title: 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: Department of Dermatology, Sahlgrenska Academy, University of Gothenburg, Sweden. carin.sandberg@vgregion.se
authors: Carin
authors: C
authors: Sandberg
authors: John
authors: J
authors: Paoli
authors: Martin
authors: M
authors: Gillstedt
authors: Christina B
authors: CB
authors: Halldin
authors: Olle
authors: O
authors: Larkö
authors: Ann-Marie
authors: AM
authors: Wennberg
authors: Marica B
authors: MB
authors: Ericson