Bladder Cancer Academy 2017: Quality Indicators and Enhanced Imaging in Cystoscope and TURBT
High quality TURBT is essential for management, being the first line treatment with diagnostic and therapeutic implications. There is a learning curve for TURBT and intravesical therapy is no substitute for poor TURBT. To perform a high quality TURBT, one must map all tumor sites prior resection, complete resection of all lesions with sampling of the muscularis propria whenever possible, and perform restaging TURBT when needed. Restaging TURBT must be done in the following scenarios: incomplete resection, presence of T1 disease, variant histology, and needs to be considered in high grade Ta disease. Importantly, detailed documentation must be available for every TURBT procedure, elaborating all stages of the procedure. The goal of high quality TURBT should be complete resection of all tumor (lesions visible with white light cystoscopy [WBC], and those only visible with other available technologic modalities). Adherence to the principle of complete resection substantially reduced recurrence rates.
Unfortunately, WLC is not a good enough modality with high residual tumor rates, reaching up to 76%. Fortunately enough, there are novel technological modalities enabling urologists to see tumor lesions not able to be seen by standard WLC. These include the Cysview, narrow band imaging (NBI), optical coherence tomography, and confocal laser endomicroscopy.
In NBI, tissues are illuminated with light of narrow bandwidth, centered on blue and green spectrum. This is strongly absorbed by Hemoglobin, thus highlighting vascular structures. Studies have shown that NBI reduces 1 year recurrence rates seen in WLC from 51% to 33% (p=0.01).1 Furthermore the rate of residual tumor decreases from 30% to 15% after NBI.2 It has also been used successfully in upper tract urothelial carcinoma with similar beneficial results.
Blue light cystoscopy (BLC) was approved in Europe in 2005 and was FDA approved in 2010. It works by installation of the Hexvix compound before TURBT. It bypasses cellular regulation mechanisms for heme synthesis and leads to 10 times greater selective accumulation of protoporphyrin IX (PpIX) in neoplastic cells due to increased mitotic rate. Under blue light illumination at 440 nm PpIX emits a red light, facilitating specific visualization of the tumor. Studies have shown an increased Ta/T1 and CIS tumor detection rate of 16%, and 32%, respectively, compared to WLC (p=0.001), and a relative reduction in recurrence of 16%.3 Additionally, a published meta-analysis including 10 prospective trials with 1345 patients demonstrated that BLC detected 14.7% and 40.8% more Ta tumors and CIS lesions, respectively, p<0.001, and had a reduced recurrence rate of 34.5% compared to 45.6% in WLC, p=0.006.4 BLC has also been shown to be cost effective with a significant lowering of cost compared to using WLC only. BLC is currently studied in the setting of a flexible cystoscope and has been shown to safely improve detection of recurrent NMIBC by 21%. Current EAU and AUA guidelines recommend using BLC for all patients with NMIBC for guidance on bladder cancer resection, in patients with positive cytology and negative WLC, aiding in CIS diagnosis, and during follow-up of patients with high risk of recurrence.
Dr. Cookson concluded his great presentation emphasizing the need to achieve a high quality TURBT and the importance of performing restaging TURBT in all appropriate settings.
Presented By: Michael Cookson, MD, MMHC, The University of Oklahoma Health Sciences Center, Oklahoma City, OK
Written By: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre
Twitter: @GoldbergHanan
References:
1. Naselli A, Introini C, Timossi L, et al. A randomized prospective trial to assess the impact of transurethral resection in narrow band imaging modality on non-muscle-invasive bladder cancer recurrence. European urology 2012; 61(5): 908-13.
2. Cauberg EC, Mamoulakis C, de la Rosette JJ, de Reijke TM. Narrow band imaging-assisted transurethral resection for non-muscle invasive bladder cancer significantly reduces residual tumour rate. World journal of urology 2011; 29(4): 503-9.
3. Stenzl A, Burger M, Fradet Y, et al. Hexaminolevulinate guided fluorescence cystoscopy reduces recurrence in patients with nonmuscle invasive bladder cancer. The Journal of urology 2010; 184(5): 1907-13.
4. Burger M, Grossman HB, Droller M, et al. Photodynamic diagnosis of non-muscle-invasive bladder cancer with hexaminolevulinate cystoscopy: a meta-analysis of detection and recurrence based on raw data. European urology 2013; 64(5): 846-54.
at the 2017 Bladder Cancer Academy - June 9 - 10 - Schaumburg, Illinois, USA