Investigation on the Usefulness of Photodynamic Diagnosis-assisted Targeted Bladder Biopsy: Japanese Real-world Study

Abstract

Background/aim: Photodynamic diagnosis (PDD)-assisted transurethral resection of a bladder tumor (PDD-TURBT) in a patient receiving 5-aminolevulinic acid improved the detection of micro- and flat lesions of the bladder. This study used real-world data in Japan to examine the diagnostic accuracy of PDD-assisted targeted biopsies and white-light (WL) random biopsies and reevaluated the necessity of random biopsies.

Patients and methods: A total of 133 patients diagnosed with bladder cancer who underwent TURBT from April 2020 to March 2022 were included in the study. Biopsy specimens obtained from 407 flat lesions or normal-like lesions, excluding biopsies from elevated lesions and TUR specimens, were used to analyze diagnostic accuracy in PDD and WL findings.

Results: The respective sensitivities, specificities, and negative predictive values of PDD vs. WL findings were 81.4% vs. 54.0% (p=0.0039), 70.4% vs. 81.4% (p=0.0012), and 96.4% vs. 90.6% (p=0.0144), indicating that PDD was useful for a diagnosis of exclusion. Combining the PDD and WL findings improved the detection of malignant flat lesions. Ten (PDD-positive and WL-negative) specimens from 9 patients were diagnosed as malignant. The results of PDD-assisted targeted biopsy provided an accurate assessment of the risk classification for recurrence and progression of non-muscle invasive bladder cancer (NMIBC) as defined by the Japanese Urological Association (JUA) guidelines.

Conclusion: For NMIBC treatment, a more accurate diagnosis is important for postoperative treatment decisions. PDD-assisted targeted biopsy may be necessary and sufficient for diagnosis of flat lesions in patients with bladder cancer for treatment decision making based on JUA risk classification.

Keywords: Bladder cancer; NMIBC; PDD-TURBT; PDD-assisted targeted biopsy; photodynamic diagnosis; transurethral resection of bladder tumor.