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Medical Laser-Induced Thermotherapy - Models and Applications

Sturesson, Christian LU (1998) In Lund Reports in Atomic Physics LRAP-235.
Abstract
Heat has long been utilised as a therapeutic tool in medicine. Laser-induced thermotherapy aims at achieving the local destruction of lesions, relying on the conversion of the light absorbed by the tissue into heat. In interstitial laser-induced thermotherapy, light is focused into thin optical fibres, which are placed deep into the tumour mass. The objective of this work was to increase the understanding of the physical and biological phenomena governing the response to laser-induced thermotherapy, with special reference to treatment of liver tumours and benign prostatic hyperplasia. Mathematical models were used to calculate the distribution of light absorption and the subsequent temperature distribution in laser-irradiated tissues. The... (More)
Heat has long been utilised as a therapeutic tool in medicine. Laser-induced thermotherapy aims at achieving the local destruction of lesions, relying on the conversion of the light absorbed by the tissue into heat. In interstitial laser-induced thermotherapy, light is focused into thin optical fibres, which are placed deep into the tumour mass. The objective of this work was to increase the understanding of the physical and biological phenomena governing the response to laser-induced thermotherapy, with special reference to treatment of liver tumours and benign prostatic hyperplasia. Mathematical models were used to calculate the distribution of light absorption and the subsequent temperature distribution in laser-irradiated tissues. The models were used to investigate the influence on the temperature distribution of a number of different factors, such as the design of the laser probe, the number of fibres, the optical properties of the tissue, the duration of irradiation, blood perfusion and boundary conditions. New results concerning transurethral microwave thermotherapy were obtained by incorporating the distribution of absorbed microwaves into the model. Prototypes of new laser applicators for anatomically correct treatment of benign prostatic hyperplasia were developed and tested ex vivo. Experimental work on liver tumours pointed to the importance of eliminating the blood flow in the liver during treatment to reduce convective heat loss. In addition, it was shown that hepatic inflow occlusion during treatment increased the thermal sensitivity of tumour tissue. The dynamic influence of interstitial laser thermotherapy on liver perfusion was investigated using interstitial laser Doppler flowmetry. Vessel damage after the combined treatment of laser-induced heat treatment and photodynamic therapy was studied. (Less)
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author
opponent
  • Professor van Gemert, Martin J.C., Academic Medical Centre, Amsterdam, The Netherlands
organization
publishing date
type
Thesis
publication status
published
subject
keywords
blood perfusion, mathematical modelling, liver tumours, Atomic and molecular physics, benign prostatic hyperplasia, Atom- och molekylärfysik, Fysicumarkivet A:1998:Sturesson, hyperthermia, Coagulation, tissue optical properties
in
Lund Reports in Atomic Physics
volume
LRAP-235
pages
210 pages
publisher
Department of Physics, Lund University
defense location
Lecture hall B, Department of Physics, Sölvegatan 14, Lund, Sweden
defense date
1998-10-24 10:15
external identifiers
  • Other:LUTFD2/(TFAF-1037)/1-83/(1998)
ISBN
91-628-3134-8
language
English
LU publication?
yes
id
6fac597a-8da1-4fb6-bae3-a37b56ab1bb0 (old id 38965)
date added to LUP
2007-10-01 15:42:07
date last changed
2016-09-19 08:45:15
@misc{6fac597a-8da1-4fb6-bae3-a37b56ab1bb0,
  abstract     = {Heat has long been utilised as a therapeutic tool in medicine. Laser-induced thermotherapy aims at achieving the local destruction of lesions, relying on the conversion of the light absorbed by the tissue into heat. In interstitial laser-induced thermotherapy, light is focused into thin optical fibres, which are placed deep into the tumour mass. The objective of this work was to increase the understanding of the physical and biological phenomena governing the response to laser-induced thermotherapy, with special reference to treatment of liver tumours and benign prostatic hyperplasia. Mathematical models were used to calculate the distribution of light absorption and the subsequent temperature distribution in laser-irradiated tissues. The models were used to investigate the influence on the temperature distribution of a number of different factors, such as the design of the laser probe, the number of fibres, the optical properties of the tissue, the duration of irradiation, blood perfusion and boundary conditions. New results concerning transurethral microwave thermotherapy were obtained by incorporating the distribution of absorbed microwaves into the model. Prototypes of new laser applicators for anatomically correct treatment of benign prostatic hyperplasia were developed and tested ex vivo. Experimental work on liver tumours pointed to the importance of eliminating the blood flow in the liver during treatment to reduce convective heat loss. In addition, it was shown that hepatic inflow occlusion during treatment increased the thermal sensitivity of tumour tissue. The dynamic influence of interstitial laser thermotherapy on liver perfusion was investigated using interstitial laser Doppler flowmetry. Vessel damage after the combined treatment of laser-induced heat treatment and photodynamic therapy was studied.},
  author       = {Sturesson, Christian},
  isbn         = {91-628-3134-8},
  keyword      = {blood perfusion,mathematical modelling,liver tumours,Atomic and molecular physics,benign prostatic hyperplasia,Atom- och molekylärfysik,Fysicumarkivet A:1998:Sturesson,hyperthermia,Coagulation,tissue optical properties},
  language     = {eng},
  pages        = {210},
  publisher    = {ARRAY(0xb24b230)},
  series       = {Lund Reports in Atomic Physics},
  title        = {Medical Laser-Induced Thermotherapy - Models and Applications},
  volume       = {LRAP-235},
  year         = {1998},
}