Grading upper tract urothelial carcinoma with the attenuation coefficient of in-vivo optical coherence tomography.

INTRODUCTION

With catheter based optical coherence tomography (OCT), high resolution images of the upper urinary tract can be obtained, thereby facilitating the detection of upper tract urothelial carcinomas (UTUC). We hypothesized that the attenuation coefficient of the OCT signal (μ ) is related to the histopathologic grade of the tumor.

OBJECTIVES

In this study, we aimed to define the μ cut-off for discriminating high grade and low grade papillary UTUC.

METHODS

For this post-hoc analysis, data from OCT imaging of papillary UTUC was obtained from patients during ureterorenoscopy. OCT images and raw data were simultaneously analyzed with in-house developed software. The μ determined in papillary UTUCs and corresponding histopathologic grading from either biopsies or radical resection specimens were compared.

RESULTS

Thirty-five papillary UTUC from 35 patients were included. μ analysis was feasible in all cases. The median μ was 3.3 mm (IQR 2.7-3.7 mm ) for low-grade UTUC and 4.9 mm (IQR 4.3-6.1 mm ) for high-grade UTUC (P = 0.004). ROC analysis yielded a μ cut-off value of >4.0 mm (AUC = 0.85, P < 0.001) with a sensitivity of 83% and a specificity of 94% for high-grade papillary UTUC.

CONCLUSIONS

This study proposes a μ cut-off of 4.0 mm for quantitative grading of UTUC with ureterorenoscopic OCT imaging. The promising diagnostic accuracy calculations justify further studies to validate the proposed cut-off value. Implementation of the software for the μ analysis in OCT systems may allow for μ assessment at real time during ureterorenoscopy. Lasers Surg. Med. 51:399-406, 2019. © 2019 Wiley Periodicals, Inc.