Photodynamic therapy of early squamous cell carcinoma with tetra(m-hydroxyphenyl)chlorin: optimal drug-light interval.

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State: Public
Version: Final published version
Serval ID
serval:BIB_AA55E2A3B65C
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Photodynamic therapy of early squamous cell carcinoma with tetra(m-hydroxyphenyl)chlorin: optimal drug-light interval.
Journal
British journal of cancer
Author(s)
Andrejevic-Blant S., Hadjur C., Ballini J.P., Wagnières G., Fontolliet C., van den Bergh H., Monnier P.
ISSN
0007-0920 (Print)
ISSN-L
0007-0920
Publication state
Published
Issued date
1997
Peer-reviewed
Oui
Volume
76
Number
8
Pages
1021-1028
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Abstract
The optimal drug-light interval for effective photodynamic therapy (PDT) of early squamous cell carcinomas was evaluated with tetra(m-hydroxyphenyl)chlorin (mTHPC) by means of two complementary modalities: irradiation tests and ex vivo fluorescence microscopy. A Syrian hamster cheek pouch tumour model was used in these experiments. Photodynamic therapy on both tumour-bearing and contralateral healthy cheek pouch mucosae was performed at 650 nm and 514 nm. Light doses of 12 J cm(-2) were delivered at a light dose rate of 150 mW cm(-2) and light doses of 80 J cm(-2) were delivered at a light dose rate of 100 mW cm(-2) respectively, at these two wavelengths, between 6 h and 12 days after the injection of 0.5 mg kg(-1) body weight mTHPC. Two histologically different types of tissue damage were observed: first, a non-selective and non-specific ischaemic vascular necrosis for the cases in which PDT took place during the first 48 h after the injection of the dye and, second, tissue-specific PDT damage, as a coagulation necrosis, when PDT took place more than 72 h after injection of the dye. The time-dependent biodistribution of mTHPC investigated by fluorescence microscopy shows a weak and non-significant difference in relative fluorescence intensities between early SCC and healthy mucosae. Up to 2 days after the injection, the drug is mainly localized in the endothelial cells of the blood vessels. After this period, the dye accumulates in the squamous epithelia with a concentration peaking at 4 days. At all time points, a weak fluorescence intensity is observed in the underlying lamina propria and striated muscle. The information obtained from these studies could well be relevant to clinical trials as it suggests that time delays between 4 and 8 days after i.v. injection should be optimal for PDT of early malignancies in hollow organs.

Keywords
Animals, Antineoplastic Agents/pharmacokinetics, Antineoplastic Agents/pharmacology, Carcinoma in Situ/drug therapy, Carcinoma in Situ/metabolism, Carcinoma in Situ/pathology, Carcinoma, Squamous Cell/drug therapy, Carcinoma, Squamous Cell/metabolism, Carcinoma, Squamous Cell/pathology, Cheek, Cricetinae, Drug Administration Schedule, Light, Mesocricetus, Mesoporphyrins/pharmacokinetics, Mesoporphyrins/pharmacology, Microscopy, Fluorescence, Mouth Neoplasms/drug therapy, Mouth Neoplasms/metabolism, Mouth Neoplasms/pathology, Photochemotherapy, Radiation-Sensitizing Agents/pharmacokinetics, Radiation-Sensitizing Agents/pharmacology, Tissue Distribution
Pubmed
Web of science
Open Access
Yes
Create date
29/01/2008 18:34
Last modification date
20/08/2019 15:14
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