Abstract 712: Multiphoton microscopy: a potential intraoperative diagnostic tool for the detection of carcinoma in situ in human bladder.

Abstract

Abstract Context: Urothelial carcinoma in situ (CIS) is a precursor of invasive bladder cancer, which if left untreated, is very likely to progress. White light cystoscopy (WLC) along with transurethral resection (TURB) is standard of care in diagnosis and treatment of these tumors. However, approximately 50% of CIS lesions are missed on WLC due to their flat architecture. Moreover, the magnifications of current cystoscopes do not provide high enough (i.e., cellular) resolution to distinguish CIS from other benign flat lesions. This results in unnecessary benign biopsies, with associated complications and cost. Multiphoton microscopy (MPM) is a nonlinear optical imaging technique capable of generating real-time subcellular-resolution images solely from intrinsic tissue signals (autofluorescence and scattering). Objective: While miniaturization of MPM for in vivo use is in progress, here we assess its diagnostic potential using a bench-top system and fresh (unprocessed and unstained) biopsies. Specifically, we assess the ability of MPM to identify CIS and to differentiate CIS from other benign flat lesions. Design: Fifty-one bladder biopsies were obtained from flat lesions via TURB / cold cup procedures (22 CIS and 29 benign, as diagnosed on histopathology). Immediately after excision, they were imaged fresh with MPM and then submitted in formalin for routine hematoxylin/eosin (H&E)-stained histopathology. A preliminary blinded study was conducted by a single study pathologist, where diagnoses were first made on the MPM images alone, and subsequently compared with gold standard H&E diagnoses. A more comprehensive blinded study with a larger sample size and two additional uropathologists is underway. Results: Flat (non-papillary) architecture was evident for all cases on low magnification MPM images. In 44/51 cases (86.3%), accurate MPM diagnosis (benign or CIS) were given based on their cytological features (nuclear-cytoplasmic ratio, pleomorphism etc).The sensitivity and specificity of MPM in this preliminary analysis were 77.3% and 93.1%, respectively. A positive (neoplastic) diagnosis on MPM had a high predictive value (89.5%), and negative (benign) diagnoses had a predictive value of 84.4%. Conclusion: Our study demonstrates the capability of MPM in not only identifying CIS lesions but also in differentiating them from other benign flat lesions of bladder. We thus foresee real-time applications of the miniaturized instrument during cystoscopy in guiding the surgeon to resect only CIS lesions, leaving behind other benign flat lesions. This will reduce the rate of benign biopsies and their associated complications (bleeding, infection and occasionally bladder perforation). We thus posit that MPM can prove to be a potential in-vivo diagnostic tool that can improve patient prognosis. Citation Format: Manu Jain, Brian D. Robinson, Maria M. Shevchuk, Amit Aggarwal, Bekheit Salamoon, Vishal Chandel, Joshua Sterling, Douglas S. Scherr, Sushmita Mukherjee. Multiphoton microscopy: a potential intraoperative diagnostic tool for the detection of carcinoma in situ in human bladder. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 712. doi:10.1158/1538-7445.AM2013-712