The kinetics of protoporphyrin fluorescence during ALA-PDT in human malignant skin tumors

Arie Orenstein, Genady Kostenich, Zvi Malik

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    51 Scopus citations


    Fluorescence monitoring during photodynamic therapy (PDT) with the use of topical 5-aminolevulinic acid (ALA) was carried out in patients bearing superficial and nodular basal cell carcinomas (BCC), squamous cell carcinomas (SCC) and Kaposi's sarcomas. A new diagnostic-therapeutic system based on an incoherent CW light source was used for fluorescence spectral measurements and imaging. The results showed that photoirradiation reduced ALA-induced protoporphyrin IX (PP) fluorescence in all tumors. The rate of PP photobleaching in superficial BCC and SCC tumors was significantly higher than in large nodular BCC tumors. The results showed that the differences in kinetics of fluorescence reduction could be attributed to the tumor thickness. One hour after photoirradiation with a light dose of 170 J/cm2 a phenomenon of re-appearance and recovery of PP fluorescence was observed in the large deeply penetrating BCC tumors and Kaposi's sarcoma lesions. In such cases an additional light treatment was performed. The results of the study demonstrated that fluorescence monitoring is very appropriate for the definition of an optimal ALA-PDT clinical protocol.

    Original languageEnglish
    Pages (from-to)229-234
    Number of pages6
    JournalCancer Letters
    Issue number2
    StatePublished - 9 Dec 1997

    Bibliographical note

    Funding Information:
    We wish to thank ESC Medical Systems for technical and financial support of this research. We also thank Mrs J. Hanania for assistance in preparing the manuscript.


    • Aminolevulinic acid
    • Basal cell carcinoma
    • Fluorescence monitoring
    • Kaposi's sarcoma
    • Patients
    • Photodynamic therapy
    • Squamous cell carcinoma


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