V12-01: Multimodal Enhanced Cystoscopy for Improved Bladder Tumor Resections
Conventional transurethral resection of bladder tumor (TURBT) with white light cystoscopy (WLC) has recognized shortcomings including missed small tumors, inadequate assessment of resection margins and depth, and difficulty in differentiating cancerous from benign lesions. These limitations contribute to cancer recurrences and compel the need for repeat TURBT to ensure adequate cancer staging. Adjunctive optical imaging technologies including photodynamic diagnosis (PDD), narrow band imaging (NBI), and confocal laser endomicroscopy (CLE) improve tumor identification and characterization. Given their respective strengths and complementary characteristics, we postulate that combining wide-field (PDD and NBI) with microscopic (CLE) imaging technologies will further enhance TURBT. Towards that goal, we report our preliminary experience with multimodal enhanced cystoscopy.
The study received IRB approval. PDD was performed using hexaminolevulinate (Photocure) in combination with blue light cystoscope (Storz). NBI (Olympus) was performed with an NBI-enabled camera head attached to the standard resectoscope. Probe-based CLE was performed with fluorescein as the contrast agent along with 2.6 or 0.85 mm endomicroscopes (Cellvizio, Mauna Kea Technologies). Following TURBT with PDD or NBI, the resection bed was imaged with CLE. Imaging features of the resection bed were characterized by 3 urologists and achieved consensus. _x000D_
To date, 10 subjects have undergone multimodal imaging. No adverse events were noted due to the combination of instruments or imaging agents used. Confocal imaging features of the resection bed including elastin fibers (network of thin, interwoven strands), muscle fibers (sheets of straight, connected columns) and perivesical fat (collection of dark, round globules) were observed. Muscularis propria was present in the resected tissue on pathology assessment, confirming adequate resection. Patients are currently undergoing follow-up for cancer recurrence._x000D_
We report real-time microscopic inspection of the resection bed to assess for adequate depth of resection with CLE in combination with the macroscopic imaging technologies PDD and NBI. Further studies are needed to determine if multimodal enhanced cystoscopy results in improved TURBT with adequate depth and margins of resection and decreased recurrence rate, which may eventually translate to a decreased need for repeat TURBT._x000D_