| 2. |
- Eker, C, et al.
(författare)
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Clinical spectral characterisation of colonic mucosal lesions using autofluorescence and delta aminolevulinic acid sensitisation
- 1999
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Ingår i: Gut. - : BMJ. - 1468-3288 .- 0017-5749. ; 44:4, s. 511-518
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Tidskriftsartikel (refereegranskat)abstract
- Background and aims-Laser induced fluorescence (LIF) from colonic mucosa was measured in vivo with and without delta 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.
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| 3. |
- Liu, D. L, et al.
(författare)
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Intra-operative laser-induced photodynamic therapy in the treatment of experimental hepatic tumours
- 1995
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Ingår i: European Journal of Gastroenterology and Hepathology. - 1473-5687. ; 7:11, s. 1073-1080
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To examine the effect of photodynamic therapy (PDT) on experimental liver tumours in rats. Design: An experimental liver tumour model was used. Each of a group of Fats had two tumours simultaneously inoculated into its liver. The tumour located in the left hepatic robe was used for PDT, and the other one, in the median lobe, as a control. The haem precursor delta-amino laevulinic acid (ALA), at a dose of 30 mg/kg body weight, was injected 60 min before laser irradiation. Rats in group I received ALA through a femoral vein. Those in group II received ALA through the portal vein. Group III had an injection of ALA solution through the portal vein plus hepatic inflow occlusion. Three and 6 days after the treatment, the rats were killed, and the tumours were measured, and ultrastructural changes were examined using scanning electron microscopy. Setting: Lund University Medical Laser Centre, Lund, Sweden. Results: The mean tumour volume of the treated tumours increased by factors of 1.9, 1.5 and 1.7 in groups I, II and III, respectively, compared with the pretreatment baseline value. However, the mean tumour volume in the control tumours increased by factors of 9.5, 4.3 and 4.8 in the respective groups. Under the light microscope, marked necrosis of the treated tumour and the surrounding liver tissue was observed. Scanning electron microscopy revealed heavy damage to the cells and vessels in the treated tumour. Conclusion: PDT with ALA is an effective treatment modality for rat liver tumours.
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