Unfortunately in the Summary we are not told the histological nature of the BCCs on the face. It is the infiltrative and morphoeic lesions we are most interested in as they are the most difficult to accurately define.IMCC
Photodetection of basal cell carcinoma using methyl 5-aminolaevulinate-induced protoporphyrin IX based on fluorescence image analysis
Authors: Won, Y.1; Hong, S. H.1; Yu, H. Y.2; Kwon, Y. H.; Yun, S. J.; Lee, S. C.; Lee, J. B.
Source: Clinical & Experimental Dermatology, Volume 32, Number 4, July 2007 , pp. 423-429(7)
Publisher: Blackwell Publishing
Abstract:
Summary Background.
The preferential accumulation of 5-aminolaevulinic acid (ALA)-induced protoporphyrin IX (PpIX) in neoplastic cells supports its potential use in the photodetection of porphyrin fluorescence in tumour cells. Hence, epithelial tumours, including basal cell carcinoma (BCC), might be visualized using the fluorescence of selectively accumulated ALA-induced PpIX. Aim.
In this study, we evaluated the clinical efficacy of PpIX fluorescence images using fluorescence image analysis (FIA) to define the lateral border between the tumour and tumour-free areas of facial BCC. Methods.
FIA was used to define the lateral border between the tumour and tumour-free areas on red fluorescence images induced by the topical application of methyl 5-aminolaevulinate (MAL) ointment. According to the FIA results, 50 tissue samples, obtained from 10 patients with BCC, were divided into three categories: tumour area (n = 10), suspected tumour area (n = 20) and suspected tumour-free area (n = 20). These tissue samples were evaluated by histopathological examination. The FIA tool marked out the PpIX fluorescence image for defining the lateral border between the BCC tumour and tumour-free areas. Results.
The rate of tumour detection from BCC lesions using PpIX fluorescence with the FIA tool showed a sensitivity of 94.1% and specificity of 82.6%. Conclusion.
These results suggest that MAL-induced PpIX fluorescence imaging using FIA is quite sensitive and specific for detecting tumour and occult tumour in facial BCC lesions. This method of presurgical in vivo imaging is therefore proposed as a useful tool for defining the lateral border between BCC tumour and tumour-free areas
2 comments:
This is an interesting potential new use for Metvix. A few comments:
The study looked at 10 subjects with 7 nodular, 2 infiltrating and 1 mixed (nodular and infiltrating) BCC's, all on the face.
There was no mention of Skin type, however photos appear to depict asian skin.
They used Metvix, which is supposed to be more preferentially taken up by tumour cells than ALA, however they used a 20% formulation.
They only compared with the naked eye, that is, did not use dermoscopy to delineate tumour as is my standard pre-op practice.
The depth of biopsy punches is not indicated, and potentially you could miss a subcutaneous extension of infiltrative BCC if punch is not deep enough.
Thanks Paul for accessing the details of this article. I know Lester is using ultrasound for the same purpose. A larger study would have been helpful. The technique has been described before for extramammary Pagets in the genital areas and seemed to find the small extensions of that tumour.
Post a Comment