1.
Andersson-Engels, Stefan, et al.
(författare)
Integrated system for interstitial photodynamic therapy
2002
Ingår i: Advanced Optical Devices, Technologies, and Medical Applications. - : SPIE. - 0277-786X .- 1996-756X. ; 5123, s. 293-302
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.
2.
Johansson, Thomas, et al.
(författare)
Feasibility study of a system for combined light dosimetry and interstitial photodynamic treatment of massive tumors
2002
Ingår i: Applied Optics. - 2155-3165. ; 41:7, s. 1462-1468
Tidskriftsartikel (refereegranskat) 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.
3.
Svanberg, Katarina
(författare)
Diagnostics and treatment of human malignant tumours using laser based techniques
2002
Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 1996-756X .- 0277-786X. ; 5226, s. 387-393
Konferensbidrag (refereegranskat) abstract
Laser-induced fluorescence is a technique for optical tissue characterisation. It has a real-time capability and as the excitation light and the fluorescence emission are transmitted through optical fibres the technique is compatible to various kinds of endoscopes for hollow organ investigation. The tissue fluorescence itself with the emission from the endogenous chromophores or enhanced with exogenously administered tumour seeking agents are employed. Contrast functions are beeing developed for optimal tumour demarcation. Photodynamic therapy is a selective therapy for certain types of malignancies. In particular the topical application of a sensitising agent has been employed for human skin malignancies. Clinical examples are both from the detection and the treatment side.
