Color-imaging histodiagnostic approach for cancer

We contrived a color-imaging manner in histodiagnosis of cancer and evaluated its clinical feasibility and significance. Cancer was microscopically detected by identifying specific reddish pink fluorescence emitted from cancer cells under blue light irradiation, which was based on a photodynamic diagnosis (PDD) theory. Aminolevulinic acid (ALA) was used to treat the histologic samples. Three different types of tumor cell lines were used as neoplastic models. In in vitro, we ascertained that each tumor cell treated with ALA-contained medium solution emitted red fluorescence under blue light. In clinical studies, freshly harvested specimens from cancer patients during surgical operations were directly soaked into ALA-containing culture medium, which were incubated at 37°C for a certain minutes. Then microscopically observed under the blue light beam. The samples radiated reddish pink fluorescence were regarded as cancer. Each model cell emitted pink fluorescence by treating with 1% ALA/cell culture medium at 37°C for 30 min. Non-viable and/or apoptotic cells showed no fluorescence under the same conditions. Clinically harvested cancer regions treated with the ALA-medium solution also showed pink fluorescence. We could discriminate malignant change of the samples within 30-60 minutes without preparing frozen sections for rapid diagnoses. This simple method suggested clinically useful tool in a rapid cancer diagnosis.