Background: The advantage of photodynamic diagnosis in detecting urothelial cell carcinoma (UCC) of the bladder has been demonstrated clearly, but it comes at the price of a higher false-positive rate. Optical coherence tomography (OCT) is a noninvasive, real-time, microstructural imaging modality that uses near-infrared light for a point analysis of the bladder-wall microstructure.
Objective: To evaluate whether adding targeted OCT analysis of lesions that are suspicious at white-light (WL) and hexaminolevulinate (HAL) fluorescence cystoscopy improves diagnostic accuracy in the detection of UCC.
Design, setting, and participants: In this prospective single-center study with same-patient comparison, patients with suspected UCC first received an intravesical instillation of HAL. Cystoscopy was performed in WL, followed by blue-light inspection and OCT scanning.
Intervention: Suspicious lesions identified by WL or HAL were evaluated by OCT and were subsequently resected or biopsied.
Measurements: We measured changes in sensitivity and specificity in detecting UCC using WL, HAL, and targeted OCT.
Results and limitations: In 66 patients studied, 232 lesions were detected, were scanned by OCT, and were subsequently resected or biopsied. Additionally, 132 areas of normal-appearing urothelium were investigated by all three methods and biopsied. On a per-lesion basis, sensitivity and specificity were respectively 69.3% and 83.7% for WL, 97.5% and 78.6% for HAL, and 97.5% and 97.9% for HAL combined with OCT. Overall, UCC was diagnosed in 58 patients (87.9%), with a per-patient sensitivity of 89.7% for WL and 100% for both HAL alone and HAL with targeted OCT. Per-patient specificity for HAL alone and targeted HAL was 62.5% and 87.5%, respectively. The limitation of OCT results from poor visualization of flat lesions in WL, making scanning a time-consuming procedure.
Conclusions: Combining fluorescence cystoscopy with targeted OCT increases the specificity of fluorescence cystoscopy significantly, with no added morbidity, and reduces the need for unnecessary (false-positive) biopsies.