Purpose: This study was designed to assess the diagnostic accuracy and therapeutic efficacy of probe-based confocal laser endomicroscopy (pCLE), which provides real-time, in vivo histological information during transurethral resection of bladder tumors.
Methods: We performed a prospective study between August 2013 and August 2014. pCLE was performed on a total of 119 lesions in 75 patients. We analyzed the diagnostic accuracy of pCLE by comparing the confocal image reports with the pathology reports of surgical specimen. Confocal images were interpreted by a single urologist blinded to the pathology reports. The therapeutic efficacy was analyzed by comparing the outcomes in pCLE and non-pCLE groups.
Results: In a total of 119 lesions, 23 were benign and 96 were malignant. The detection accuracy for malignant lesions with pCLE was determined with a sensitivity and a positive predictive value (PPV) of 91.7% and 93.6%, respectively. For high-grade versus low-grade bladder cancer, sensitivity and PPV of pCLE were 94.5% and 89.7%, respectively. Distinguishing carcinoma in situ from inflammatory lesions also was accurate with sensitivity, specificity, and PPV of 71.4%, 81.3%, and 83.3%, respectively. The Kaplan-Meier curves revealed that the recurrence-free survival rate was significantly higher in the pCLE group than in the non-pCLE group (p = 0.031).
Conclusions: Probe-based confocal laser endomicroscopy is a promising method to provide the surgeon during the transurethral resection of a bladder tumor with real-time tumor histology, regardless of the tumor's gross appearance. Furthermore, it also may improve the therapeutic efficacy with longer recurrence-free periods.