Improved Detection of Urothelial Carcinoma In Situ With Hexaminolevulinate Fluorescence Cystoscopy

Abstract
In this European multicenter study we compared hexaminolevulinate (HAL) fluorescence cystoscopy and standard white light cystoscopy for the detection of carcinoma in situ (CIS) in patients suspected of having high risk bladder cancer. This study was a prospective controlled, within-patient comparison of standard and HAL fluorescence cystoscopy. Eligible patients received an intravesical instillation of 50 ml HAL 8 mM solution. Cystoscopy was performed using a D light system, which provided white and blue light at 375 to 440 nm. The bladder wall was inspected and mapped, first under white light, followed by blue light. All tumors and suspicious areas identified under white light and by red fluorescence were resected or biopsied. Histological findings were assessed by an independent central pathologist blinded to the identity of the biopsies. Of 211 evaluable patients 83 (39%) had CIS, of whom 18 (22%) were detected by HAL cystoscopy only, 62 (75%) were detected by standard and HAL cystoscopy, 2 (2%) were detected by standard cystoscopy only and 1 (1%) was detected by nonguided biopsy. Therefore, HAL cystoscopy identified 28% more patients with CIS than standard cystoscopy. The side effects of HAL instillation were negligible and no unexpected events were reported. HAL fluorescence cystoscopy improves the detection of bladder CIS significantly, which has consequences for clinical management and may improve the patient prognosis. The procedure is easily implemented as an adjunct to standard cystoscopy and it adds no significant risk of complications.