Combined use of fluorescence cystoscopy and cross-polarization OCT for diagnosis of bladder cancer and correlation with immunohistochemical markers.

The combined use of fluorescence cystoscopy and cross-polarization optical coherence tomography (CP OCT) with quantitative estimation of the OCT signal was assessed in 92 bladder zones. It demonstrated the diagnostic accuracy in detecting superficial bladder cancer of 93.6%, sensitivity 96.4%, specificity 92.1%, positive predictive value 87% and negative predictive value 97.9%. Quantitative estimation of OCT signal standard deviation in cross-polarization (CP OCT SD index) makes the visual criteria of CP OCT image assessment more objective. The level of CP OCT SD index for diagnosing superficial bladder cancer, including cancer in situ, was 4.32 dB and lower. When tumor is located on a postoperative scar, CP OCT SD index may be higher than the threshold level of 4.32 dB due to strong scattering and depolarization in scar fibrous tissue. A high inverse correlation was found between CP OCT SD index and the level expressed by p63, Ki-67, p53, CD44v6 markers.