Fluorescence diagnostics of basal cell carcinomas comparing methyl-aminolaevulinate and aminolaevulinic acid and correlation with visual clinical tumour size.

Abstract

Fluorescence diagnostics based on aminolaevulinic acid (ALA) fluorescence has been suggested as an in vivo pre-surgical tool for tumour demarcation. We performed fluorescence diagnostics of 35 basal cell carcinomas (BCCs) undergoing photodynamic therapy (PDT) using methyl-aminolaevulinate (MAL). In addition, a semi-automated thresholding algorithm was implemented to detect the potential tumour region. The mean tumour fluorescence contrast was found to be 1.65 ± 0.06 during the first MAL-PDT session, and increased to 1.84 ± 0.07 at the second treatment (p < 0.01). This could imply that disruption of the skin barrier and inflammatory responses after the first session of PDT led to higher accumulation of proto-porphyrin IX during the second session of PDT. The tumour areas detected based on fluorescence in small BCCs (< 1 cm(2)) were in general (n = 18/23) larger than the visual clinical tumour size. In addition, the fluorescence contrast using MAL (1.65 ± 0.06) was found to be significantly higher (p<10(-4)) than the contrast (data from previous study) after application of ALA (1.20 ± 0.06). Thus, MAL generally provides higher tumour contrast than ALA in BCCs, and should be preferred for use in fluorescence diagnostics. Correlation between fluorescence, lack of treatment response and/or pain was not observed.

• Authors: Carin Sandberg, John Paoli, Martin Gillstedt, Christina B Halldin, Olle Larkö, Ann-Marie Wennberg, Marica B Ericson
• Journal: Acta dermato-venereologica (Acta Derm Venereol) Vol. 91 Issue 4 Pg. 398-403 (Jun 2011) ISSN: 1651-2057 [Electronic] Sweden
• PMID: 21597674 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Photosensitizing Agents
• methyl 5-aminolevulinate
• Aminolevulinic Acid

Topics

• Adult
• Aged
• Aged, 80 and over
• Algorithms
• Aminolevulinic Acid (adverse effects, analogs & derivatives, therapeutic use)
• Automation, Laboratory
• Carcinoma, Basal Cell (diagnosis, pathology, therapy)
• Female
• Fluorescence
• Humans
• Image Interpretation, Computer-Assisted
• Male
• Middle Aged
• Photochemotherapy (adverse effects)
• Photosensitizing Agents (adverse effects, therapeutic use)
• Predictive Value of Tests
• Skin Neoplasms (diagnosis, pathology, therapy)
• Sweden
• Treatment Outcome
• Tumor Burden