CLINICAL EXPERIENCE WITH TRANSURETHRAL RESECTION OF BLADDER TUMOR (TUR-Bt) GUIDED BY PHOTODYNAMIC DIAGNOSIS (PDD)

Abstract

(Purpose) To report our clinical experience regarding transurethral resection of bladder tumor (TUR-Bt) guided by photodynamic diagnosis (PDD) with intravesical instillations of 5-aminolevulinic acid (ALA) and to assess the usefulness of the therapeutic method.
(Materials and methods) TUR-Bt guided by PDD was performed in 57 patients of which 47 were men and 10 women with a median age of 74.3 years (range 45-90), 36 were primary cases and 21 were recurrent cases with non-muscle invasive bladder cancer. Two to two and half hours prior to endoscopy 1.5 g ALA dissolved in 50 ml of 8.4% sodium hydrogen carbonate (NaHCO₃) solution was instilled intravesically. For fluorescence excitation a blue light source (D-LIGHT System, Karl Storz Endoscopy Japan K.K.) was used. The tumorous lesions under white light guidance and the lesion with fluorescent excitation under blue (fluorescence) light guidance were taken by cold cup as a biopsy and also resected sequentially. To evaluate the accuracy of PDD, the levels in images of the ALA-induced fluorescence were compared with the pathological results. To evaluate the availability of TUR-Bt guided by PDD, survival Analysis regarding vesical recurrence was retrospectively examined compared to the cases underwent conventional TUR-Bt under white light guidance. Moreover, in these cases, multivariate analysis using Cox proportional-hazards model was performed to detect the clinico-pathological factor independently contribute to improving prognosis.
(Results) In the 301 specimens obtained from 57 patients, the sensitivity and specificity of PDD were 92.5% and 60.1%, whereas the sensitivity and specificity of conventional endoscopic examination under white light guidance were 81.6% and 79.5%, respectively. Median follow-up period was 19.1 (range 8.6-49.9) months in 57 patients underwent TUR-Bt guided by PDD. Eight of 57 patients recurred and recurrence-free survival rate was 88.2±0.1% (at 12 months) and 76.2±0.1% (24-48 months). Median follow-up period was 49.9 (5.0-145.0) months in 149 patients underwent conventional TUR-Bt. Ninety-nine of 149 patients recurred and recurrence-free survival rate was 60.3±0.0% (12 months) and 31.6±0.0% (24-48 months). There was statistical significance in recurrence-free survival rate between these 2 therapeutic groups (p< 0.001). Moreover, multivariate analysis revealed the independent factor contribute to improving prognosis was only TUR-Bt guided by PDD (hazard ratio 0.279, p=0.001).
(Conclusion) It was suggested that TUR-Bt guided by PDD might reduce the risk of vesical recurrence in the early stage after operation of non-muscle invasive bladder cancer.