Spectrophotometric photodynamic detection involving extracorporeal treatment with hexaminolevulinate for bladder cancer cells in voided urine.

PURPOSE: To evaluate the feasibility of hexaminolevulinate (HAL) for the photodynamic detection of cancer cells in voided urine. METHODS: This study included 50 patients with bladder cancer that was confirmed histologically after transurethral resection (bladder cancer group) and 50 outpatients without a history of urothelial carcinoma or cancer-related findings (no malignancy group). One third of the voided urine samples were incubated with aminolevulinic acid (ALA-treated samples), one third were incubated with HAL (HAL-treated samples), and the remaining samples were incubated without treatment (untreated samples). For detecting cellular protoporphyrin IX levels, the intensity of the samples at the excitation wavelength of 405 nm was measured using a spectrophotometer. The difference between the intensity of the ALA-treated or HAL-treated samples and the untreated samples at 635 nm was calculated. RESULTS: HAL-induced fluorescence cytology (HFC) showed that the difference was significantly higher in patients with high-grade tumors than in those with low-grade tumors (p = 0.0003) and the difference was significantly higher in patients with low-grade tumors than in those without a history of urothelial carcinoma or cancer-related findings (p = 0.021). The areas under the receiver operating characteristic curves of ALA-induced fluorescence cytology (AFC) and HFC were 0.77 and 0.81, respectively. The AUC of HFC was significantly higher than that of AFC (p < 0.0001). The overall sensitivity values for conventional cytology, AFC, and HFC were 49, 74, and 74%, respectively. The overall specificity values for AFC and HFC were 70 and 94%, respectively. CONCLUSIONS: Spectrophotometric photodynamic detection involving extracorporeal treatment with HAL for bladder cancer cells in voided urine showed high accuracy. This bladder cancer detection method is easy and cost-effective, and has the potential for clinical use.