Report in English with a Dutch summary (KCE reports 45A)

90 Screening for Colorectal Cancer KCE reports vol.45
With regard to CT Colonography (CTC) for the detection of colorectal polyps
and neoplasms, the ICSI Technology Assessment Committee 328 concluded in its
active HTA report, approved in 2004 and reviewed bi-annually e :
5.5.8 Other techniques
e and revised, if warranted.
f approximately 20 mSv.
1. CTC is a safe procedure with minor side effects reported.
There is however radiation exposure f. The optional use of an
intravenous and/or intraluminal contrast agent would potentially
increase the morbidity and mortality risk.
2. A single study with a screening population found good sensitivity
and specificity for CTC compared with conventional
colonoscopy when images were interpreted by trained
radiologists who had read a minimum of 25 CTC studies. There
were no significant differences between the sensitivities of CTC
and conventional colonoscopy for the detection of adenomas >
5 mm or 10 mm (all sensitivities approximately 90%). The
specificity of CTC 79,6% for adenomas > 5 mm and 79,6% for
adenomas 10 mm. The CTC procedure in this study included
technical variations (i.e., use of 2 oral contrast agents, a multidetector
CT scanner, thin collimation, and a 3-dimensional "flythrough"
analysis for primary review). It is unclear which, if any,
of these variables contributed to the improved sensitivity of
neoplasm detection. At present, this protocol is not uniformly
used as many centers performing CTC do not have the required
hardware or software.
3. In a screening population, with the present data acquisition and
interpretation protocols, it is unclear how CTC compares with
conventional colonoscopy in terms of sensitivity and specificity
due to limited available data. CTC is potentially useful for
patients unwilling to undergo conventional colonoscopy or
other procedures, who have failed conventional colonoscopy
(incomplete examination of the colon), or who cannot be
sedated. However, patients with positive findings on CTC
(approximately 15% of the population) will require conventional
colonoscopy to obtain biopsy specimens.
4. CTC appears to be superior, in terms of detection of colorectal
polyps and neoplasms, to no examination, fecal occult blood
test, double-contrast barium enema, and FS. CTC has not been
proven to be superior to conventional colonoscopy.
5. Patient acceptance of CTC appears to be at least as good as
acceptance of conventional colonoscopy. Due to variations in
study protocols, it is unclear how sedation at conventional
colonoscopy and bowel relaxants at CTC may affect patient
ratings.
There have been no published RCTs on digital rectal examination as a screening
strategy for colorectal cancer. A case-control study showed no effect on
colorectal cancer mortality 390.