Influence of tumour depth, blood absorption and autofluorescence on measurements of exogenous fluorophores in tissue

We investigated the influence of tumour depth and differences in blood concentration and autofluorescence between tumour and normal tissue on the fluorescence of a tumour-localising agent. Carotenoporphyrin, CP(Me)3, was injected into rats and nude mice with intradermal tumours. On the tumours an incision was made, uncovering 2 mm2 of the tumour, and fluorescence measurements, including excitation-emission maps and fluorescence ratios, were made on skin, covered and uncovered tumour. The measured fluorescence ratio in the uncovered tumour showed a three- to tenfold increase compared to the covered tumour. We used a one-dimensional layered tissue model to analyse the data. In conclusion, even with a high tumour-selectivity deeper lying tumours cannot always be detected, particularly if the tumour has a high blood concentration or low autofluorescence intensity.

[1]  J. Kennedy,et al.  The nature of the chromophore responsible for naturally occurring fluorescence in mouse skin. , 1988, Journal of photochemistry and photobiology. B, Biology.

[2]  A E Profio,et al.  Detection of early lung cancer using low dose Photofrin II. , 1990, Chest.

[3]  T. Moore,et al.  Synthesis of carotenoporphyrin models for photosynthetic energy and electron transfer , 1992 .

[4]  T J Flotte,et al.  Ultraviolet laser‐induced fluorescence of colonic tissue: Basic biology and diagnostic potential , 1992, Lasers in surgery and medicine.

[5]  K. Svanberg,et al.  Laser-induced fluorescence in malignant and normal tissue in mice injected with two different carotenoporphyrins. , 1994, British Journal of Cancer.

[6]  T. Moore,et al.  Carotenoporphyrins as selective photodiagnostic agents for tumours. , 1994, British Journal of Cancer.

[7]  S L Jacques,et al.  In vivo autofluorescence of an unpigmented melanoma in mice. Correlation of spectroscopic properties to microscopic structure , 1995, Melanoma research.

[8]  Steven L. Jacques,et al.  In vivo fluorescence spectroscopy and imaging of human skin tumors. , 1995 .

[9]  Ashleyj . Welch,et al.  Optical-Thermal Response of Laser-Irradiated Tissue , 1995 .

[10]  H Stepp,et al.  Detection of early bladder cancer by 5-aminolevulinic acid induced porphyrin fluorescence. , 1996, The Journal of urology.

[11]  S L Jacques,et al.  Light transport in tissue: Accurate expressions for one‐dimensional fluence rate and escape function based upon Monte Carlo simulation , 1996, Lasers in surgery and medicine.

[12]  W Verkruysse,et al.  Wavelengths for port wine stain laser treatment: influence of vessel radius and skin anatomy. , 1997, Physics in medicine and biology.

[13]  K. Svanberg,et al.  Laser-induced fluorescence studies of the biodistribution of carotenoporphyrins in mice. , 1997, British Journal of Cancer.