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In vivo measurement of parameters of dosimetric importance during interstitial photodynamic therapy of thick skin tumors

Johansson, Ann LU ; Johansson, Thomas ; Soto Thompson, Marcelo LU ; Bendsöe, Niels LU ; Svanberg, Katarina LU ; Svanberg, Sune LU and Andersson-Engels, Stefan LU (2006) In Journal of Biomedical Optics 11.
Abstract
A system for interstitial photodynamic therapy is used in the treatment of thick skin tumors. The system allows simultaneous measurements of light fluence rate, sensitizer fluorescence, and tissue oxygen saturation by using the same fibers as for therapeutic light delivery. Results from ten tumor treatments using delta-aminolevulinic acid (ALA)-induced protoporphyrin IX show a significant, treatment-induced increase in tissue absorption at the therapeutic wavelength, and rapid sensitizer photobleaching. The changes in oxy- and deoxyhemoglobin content are monitored by means of near-infrared spectroscopy, revealing a varying tissue oxygenation and significant changes in blood volume during treatment. These changes are consistent with the... (More)
A system for interstitial photodynamic therapy is used in the treatment of thick skin tumors. The system allows simultaneous measurements of light fluence rate, sensitizer fluorescence, and tissue oxygen saturation by using the same fibers as for therapeutic light delivery. Results from ten tumor treatments using delta-aminolevulinic acid (ALA)-induced protoporphyrin IX show a significant, treatment-induced increase in tissue absorption at the therapeutic wavelength, and rapid sensitizer photobleaching. The changes in oxy- and deoxyhemoglobin content are monitored by means of near-infrared spectroscopy, revealing a varying tissue oxygenation and significant changes in blood volume during treatment. These changes are consistent with the temporal profiles of the light fluence rate at the therapeutic wavelength actually measured. We therefore propose the observed absorption increase to be due to treatment-induced deoxygenation in combination with changes in blood concentration within the treated volume. A higher rate of initial photobleaching is found to correlate with a less pronounced increase in tissue absorption. Based on the measured signals, we propose how real-time treatment supervision and feedback can be implemented. Simultaneous study of the fluence rate, sensitizer fluorescence, and local tissue oxygen saturation level may contribute to the understanding of the threshold dose for photodynamic therapy. (c) 2006 Society of Photo-Optical Instrumentation Engineers. (Less)
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author
; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
protoporphyrin IX fluorescence, photobleaching, delta-aminolevulinic acid, absorption, photodynamic therapy, spectroscopy
in
Journal of Biomedical Optics
volume
11
article number
39
publisher
SPIE
external identifiers
  • wos:000239583600032
  • scopus:33748461809
ISSN
1083-3668
DOI
10.1117/1.2204027
language
English
LU publication?
yes
id
d3fbbd39-fadc-4845-b24a-b6f31d71bf25 (old id 398410)
date added to LUP
2016-04-01 11:51:48
date last changed
2021-10-06 04:37:08
@article{d3fbbd39-fadc-4845-b24a-b6f31d71bf25,
  abstract     = {A system for interstitial photodynamic therapy is used in the treatment of thick skin tumors. The system allows simultaneous measurements of light fluence rate, sensitizer fluorescence, and tissue oxygen saturation by using the same fibers as for therapeutic light delivery. Results from ten tumor treatments using delta-aminolevulinic acid (ALA)-induced protoporphyrin IX show a significant, treatment-induced increase in tissue absorption at the therapeutic wavelength, and rapid sensitizer photobleaching. The changes in oxy- and deoxyhemoglobin content are monitored by means of near-infrared spectroscopy, revealing a varying tissue oxygenation and significant changes in blood volume during treatment. These changes are consistent with the temporal profiles of the light fluence rate at the therapeutic wavelength actually measured. We therefore propose the observed absorption increase to be due to treatment-induced deoxygenation in combination with changes in blood concentration within the treated volume. A higher rate of initial photobleaching is found to correlate with a less pronounced increase in tissue absorption. Based on the measured signals, we propose how real-time treatment supervision and feedback can be implemented. Simultaneous study of the fluence rate, sensitizer fluorescence, and local tissue oxygen saturation level may contribute to the understanding of the threshold dose for photodynamic therapy. (c) 2006 Society of Photo-Optical Instrumentation Engineers.},
  author       = {Johansson, Ann and Johansson, Thomas and Soto Thompson, Marcelo and Bendsöe, Niels and Svanberg, Katarina and Svanberg, Sune and Andersson-Engels, Stefan},
  issn         = {1083-3668},
  language     = {eng},
  publisher    = {SPIE},
  series       = {Journal of Biomedical Optics},
  title        = {In vivo measurement of parameters of dosimetric importance during interstitial photodynamic therapy of thick skin tumors},
  url          = {https://lup.lub.lu.se/search/ws/files/2676426/2370304.pdf},
  doi          = {10.1117/1.2204027},
  volume       = {11},
  year         = {2006},
}