We have applied the fluorescence spectral analysis to detection of protoporphyrin-IX (Pp-IX) quantitatively in the transplanted squamous cell carcinoma (SCC) tissue and intraoperative brain astrocytoma (glioblastoma) tissue after administration of 5-aminolevulinic acid (5-ALA). We confirmed the coincidence with emission spectra of Pp-IX incorporated into the tumor tissues (cryo-sections) and the standard Pp-IX in the micellar solution. It has used a calibration curve which the fluorescence intensity of Pp-IX against the known concentration of standard Pp-IX. From the fluorescence detection method, it was found that the longer alkyl-chain length (methyl- and hexyl-) 5-ALA induced much Pp-IX in the SCC tissue, furthermore, an ultrasound treatment enhanced the uptake of Pp-IX during the topical administration of 5-ALA derivatives. In the case of intraoperative observation for the fluorescence intensity of Pp-IX in the brain astrocytoma tissue, this quantitative detection in the cryo-section demonstrated the intraoperative observation for the fluorescence intensities (-, +/-, +, ++, +++) diagnosis was correlated closely with the grades of astrocytoma, which intensity increased exponentially with the grades. In future, the fluorescence diagnosis of Pp-IX in the tumor will he very useful for other clinical diagnosis of tumor using 5-ALA.

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