RT Journal Article
SR Electronic
T1 Clinical spectral characterisation of colonic mucosal lesions using autofluorescence and δ aminolevulinic acid sensitisation
JF Gut
JO Gut
FD BMJ Publishing Group Ltd and British Society of Gastroenterology
SP 511
OP 518
DO 10.1136/gut.44.4.511
VO 44
IS 4
A1 C Eker
A1 S Montán
A1 E Jaramillo
A1 K Koizumi
A1 C Rubio
A1 S Andersson-Engels
A1 K Svanberg
A1 S Svanberg
A1 P Slezak
YR 1999
UL http://gut.bmj.com/content/44/4/511.abstract
AB BACKGROUND AND AIMS Laser induced fluorescence (LIF) from colonic mucosa was measured in vivo with and without δ aminolevulinic acid (ALA) in an attempt to differentiate between neoplasia and non-neoplasia in real time during colonoscopy.METHODS Spectra from 32 adenomas, 68 normal sites, and 14 hyperplastic polyps in 41 patients were obtained with a point monitoring system. Twenty one of the patients had been given a low dose of ALA as a photosensitiser before the examination. Light of 337, 405, or 436 nm wavelength was used as excitation. Stepwise multivariate linear regression analysis was performed.RESULTS With 337 nm excitation, 100% sensitivity and 96% specificity was obtained between normal mucosa and adenomas. Seventy seven per cent of the hyperplastic polyps were classified as non-neoplastic. When exciting with 405 and 436 nm, the possibility of distinguishing different types of tissue was considerably better in the ALA patients than in the non-ALA patients.CONCLUSIONS The in vivo point measurements imply that a good discrimination between normal tissue and adenomatous polyps can be obtained using the LIF technique. Excitation at 337 nm and at 405 nm or 436 nm using ALA gives good results. LIF also shows potential for distinguishing adenomatous from hyperplastic polyps. The number of detection wavelengths could be reduced if chosen properly.ALAδ aminolevulinic acidLIFlaser induced fluorescenceMVLRmultivariate linear regressionPpIXprotoporphyrin IX