Study objectives: We performed a clinical trial of
laser-induced fluorescence endoscopy (LIFE) for detection of
precancerous lesions and cancer including carcinoma in
situ (CIS), which are difficult to detect by white-light
Design: Results with LIFE were compared
with the criterion standard, white-light bronchoscopy. The evaluation
of these endoscopic results spectrofluorometrically was examined, and
pixels of LIFE images composed of digital signals for the intensities
of red and green were analyzed.
Tertiary-level hospital treating referrals and subjects with suspicious
results in mass screening.
Patients: We examined 65
subjects with suspected lung cancer by both methods, and performed
biopsy on 216 lesions.
Results: The accuracy of
diagnosis by white-light bronchoscopy, with histopathologic results as
the standard, was 48.6%. The accuracy by LIFE was 72.7%. The
sensitivity of conventional bronchoscopy for detection of severe
dysplasia (21 biopsy specimens) or cancer (28 biopsy specimens) was
61.2% and specificity was 85.0%. With results by LIFE added, these
values were 89.8% and 78.4%, respectively. Of nine patients with CIS,
only LIFE showed one lesion, and only LIFE showed the extent of seven
of the lesions. The autofluorescence of eight lesions was measured
spectrofluorometrically; normal bronchial tissue, severe dysplasia, and
cancerous tissue had spectral differences. The red/green intensity of
cancers on histograms of LIFE images generally was greater than the
ratios for metaplasia or normal bronchial wall.
Conclusions: Use of both methods should facilitate early
detection. Evaluation by spectrofluorometry and analysis of digital
signal intensity of results by LIFE make results more