| 21. |
- af Klinteberg, C, et al.
(författare)
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Kinetic fluorescence studies of 5-aminolaevulinic acid-induced protoporphyrin IX accumulation in basal cell carcinomas
- 1999
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Ingår i: Journal of Photochemistry and Photobiology, B: Biology. - 1011-1344. ; 49:2-3, s. 120-128
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Tidskriftsartikel (refereegranskat)abstract
- Laser-induced fluorescence (LIF) investigations have been performed in connection with photodynamic therapy (PDT) of basal cell carcinomas and adjacent normal skin following topical application of 5-aminolaevulinic acid (ALA) in order to study the kinetics of the protoporphyrin TX (PpIX) build-up. Five superficial and 10 nodular lesions in 15 patients are included in the study. Fluorescence measurements are performed prior to the application of ALA, 2, 4 and 6 h port ALA application, immediately post PDT (60 J cm(-2) at 635 nm), and 2 h after the treatment. Hence, the build-up, photobleaching and re-accumulation of PpIX can be followed. Superficial lesions show a maximum PpIX fluorescence 6 h post ALA application, whereas the intensity is already the highest 2-4 h after the application in nodular lesions. Immediately post PDT, the fluorescence contribution at 670 Mm from the photoproducts is about 2% of the pre-PDT PpIX fluorescence at 635 nm. Two hours after the treatment, a uniform distribution of PpIX is found in the lesion and surrounding normal tissue. During the whole procedure, the autofluorescence of the lesions and the normal skin does not vary significantly from the values recorded before the application of ALA. (C) 1999 Elsevier Science S.A. All rights reserved.
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| 22. |
- Alian, Wael A, 1970, et al.
(författare)
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Laser-induced fluorescence studies of meso-tetra(hydroxyphenyl)chlorin in malignant and normal tissues in rats.
- 1994
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Ingår i: British journal of cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 70:5, s. 880-5
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Tidskriftsartikel (refereegranskat)abstract
- meso-Tetra(hydroxyphenyl)chlorin (mTHPC) is an attractive second-generation dihydroporphyrin photosensitiser for use in photodynamic therapy. In this study, 1.3 mg kg-1 body weight mTHPC was administered intravenously, and laser-induced fluorescence was used to characterise and compare its localisation and retention in different rat tissues, including an induced experimental adenocarcinoma, 24 h and 48 h post injection. These studies were performed in an attempt to predict the anatomical locations where mTHPC PDT might be most effective and suggest suitable injection--irradiation intervals in each case. Of particular interest were the intra-abdominal and intrathoracic tissues. The fluorescence was induced at 405 nm and the fluorescence spectrum in the region 450-750 nm was analysed. All collected spectra were dominated by the fluorescence signature of mTHPC with its peak at 652 nm, and all values in this study are in terms of background-free drug-specific fluorescence intensity at that wavelength. The photosensitiser accumulated in high concentrations in the tumour and the reticuloendothelial system. Muscular organs, such as the heart and the abdominal wall, were characterised by a low drug fluorescence signature.
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| 23. |
- Andersson-Engels, Stefan, et al.
(författare)
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Clinical fluorescence imaging
- 2008
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Ingår i: Lasers in Medicine.
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 24. |
- Andersson-Engels, Stefan, et al.
(författare)
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Clinical recording of laser-induced fluorescence spectra for evaluation of tumour demarcation feasibility in selected clinical specialities
- 1991
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Ingår i: Lasers in Medical Science. - 0268-8921. ; 6:4, s. 415-424
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Tidskriftsartikel (refereegranskat)abstract
- Laser-induced autofluorescence spectra from humans were recorded in vivo at three different clinics in a study aimed at investigating the capability of this method to discriminate between malignant tumours and normal surrounding tissues. For the recordings a mobile trolley with the necessary equipment was constructed for use in an examination room or in an operating theatre environment. Laser light was guided through a 600m optical fibre to the target tissue. The fluorescence from the excited tissue was collected with the same fibre and was fed to an optical multichannel analyser. Two excitation wavelengths were used (337 and 405 nm) in order to optimize the fluorescence signals in two interesting wavelength regions (380–500 and 550–700 nm). Oral and oropharyngeal tumours excited with 405 nm light contained detectable endogenous porphyrins and were in this way discriminated from the normal mucosa. Astrocytoma grade III–IV fluorescence different from that of normal brain tissue, while tumours in the bronchial tree were not detectable using the spectral shape of the pure tissue autofluorescence.
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| 25. |
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| 26. |
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| 27. |
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| 28. |
- Andersson-Engels, Stefan, et al.
(författare)
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Fluorescence Imaging and Point Measurements of Tissue - Applications To the Demarcation of Malignant-tumors and Atherosclerotic Lesions From Normal Tissue
- 1991
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Ingår i: Photochemistry and Photobiology. - 0031-8655. ; 53:6, s. 807-814
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Tidskriftsartikel (refereegranskat)abstract
- The possibilities of using laser-induced fluorescence for tissue diagnostics are discussed. The tissue types investigated are malignant tumors and atherosclerotic lesions. Studies with natural autofluorescence as well as with fluorescent tumor markers are included in this paper. Fluorescence emission and decay data are presented for some tissue chromophores contributing to tissue autofluorescence. Optical spectroscopic characteristics of fluorescent malignant tumor markers are analyzed and instrumental designs for clinical applications are discussed. Images recorded with a multicolor fluorescence imaging system developed in Lund are presented.
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| 29. |
- Andersson-Engels, Stefan, et al.
(författare)
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Identification of brain tumours in rats using laser-induced fluorescence and haematoporphyrin derivative
- 1989
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Ingår i: Lasers in Medical Science. - 0268-8921. ; 4:4, s. 241-249
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Tidskriftsartikel (refereegranskat)abstract
- Laser-induced fluorescence has been used for the identification of brain tumours in rats, which have been previously given tumour-seeking haematoporphyrin derivative. A pulsed nitrogen laser (λ=337 nm) was used in conjunction with an optical multichannel analyzer. For both inoculated RG-2 and TCVC rat-brain-tumour models, the blue autofluorescence was strongly reduced in the tumour compared with normal brain tissue, and at the same time the characteristic red-drug signal increased. The contrast between tumour and normal tissue was strongly enhanced by forming the ratio between the two signals. Implications for possible improvement of tumour delineation in brain tumour surgery are discussed.
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| 30. |
- Andersson-Engels, Stefan, et al.
(författare)
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In vivo fluorescence imaging for tissue diagnostics
- 1997
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Ingår i: Physics in Medicine and Biology. - : IOP Publishing. - 1361-6560 .- 0031-9155. ; 42:5, s. 815-824
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Tidskriftsartikel (refereegranskat)abstract
- Non-invasive fluorescence imaging has the potential to provide in vivo diagnostic information for many clinical specialities. Techniques have been developed over the years for simple ocular observations following UV excitation to sophisticated spectroscopic imaging using advanced equipment. Much of the impetus for research on fluorescence imaging for tissue diagnostics has come from parallel developments in photodynamic therapy of malignant lesions with fluorescent photosensitizers. However, the fluorescence of endogenous molecules (tissue autofluorescence) also plays an important role in most applications. In this paper, the possibilities of imaging tissues using fluorescence spectroscopy as a mean of tissue characterization are discussed. The various imaging techniques for extracting diagnostic information suggested in the literature are reviewed. The development of exogenous fluorophores for this purpose is also presented. Finally, the present status of clinical evaluation and future directions are discussed.
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