Phase II multi-center trial of optical coherence tomography as an adjunct to white light cystoscopy for intravesical real time imaging and staging of bladder cancer.

ABSTRACT

BACKGROUND: Optical coherence tomography (OCT) is a novel imaging modality that provides microstructural information of different tissue layers using near-infrared light. This prospective, multicenter phase II trial aimed to assess the accuracy of OCT-assisted cystoscopy for bladder tumor staging. METHODS: Patients with primary or recurrent bladder tumors (Ta,T1) identified by outpatient cystoscopy were included. The primary objective was to assess the accuracy and positive predictive value of for determining tumor stage ≥T1 correlated by histopathology. 72 suspicious lesions from 63 patients were eligible to analyze in the study. All suspected lesions were evaluated with conventional cystoscopy, interpreted in real-time using OCT, and then resected. All results were compared to pathology. A total of 363 OCT images of tumor and normal mucosa in 25 patients were obtained to evaluate diagnostic efficacy of the computer-aided texture analysis algorithm. RESULTS: Sensitivity and specificity for predicting invasive tumors (≥ T1, n = 17) were 58.8% and 92.7% for cystoscopy, 64.7% and 100% for OCT-assisted cystoscopy, respectively. Accuracy of cystoscopy and OCT-assisted cystoscopy for predicting invasive tumor was 84.7% and 91.7% (P = 0.063), respectively. Cystoscopy and OCT-assisted cystoscopy correctly predicted T stage in 52/72 and 59/72 cases, respectively (P = 0.016). Cystoscopy missed 2 more invasive tumors than OCT-assisted cystoscopy. Cystoscopy (14.3%, 1/7) and OCT-assisted cystoscopy (28.6%, 2/7) showed relatively low sensitivity in detecting muscle invasion. Computer aided texture analysis demonstrated 75.1% sensitivity, 64.0% specificity, and 74.4% accuracy for differentiating tumor and normal urothelium. CONCLUSION: OCT-assisted cystoscopy is a real time noninvasive and simple procedure that enhanced the accuracy of staging bladder tumors and prediction of any tumor invasion. Though the study did not meet the prespecified primary endpoint, OCT imaging is a promising adjunct to cystoscopy that may supplement intraoperative decision-making during transurethral resection of bladder tumors and additional prospective studies are warranted.