Colorectal cancer is the second leading cause of death from cancer in Western countries.
Early detection by colorectal cancer screening can effectively cut its mortality rate.
CT colonography represents a promising, minimally invasive alternative to conventional methods of colorectal carcinoma screening.
In this prospective single institutional study, researchers in Switzerland compared the abilities of routine clinical CT colonography and conventional colonoscopy to detect colorectal neoplasms.
The researchers used second-look colonoscopy to clarify discrepant results.
The research group included 100 symptomatic patients who had undergone CT colonography.
The researchers used contrast enhanced multidetector CT followed by conventional colonoscopy on the same day.
If the researchers had found discrepant results, a second-look colonoscopy was performed after unblinding.
CT colonographic findings were compared with those of conventional colonoscopy.
The researchers noted 122 colorectal neoplasms in 49 patients after conventional colonoscopy.
The group calculated that the overall sensitivity of CT colonography at detecting patients with at least one polyp 6 mm or larger was 76% and its specificity was 88%.
|CT colonography had both a high by-patient sensitivity and specificity for detection of clinically important colorectal neoplasms|
|American Journal of Gastroenterology|
In addition, its by-patient sensitivity for polyps 10 mm or larger was 95% and its specificity was 98%.
By-polyp sensitivities were 71% for polyps 10 mm or larger, and 61% for polyps 6 mm or larger.
A second-look colonoscopy was performed in 19 patients and two initial false-positive findings of CT colonography were reclassified as true-positive.
For conventional colonoscopy, the researchers found that this produced a by-polyp sensitivity of 94% for detection of lesions 6 mm and larger.
Dr Hoppe, co-author of the report concluded, "CT colonography had both a high by-patient sensitivity and specificity for detection of clinically important colorectal neoplasms 10 mm or larger."
"This suggests that CT colonography has the potential to become a valuable clinical screening method for colorectal neoplasms."