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| 2. |
- Svanberg, Katarina, et al.
(författare)
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Photodynamic Therapy of Nonmelanoma Malignant-tumors of the Skin Using Topical Delta-amino Levulinic Acid Sensitization and Laser Irradiation
- 1994
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Ingår i: British Journal of Dermatology. - : Oxford University Press (OUP). - 1365-2133 .- 0007-0963. ; 130:6, s. 743-751
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Tidskriftsartikel (refereegranskat)abstract
- Eighty basal cell carcinomas (BCCs) in 21 patients, 10 lesions of Bowen's disease in three patients, and four lesions of cutaneous T-cell lymphoma in two patients, were treated with photodynamic laser therapy (PDT), using topical application of the haem precursor delta-amino levulinic acid (ALA). The diagnoses were confirmed histologically prior to treatment. Fifty-five of the BCCs were superficial lesions, and 25 were nodular. Of the 80 BCCs, 39 (49%) were located on the trunk, 36 (45%) on the head and neck region, four (15%) on the leg and one on the arm. The two principal locations of the 10 Bowen's disease lesions were the leg (50%) and the trunk (40%). The T-cell lymphoma lesions were located on the shoulder and on the arm. A water-in-oil based cream containing 20% ALA was applied to the lesions, with a margin of about 10-20 mm beyond the visible tumour border, 4-6 h before the laser procedure. During this period of time the highly fluorescent and photodynamically active substance protoporphyrin IX (Pp IX) is synthesized via the haem cycle. Laser-induced fluorescence (LIF) was used for real-time monitoring of the Pp IX distribution in the tumour and in the normal surrounding skin, before and after treatment in all patients. Before laser treatment the Pp-IX distribution demonstrated by LIF showed a demarcation between tumour and normal skin of about 15:1 for BCC and Bowen's disease, and 5:1 for T-cell lymphomas. Laser light from a pulsed frequency-doubled Nd:YAG laser pumping a dye laser with light emission at 630 nn was used for the therapy. The power density in the irradiation was kept below 110 mW/cm(2), in order to avoid hyperthermal effects. A total energy of 60 J/cm(2) was delivered for 10-20 min, depending on the tumour size. A complete response rate of 100% in superficial BCCs and 64% in nodular BCCs occurred after a single laser treatment, and a response rate of 100% was achieved after one additional. treatment in the nodular BCCs. in the Bowen's disease lesions a complete response of 90% was obtained with a single treatment. Two of the four T-cell lymphomas resolved completely. The follow-up time was between 6 and 14 months.
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| 3. |
- 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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| 4. |
- 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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| 6. |
- Andersson-Engels, Stefan, et al.
(författare)
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Effects of Optical-constants On Time-gated Transillumination of Tissue and Tissue-like Media
- 1992
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Ingår i: Journal of Photochemistry and Photobiology, B: Biology. - 1011-1344. ; 16:2, s. 155-167
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Tidskriftsartikel (refereegranskat)abstract
- Light transillumination was used to study structures inside turbid media. Time-gated viewing was performed to suppress multiply-scattered light and thus improve spatial resolution. We demonstrate that, for the case of scattering-dominated attenuation (scattering coefficient much greater than the absorption coefficient), the detection of early transmitted light will be practically insensitive to variations in the absorption coefficient. This is an important observation for the development of time-gated optical mammography, since optical mammography using continuous-wave light is based on increased light absorption in the tumour region caused by the neovascularization surrounding a tumour. In order to detect tumours in time-gated viewing it is the scattering coefficient of the tumour that must be characteristic. The scattering coefficient is measured to be lower in the tumour region than in the surrounding breast tissue for one resected breast specimen.
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| 9. |
- 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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