| 31. |
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| 32. |
- Andersson-Engels, Stefan, et al.
(författare)
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In vivo luminescence imaging and tomography using upconverting nanoparticles as contrast agents
- 2012
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Ingår i: 2012 Asia Communications and Photonics Conference. - 2162-108X. ; , s. 2-3
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Konferensbidrag (refereegranskat)abstract
- Upconverting nanoparticles have recently drawn increasingly attention as contrast agents for optical bioimaging. They enable autofluorescence-free imaging within the tissue optical window, and improved spatial resolution as compared to conventional fluorescence-based contrast agents. (C) 2012 Optical Society of America
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| 33. |
- Andersson-Engels, Stefan, et al.
(författare)
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Integrated system for interstitial photodynamic therapy
- 2003
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 5142, s. 42-49
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Konferensbidrag (refereegranskat)abstract
- A novel photodynamic therapy system based on interstitial illumination using multiple fibres is under development. The aim with this system is to enable treatment of large tumour volumes and also to utilise real-time measurements to allow on-line dosimetry. Important dosimetric parameters to measure are light fluence rate, sensitizer fluorescence intensity and local blood oxygenation. A construction which allows all functions to be readily performed with a single system is presented. We believe that interstitial PDT utilising this technique may be attractive in many clinical situations.
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| 34. |
- Andersson-Engels, Stefan, et al.
(författare)
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Integrated system for interstitial photodynamic therapy
- 2002
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Ingår i: Advanced Optical Devices, Technologies, and Medical Applications. - : SPIE. - 0277-786X .- 1996-756X. ; 5123, s. 293-302
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Konferensbidrag (refereegranskat)abstract
- To develop PDT beyond treatment of thin superficial tumours, to also be an efficient treatment alternative for deeply located and/or thick tumours, a system based on interstitial illumination using multiple fibres has been developed. Conditions that could benefit from such a treatment modality are for instance malignant brain tumours and tumours in the oral cavity. In interstitial PDT one needs to use multiple fibres for light delivery in order to allow treatments of tumours larger than a few millimetres in diameter. Our system consists of a laser light source, a beam-splitting system dividing the light into three or six output fibres and a custom-made dosimetry programme. The concept is then to use these fibres not only for delivering the treatment light but also to measure parameters of interest for the treatment outcome. The fluence rate of the light emitted by each fibre is measured at the positions of the other fibre tips. From these results the light dose at all positions could be recalculated. Changes in optical properties as well as bleaching and concentration of the photosensitizer during the treatment could be monitored and compensated for in the dosimetry. Tumours have been treated both in experimental studies and in patients with thick superficial Basal Cell Carcinomas. Almost all treated skin lesions responded with complete response.
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| 35. |
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| 36. |
- Andersson-Engels, Stefan, et al.
(författare)
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Laser-induced Fluorescence In Malignant and Normal Tissue of Rats Injected With Benzoporphyrin Derivative
- 1993
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Ingår i: Photochemistry and Photobiology. - : Wiley. - 0031-8655 .- 1751-1097. ; 57:6, s. 978-983
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Tidskriftsartikel (refereegranskat)abstract
- Laser-induced fluorescence was used to characterize the localization of intravenously administered benzoporphyrin derivative-monoacid (BPD-MA) 3 h postinjection in different rat tissue types, including an induced experimental malignant tumor. A comparison of the fluorescence properties and the demarcation potential between the newer sensitizer BPD-MA and four other substances, hematoporphyrin (HP), polyhematoporphyrin ester (PHE), tetrasulfonated phthalocyanine (TSPc) and the commercially available Photofrin earlier investigated, is included. The fluorescence light was induced with a nitrogen laser, emitting at 337 nm. The fluorescence spectrum in the region 380-750 nm was analyzed by a polychromator equipped with a diode array detector. The demarcation potential between tumor and surrounding tissue in terms of fluorescence signal for the tumor model used was 2:1 for BPD-MA. In comparison with the other drugs, HP shows about the same demarcation potential, whereas Photofrin and PHE exhibit about 3 times better and TSPc about 1.5 times better demarcation. By also employing the endogenous tissue fluorescence signature the contrast was enhanced by a factor of about 2 for each of the five drugs.
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| 37. |
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| 38. |
- Andersson-Engels, Stefan, et al.
(författare)
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Laser-induced fluorescence used in localizing atherosclerotic lesions
- 1989
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Ingår i: Lasers in Medical Science. - 0268-8921. ; 4:3, s. 171-181
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated laser-induced fluorescence frompost mortem human arteries in order to find spectroscopic properties allowing discrimination between normal and atherosclerotic vessel wall. A pulsed nitrogen laser emitting light at a wavelength of 337.1 nm was used as an excitation source. The fluorescence spectrum from 370 to 700 nm was captured and analysed by an optical multichannel analyser. Dimensionless contrast functions were formed by using characteristic spectral features at 390, 415, 480, 580 and 600 nm. All samples were investigated in scans across a region where normal as well as diseased vessel wall appeared. The types of plaque were histopathologically divided into four groups, of which three could be singled out using one or more of our spectroscopic criteria. We also investigated the different layers of the normal and diseased vessel wall in order to determine the various contributions to the fluorescence signal. Furthermore, plasma emission spectra were recorded while ablating the normal as well as the diseased vessel wall with an excimer laser, emitting radiation at 308 nm, thus detecting the change in spectral characteristics during the ablation process down into deeper layers.
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| 39. |
- Andersson-Engels, Stefan, et al.
(författare)
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Laser Spectroscopy in Medical Diagnostics
- 1992
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Ingår i: Photodynamic Therapy: Basic Principles and Clinical Applications. - 0824786807 ; , s. 387-424
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Bokkapitel (refereegranskat)
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| 40. |
- Andersson-Engels, Stefan, et al.
(författare)
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Malignant-tumor and Atherosclerotic Plaque Diagnosis Using Laser-induced Fluorescence
- 1990
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Ingår i: IEEE Journal of Quantum Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9197. ; 26:12, s. 2207-2217
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Tidskriftsartikel (refereegranskat)abstract
- A review of tissue diagnostics using laser-induced fluorescence is given with illustrations chosen from work performed by the Lund group. Two major topics are considered: the demarcation of malignant tumors from normal surrounding tissue and the identification of atherosclerotic regions in arteries. Specific fluorescence from injected agents as well as tissue natural autofluorescence is discussed. Steady-state, as well as time-resolved fluorescence can be utilized. Furthurmore, original data showing immunity to blood interference in artery monitoring are presented. Finally, imaging techniques for diseased tissue real-time visualization are discussed and illustrated.
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