FACTS ABOUT COLON SCREENING

• Regular colon screening should begin at age 50 for people with average risk of colon cancer, except for African-Americans, who should be screened at 45.
• In traditional colonoscopy, long tube called colonoscope with camera on end is inserted into rectum and allows doctor to look at, in real time, your entire colon. In this procedure, which requires patients to be anesthetized, any polyps found, which are considered pre-cancerous, can be removed. Procedure can take an hour, and patient must be picked up and driven home and can expect to be groggy all day.
• In virtual colonography, a small device just a few inches long is inserted into patient's rectum. The person lies on a gurney and is run through a CT scanner that takes X-ray views of the insides of the bowel, and also surrounding areas. No anesthesia is required, and patient is finished in less than 20 minutes, and can perform normal daily activities.
• In both traditional and virtual colon procedures, patients must "prep" the night before by taking laxatives to cleanse bowels.
• Currently, most insurance pays for colonoscopies, which can cost up to $3,000, but not for virtual colonoscopies, also called CT colonographies, which cost about $500. The federal government is expected to approve the virtual tests for insurance purposes later this year.
• Source: St. Joseph's Hospital, Atlanta

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The monster is a polyp, sprouting inside a patient’s large intestine like a mushroom, and it’s dangerous because many turn into malignant growths that cause nearly 150,000 cases of colon cancer a year, killing about 41,000 people.

Colon cancer is the second leading cause of cancer death behind lung cancer, which is why doctors say everyone 50 and over should be screened. The risk is greater for African-Americans, who are recommended for screening at age 45.

“It takes 10 years to go from a small polyp to colon cancer that’ll kill you,” said Hanes, 39.

He’s sitting in front of a computer screen in a darkened room, diving ever deeper through the twists and turns of an anonymous patient’s guts by means of a virtual colonoscopy — which transforms into life-like 3-D images the innards of people moving slowly on a gurney through the doughnut hole of a CT scanner.

“This looks kind of like a ride at DisneyWorld, where you go through parts of the human body,” he said.

Faster and easier

Virtual colonoscopies, a new, less-invasive procedure, creates images that are hard to distinguish from real pictures produced by cameras used in a conventional colonoscopy. In conventional colonoscopies, doctors use a colonoscope – a thin instrument tipped by a tiny camera — to snake through a patient’s intestine, looking for pre-cancerous polyps and snipping them out when found.

The conventional procedure can take up to an hour, be done in doctors’ offices or hospital suites and patients must be heavily sedated or put to sleep.

In virtual colonoscopies, which take 15 minutes or less, no sedation is required, because only a tiny, two-inch long catheter is inserted into the rectum. It pumps air into the colon to make it easier for the X-rays from the CT scanner to form better virtual images of polyps or other abnormalities.

Anchorwoman Katie Couric, whose husband died of colon cancer, famously chose not to be knocked out and watched the exploration of her colon live along with millions of TV viewers.

Some people want to watch, but most are put to sleep.

Both methods require bowel cleansing the night before, which many patients dread more than the procedures themselves.

“It’s a real tremendous pain,” said Joey Fischer, 67, of Sandy Springs, who has had both types of procedures. “You have to stay away from solid food the day before, then drink a huge amount of liquid laxative stuff to clear yourself out. You’re constantly running to the bathroom.”

… and cheaper too

Still, patients are increasingly opting for the virtual procedure, even though it means they have to do the cleansing twice if polyps are found. When that happens, Hanes said, patients must go to a gastroenterologist to have the polyps removed.

Fischer said his “guts weren’t made for that long tube” and that he has scarring in his colon that makes it hard to move the scope.

“Six months ago the doctor couldn’t get it through and that’s when they recommended the virtual,” he said.

The possibility of having to prep twice is a major disadvantage of the virtual procedure, which does have advantages. Patients don’t have to be put to sleep and can be at work within a half hour of having the CT screening.

Those who undergo the conventional test must be heavily sedated, are often groggy for an entire day, and run the rare but dangerous risk of having their intestines perforated by the colonoscope.

Conventional colonoscopies can cost $3,000, which is almost always covered by insurance. The virtual screenings cost about $500, but usually aren’t covered.

Hanes said the U.S. Department of Health and Human Services is expected to rule next month that the virtual procedure should be covered by Medicare because evidence indicates it works. And if that happens, Hanes said, it’s a good bet that private insurers will follow suit.

A good match

The virtual procedures are almost as accurate as the real colonoscopies, according to a Sept. 18 study in the New England Journal of Medicine.

It reported that virtual colonoscopies catch 90 percent of large, precancerous polyps — the same accuracy rate as conventional procedures, said Dr. Durado Brooks, director of colorectal cancer of the American Cancer Society.

He said it’s “very impressive” how closely the virtual and camera views match. And the virtual test has been endorsed by the American Cancer Society, all the major gastrointestinal organizations and the American College of Oncology.

Eddie Koger, 53, of Ringgold, is impressed, too. When his doctor told him he was overdue for a colonoscopy, he turned to the Internet, and his research led him to Emory University, whose hospital, along with St. Joseph’s, is among a relatively small number offering the virtual procedure.

“The compelling thing for me was, it was less invasive,” Koger said.

Unfortunately, he said, his scan revealed that he had a polyp, which meant he had go to a local hospital three weeks later to have it removed in a conventional colonoscopy.

Doctors recommend that people 50 and over get their colons screened for polyps every 10 years, or five if the procedures are done with a CT scanner.

“I’m hoping hospitals will be able to do the virtuals and if they find any polyps, take you right over to the gastroenterologists and have them taken out,” Koger said.

When insurance starts paying for the virtual screenings, they’re “going to take off like gangbusters,” said Linda Byrd, digestive disease navigator at St. Joseph’s.

“Like science fiction”

And just over the horizon is a new, more powerful CT machine that, with specialized software, will be able to take virtual images of peoples’ colons even if they haven’t cleansed their bowels, Byrd said.

Brooks said patients who cringe at the prospect of having to cleanse before screenings ought to search out the few centers where the radiology and gastroenterology departments operate more as a team.

“It’s my impression that this sort of coordination is pretty infrequent,” he said.

Colon cancer is highly curable if people follow the advice of doctors, but Brooks said “most people are reluctant” unless they have pain or symptoms.

Though some experts warn that CT colonographies expose patients to too much radiation, Emory radiologist Dr. Bill Small said people 50 and over “typically do not have, actuarially, that many years of life left that they should worry about radiation-induced cancer.”

“The risk of having an undetected polyp would be far worse,” Hanes said.

He peered into the cave-like image on his screen, again finding a polyp.

“It’s pretty amazing,” Hanes said. “Maybe we should have Star Wars music playing in the background in the screening room.”

That would suit Fischer just fine.

“This is a lot like science fiction,” he said in an earlier interview.

But the results are very real and Koger encourages everyone to be screened because despite its high fatality rate, colon cancer can be cured if detected early.