| 1. |
- Andersson-Engels, Stefan, et al.
(author)
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Preliminary evaluation of two fluorescence imaging methods for the detection and the delineation of basal cell carcinomas of the skin
- 2000
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In: Lasers in Surgery and Medicine. - 0196-8092. ; 26:1, s. 76-82
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Journal article (peer-reviewed)abstract
- Abstract Background and ObjectiveFluorescence techniques can provide powerful noninvasive means for medical diagnosis, based on the detection of either endogenous or exogenous fluorophores. The fluorescence of δ-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) has already shown promise for the diagnosis of tumors. The aim of the study was to investigate the localization of skin tumors after the topical application of ALA, by detecting the PpIX fluorescence either in the spectral or in the time domain.Study Design/Materials and MethodsTwo fluorescence imaging systems were used to identify basal cell carcinomas of the skin in humans, after topical application of 20% ALA ointment. Both systems rely on the comparison between the exogenous and the endogenous fluorescence, performed either in the spectral domain or in the time domain. The first system works by using three images acquired through different spectral filters, whereas the second one measures the spatial map of the average fluorescence lifetime of the sample.ResultsA clear demarcation of skin malignancies was successfully performed in vivo noninvasively with both fluorescence imaging systems.ConclusionThe two complementary approaches considered in the present study show promise for skin tumor detection and delineation based on specific fluorescence features. Lasers Surg. Med. 26:76–82, 2000. © 2000 Wiley-Liss, Inc.
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| 2. |
- Enejder, Annika M K, et al.
(author)
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Blood perfusion studies on basal cell carcinomas in conjunction with photodynamic- and cryo therapy employing laser-Doppler imaging
- 2000
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In: Acta Dermato-Venereologica. - : Medical Journals Sweden AB. - 1651-2057 .- 0001-5555. ; 80:1, s. 19-23
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Journal article (peer-reviewed)abstract
- Superficial blood perfusion mas monitored using laser-Doppler perfusion imaging in connection with a phase LII clinical trial comparing photodynamic therapy, utilizing topically applied aminoleuvlinic acid, with cryotherapy of basal cell, carcinomas. A total of 526 images mere recorded before and immediately after the treatment and during the follow-up period. Before treatment, the lesions exhibited a blood perfusion 3+/-2 times that in normal tissue. Both treatment modalities induced an increased blood perfusion inside the lesions, which slowly approached normal values in conjunction with successful treatments. The blood perfusion in successfully treated lesions approached normal values 2 months after photodynamic therapy, and about 1 year after cryotherapy, The tissue perfusion in recurrent lesions did not decrease to normal values after the treatment, suggesting that the laser-Doppler perfusion imaging technique can be used to follow the healing process and discover possible persistent tumour growth.
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| 3. |
- Johansson, Thomas, et al.
(author)
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Feasibility study of a system for combined light dosimetry and interstitial photodynamic treatment of massive tumors
- 2002
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In: Applied Optics. - 2155-3165. ; 41:7, s. 1462-1468
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Journal article (peer-reviewed)abstract
- A system for the photodynamic laser treatment of massive tumors that employs multiple optical fibers to be inserted into the tumor mass is described. The light flux through the tumor can be assessed by use of the individual fibers both as transmitters and as receivers. With a computer model that describes the diffusive light propagation, optical dosimetry is under development, The system has been tested in an experimental animal tumor model in preparation for clinical work. Currently, delta-aminolevulinic acid is used as a sensitizer, activated by 635-nm radiation from a 2.0-W compact diode laser system. With the availability of future, highly selective drugs absorbing approximately 750 nm, larger tumor volumes should be treatable, and surrounding, sensitive normal tissue should be spared.
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