CHICAGO, Nov 26, 2001 (United Press International via COMTEX) -- New computer-aided detection software -- sort of "spell-checkers" for the radiologist -- can spot lung and colon cancers that doctors miss, increasing chances of diagnosing cancer earlier when it is more likely to produce a cure.

Researchers said the computerized programs not only spot suspicious-looking tissue that even the best-trained doctors overlook, but they can also dramatically cut the time it takes doctors to review images taken by sophisticated imaging devices.

"It's astounding to see how many images a radiologist might look at in a computerized tomography (CT scan) procedure. There are hundreds, sometimes a thousand images," said David Paik, a National Library of Medicine fellow in the department of radiology at Stanford University. Paik spoke at a press briefing Monday during the annual meeting of the Radiological Society of North America in Chicago, Ill.

"With the increased use of CT scans for the detection of lung cancer and other disease, radiologists' workloads have increased tremendously. Computer assistance in reviewing and interpreting hundreds of images may be quite helpful," said Samuel Armato III, assistant professor of radiology at the University of Chicago in Illinois.

Recently, computerized devices were approved by the Food and Drug Administration for assisting doctors in reading mammographies. The mammography screen, however, involves only four images not the hundreds that are created by the CT scans.

Paik said that doctors routinely take about 15 minutes to complete an examination of colon cancer CT scans. Using the still experimental computer-assisted programs, Paik said doctors in his study reduced the time to seven minutes, and he said he expected that time would be reduced even further as doctors become more familiar and more trusting of the programs.

His program picked out all 51 cancers that radiologists had missed. The program also suggested that other anatomical points might be suspicious -- false positives, Paik said. Continuing experimentation will be required to try to reduce the number of those false-positives.

"The computer is not perfect," Armato said. "It will miss some cancers and call some things cancer that aren't. The radiologist can identify normal anatomy that the computer may mistake for something suspicious."

In his study, Armato said the computer scanned 38 CT lung scans and found 41 of 50 suspicious nodules. Of the 38 nodules that were found to be cancerous -- and had been missed by radiologists -- the computer identified 30 of them.

Overall, Armato said, the computer found about 80 percent of previously missed cancers.

However, Paik said that radiologists don't have to be concerned that they will be replaced by computers. "This will become a power tool for radiologists that will make them more effective," he predicted.

The development of the programs is ongoing with funding provided by the National Institutes of Health.

"It is fairly well determined that early diagnosis and treatment of colon cancer does increase survival," Paik said.

Armato said researchers still consider controversial the idea that early detection can impact mortality in lung cancer.

From Healthy.net