Background and study aims: Endoscopic optical diagnosis can potentially replace histopathological evaluation
of small colorectal lesions. The aim of this study was to evaluate diagnostic performance
of WavSTAT, a novel system for automatic optical diagnosis based on laser-induced
autofluorescence spectroscopy.
Patients and methods: Consecutive patients who were scheduled for colonoscopy were included in the study.
Each detected lesion with a size of ≤ 9 mm was differentiated using high resolution
endoscopy (HRE) by the endoscopist, who then reported this as a low or high confidence
call. Thereafter, all lesions were analyzed using WavSTAT. Histopathology was used
as the reference standard. The primary outcome measures were the accuracy of WavSTAT
to differentiate between adenomatous and nonadenomatous lesions, and the accuracy
of an algorithm combining HRE (lesions differentiated with high confidence) and WavSTAT
(all remaining lesions). The secondary outcome measure was the accuracy of on-site
recommended surveillance intervals.
Results: At total of 87 patients with 207 small colorectal lesions were evaluated. Accuracy
and negative predictive value of WavSTAT were 74.4 % and 73.5 %, respectively. The
corresponding figures for the algorithm were 79.2 % and 73.9 %, respectively. Accuracy
of on-site recommended surveillance interval was 73.7 % for WavSTAT alone and 77.2 %
for the algorithm of HRE and WavSTAT.
Conclusions: Both accuracy of WavSTAT alone and the algorithm combining HRE with WavSTAT proved
to be insufficient for the in vivo differentiation of small colorectal lesions, and
do not fulfill American Society for Gastrointestinal Endoscopy performance thresholds
for assessment of diminutive lesions. Future studies should assess whether combining
WavSTAT with more advanced imaging techniques could result in a higher accuracy.
Netherlands Trial Registry (NTR 3235).
