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Evaluation of cylindrical diffuser fiber tips for interstitial photodynamic therapy of prostate cancer

Rengstedt, Johan LU (2013) PHYM01 20131
Atomic Physics
Mathematical Physics
Abstract
The aim of this thesis project is to evaluate the performance of cylindrical diffuser fibers in IPDT. Spectracure AB has developed a system for real time monitoring of dose parameters during IPDT treatment of prostate cancer using bare-end fiber tips. One of the parameters that is monitored is the effective attenuation coefficient, mu_{eff}, and the goal of this thesis is to study how well this parameter can be evaluated with cylindrical fibers. For this purpose a digital 3D model with a FEM solver is used to simulate experimental data and an evaluation program is implemented in Matlab. This program assesses the optical properties at each fiber given the simulated fluence rate measured in the digital model. The program is shown to work... (More)
The aim of this thesis project is to evaluate the performance of cylindrical diffuser fibers in IPDT. Spectracure AB has developed a system for real time monitoring of dose parameters during IPDT treatment of prostate cancer using bare-end fiber tips. One of the parameters that is monitored is the effective attenuation coefficient, mu_{eff}, and the goal of this thesis is to study how well this parameter can be evaluated with cylindrical fibers. For this purpose a digital 3D model with a FEM solver is used to simulate experimental data and an evaluation program is implemented in Matlab. This program assesses the optical properties at each fiber given the simulated fluence rate measured in the digital model. The program is shown to work well in the ideal homogeneous case with with normal optical properties, where the error is only 0.35 % between assessed mu_{eff} and the actual mu_{eff} from the simulated experimental data.

Normal errors in fiber positioning impose an error of about 4.48% between evaluated and actual mu_{eff}. When a heterogeneous tissue model is used to mimic the true condition in vivo, larger errors are seen. In the worst case giving an error of 22.7% between evaluated and actual mu_{eff}. It was otherwise difficult to draw definite conclusions from the results of the evaluation under heterogeneous conditions. Further tests on in-vivo and incorporating the cylindrical diffusers in the complete SpectraCure system would give a more conclusive answer. It is shown however that it is possible to implement an evaluation software for cylindrical diffuser fibers, that it is possible to obtain a good light distribution profile and that it is accurate in the ideal case. (Less)
Please use this url to cite or link to this publication:
author
Rengstedt, Johan LU
supervisor
organization
course
PHYM01 20131
year
type
H2 - Master's Degree (Two Years)
subject
keywords
IPDT, prostate cancer, cylindrical diffuser, medical optics, Spectracure, photodynamic therapy, tissue optics, PDT, photosensitizer
language
English
id
4279665
date added to LUP
2014-01-31 11:09:51
date last changed
2015-12-14 13:32:33
@misc{4279665,
  abstract     = {The aim of this thesis project is to evaluate the performance of cylindrical diffuser fibers in IPDT. Spectracure AB has developed a system for real time monitoring of dose parameters during IPDT treatment of prostate cancer using bare-end fiber tips. One of the parameters that is monitored is the effective attenuation coefficient, mu_{eff}, and the goal of this thesis is to study how well this parameter can be evaluated with cylindrical fibers. For this purpose a digital 3D model with a FEM solver is used to simulate experimental data and an evaluation program is implemented in Matlab. This program assesses the optical properties at each fiber given the simulated fluence rate measured in the digital model. The program is shown to work well in the ideal homogeneous case with with normal optical properties, where the error is only 0.35 % between assessed mu_{eff} and the actual mu_{eff} from the simulated experimental data.

Normal errors in fiber positioning impose an error of about 4.48% between evaluated and actual mu_{eff}. When a heterogeneous tissue model is used to mimic the true condition in vivo, larger errors are seen. In the worst case giving an error of 22.7% between evaluated and actual mu_{eff}. It was otherwise difficult to draw definite conclusions from the results of the evaluation under heterogeneous conditions. Further tests on in-vivo and incorporating the cylindrical diffusers in the complete SpectraCure system would give a more conclusive answer. It is shown however that it is possible to implement an evaluation software for cylindrical diffuser fibers, that it is possible to obtain a good light distribution profile and that it is accurate in the ideal case.},
  author       = {Rengstedt, Johan},
  keyword      = {IPDT,prostate cancer,cylindrical diffuser,medical optics,Spectracure,photodynamic therapy,tissue optics,PDT,photosensitizer},
  language     = {eng},
  note         = {Student Paper},
  title        = {Evaluation of cylindrical diffuser fiber tips for interstitial photodynamic therapy of prostate cancer},
  year         = {2013},
}