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Proceedings Paper

Enhancement of 5-aminolevulinic-acid-induced photodynamic therapy using light-dose fractionation and iron-chelating agents
Author(s): Alison Curnow; Matthew J. Postle-Hacon; Alexander J. MacRobert; Stephen G. Bown
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Paper Abstract

Preliminary clinical studies of 5-aminolaevulinic acid (ALA) induced photodynamic therapy (PDT) with the maximum tolerated oral dose (60 mg/kg), currently appear to only produce limited amounts of necrosis. We have studied ways of increasing this effect without increasing the drug dose. In normal, female, Wistar rats we have found it possible to increase the area of necrosis produced in the colon substantially by simply interrupting the light dose (25 J, 635 nm, 100 mW) for a short period of time, while all other variables are kept constant. It is possible to cause up to four times more necrosis with a dose of 200 mg/kg ALA i.v. by introducing a single 150 second interval which splits the light dose into two fractions after 5 J has been delivered. We have found these parameters to be optimal for this dose. Likewise, in the same model, the effect of the iron chelating agent, CP94, was also investigated and we have found it possible to produce three times the area of necrosis with the simultaneous administration of 100 mg/kg CP94 i.v. and 50 mg/kg ALA i.v. We have therefore shown, that it is possible to significantly increase the effects of ALA induced PDT without increasing the administered dose of ALA by utilizing these techniques.

Paper Details

Date Published: 19 May 1998
PDF: 10 pages
Proc. SPIE 3247, Optical Methods for Tumor Treatment and Detections: Mechanisms and Techniques in Photodynamic Therapy VII, (19 May 1998); doi: 10.1117/12.308139
Show Author Affiliations
Alison Curnow, Univ. College London Medical School (United Kingdom)
Matthew J. Postle-Hacon, Univ. College London Medical School (United Kingdom)
Alexander J. MacRobert, Univ. College London Medical School (United Kingdom)
Stephen G. Bown, University College London Medical School (United Kingdom)


Published in SPIE Proceedings Vol. 3247:
Optical Methods for Tumor Treatment and Detections: Mechanisms and Techniques in Photodynamic Therapy VII
Thomas J. Dougherty, Editor(s)

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