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The time-dependent accumulation of protoporphyrin IX fluorescence in nodular basal cell carcinoma following application of methyl aminolevulinate with an oxygen pressure injection device

Paper ID Volume ID Publish Year Pages File Format Full-Text
30659 44495 2012 7 PDF Available
Title
The time-dependent accumulation of protoporphyrin IX fluorescence in nodular basal cell carcinoma following application of methyl aminolevulinate with an oxygen pressure injection device
Abstract

Topical protoporphyrin (PpIX)-induced photodynamic therapy (PDT) relies on the penetration of the prodrug into the skin lesion and subsequent accumulation of the photosensitizer. Methyl aminolevulinate (MAL)-PDT is an established treatment for thinner and superficial non-melanoma skin cancers (NMSCs) but for the treatment of the thicker nodular basal cell carcinoma (nBCC) enhanced penetration of the prodrug is required. This study employed a new higher pressure, oxygen pressure injection (OPI) device, at the time of Metvix® application with a view to enhancing the penetration of MAL into the tumors. Each patient had Metvix® applied to a single nBCC followed by application of a higher pressure OPI device. Following different time intervals (0, 30, 60, 120 or 180 min) the tumors were excised. The maximum depth and area of MAL penetration achieved in each lesion was measured using PpIX fluorescence microscopy. As expected, an increase in the depth of MAL-induced PpIX accumulation and area of tumor sensitized was observed over time; when the Metvix® cream was applied for 0, 30, 60, 120 and 180 min the median depth of PpIX fluorescence was 0%, 21%, 26.5%, 75.5% and 90%, respectively and the median area of tumor sensitized was 0%, 4%, 6%, 19% and 60%, respectively. As the investigation presented here did not include a control arm, the relative depths of fluorescence observed in this study were statistically compared (using the non-parametric Mann Whitney U test) with the results of our previous study where patients had Metvix® cream applied either with or without the standard pressure OPI device. When the higher pressure OPI device was employed compared to without OPI this increase was observed to be greater following 30, 120, and 180 min although overall not significantly (p = 0.835). In addition, no significant difference between the higher pressure OPI device employed here and the previously investigated standard pressure OPI device was observed (p = 0.403). However, when the results for both OPI devices were combined and compared to the standard treatment (no OPI employed) group, although the difference did not reach significance (p = 0.531) a consistent and substantial increase in the depth of PpIX fluorescence was observed, therefore employment of an OPI device during topical MAL-PDT protocols warrants further investigation as a technique for enhancing MAL penetration.

► An oxygen pressure injection device enhanced penetration of the prodrug methyl aminolevulinate. ► Application of Metvix® cream with the device increased depth of protoporphyrin IX accumulation over time. ► Application of Metvix® cream with the device increased area of tumor sensitized over time. ► No significant difference in enhancement between the higher pressure and standard pressure devices was observed. ► Further investigation of the device should be considered when treating thicker lesions with photodynamic therapy.

Keywords
Photodynamic therapy (PDT); Methyl aminolevulinate (MAL); Protoporphyrin IX; Topical; Non-melanoma skin cancer (NMSC)
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The time-dependent accumulation of protoporphyrin IX fluorescence in nodular basal cell carcinoma following application of methyl aminolevulinate with an oxygen pressure injection device
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Photochemistry and Photobiology B: Biology - Volume 117, 5 December 2012, Pages 97–103
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us