Catching colon cancer

EXETER, N.H.

The radiologist peers into Pauline Morse's colon, pausing to inspect a fleshy fold before moving deeper into the shadowy twists and turns.

But Morse, 73, isn't lying on a table during this intimate tour of her insides -- she's at home. The images were created with a virtual colonoscopy -- a new procedure that relies on a computer scan instead of a scope to reveal cancer or suspicious growths.

Morse is among the early participants in the most comprehensive study yet to directly compare virtual or computer tomography colonoscopy to traditional colonoscopy, the gold standard for colorectal cancer screening. The comparison is important because the new procedure, though available at some hospitals, is considered experimental and not covered by most insurance.

The procedure is not yet available at either Cape Girardeau hospital.

During a colonoscopy, a doctor uses a flexible tube to view a sedated patient's entire colon and remove any suspicious growths that are discovered.

In a virtual colonoscopy, a CT scanner takes hundreds of X-rays of the colon. Sophisticated computer software combines the "slices" to produce two-dimensional images, which are analyzed later for growths. With a few clicks of a computer mouse, a radiologist can view the colon from every imaginable angle, zoom in on select areas and do a "fly-through" tour.

"You just lie on the bed, hold your breath, and they put you in the machine," Morse said.

Patients don't need sedation, and they can return to work the same day as the procedure. But if the scan shows tumors or precancerous polyps, a traditional colonoscopy is needed to remove them.

"The big advantage is it's a quick test and it's noninvasive," said Dr. Geetanjali Akerkar, the study's principal investigator at Exeter Hospital. "If this test proves to be a very good test in terms of detecting polyps and cancer, then patients would be on a CT scan machine for five minutes, and if it's negative, they're pretty much finished."

Someone having the new procedure would be in and out of the hospital in less than half an hour, she said. A traditional colonoscopy lasts about 30 minutes, but because it involves sedation, patients typically spend about three hours in the doctor's office or hospital.

The study was funded by the National Cancer Institute.

Despite the "whiz-bang technology," virtual colonoscopy may not be better, said Dr. David Weinberg, directo of gastroenterology at Philadelphia's Fox Chase Cancer Center. But he said the study might produce other valuable insights -- showing how to reduce the onerous test preparations, for example, or reducing the cost of testing.

Morse, whose brother had colon cancer, signed up for the study after her doctor found blood in her stool. She rated the virtual colonoscopy the most comfortable, but said none of the tests was unbearable.

The tests revealed a small polyp that was removed and found to be benign, she said.