Confocal laser endomicroscopy is an “optical biopsy” of the bladder urothelium in that it is an en-face view, in vivo, a microscopic and minimally invasive procedure with instantaneous imaging. Cellvizio® is a unique optical biopsy system that is probe-based and used during endoscopic procedures in the gastrointestinal, pulmonary and urinary tracts.
The probe is compatible with existing endoscopes and allows real-time visualization of the tissue at the cellular level. This technology, as noted by Dr. Brausi, makes it possible to access difficult locations in the body such as the bile duct, ureters or even pancreatic cysts. As such, for urologists, it is available for cystoscopy and ureteroscopy.
Advantages of Cellvizio in the field of urology are several:
1. Allows accurate and instantaneous characterization of the bladder and upper tract suspicious areas/lesions, such as CIS or dysplasia
2. Assesses the quality of transurethral resections of the bladder through real-time characterization of lateral and deep margins
3. Provides a map and characterization of lesions during long-term surveillance of bladder cancer patients
The steps to the confocal laser endomicroscopy procedure include (i) a full cystoscopy, (ii) identification of the area of interest, (iii) instillation of fluorescein into the bladder, and subsequently (iv) confocal laser endomicroscopy of the area of interest.
Dr. Brausi notes that utilization and comfort with this technology, particularly interpreting images at the cellular level, takes some practice. As follows are several notes from his experience:
- Healthy bladder: umbrella cells (flat and large on the surface)
- Inflammatory bladder: small monomorphic cells with distinct borders with loose, infiltrative cells in the lamina propria
- Low-grade cancer: monomorphic, cohesive cells with distinct borders and papillary/well-organized architecture (increased thickness)
- High-grade cancer: pleomorphic, not cohesive cells with indistinct borders; tortuous vessels in a fibrovascular stalk
- CIS: flat, disorganized architecture; pleomorphic, not cohesive cells with indistinct borders
More recently, Dr. Brausi presented newer data assessing detection of CIS and dysplasia with confocal laser endomicroscopy among 32 patients, using bladder biopsy as a pathologic control. He noted that the concordance between imaging and pathology for CIS/dysplasia was 74%.
To conclude, Dr. Brausi noted several remarks:
- Cellvizio is an interesting, innovative technology in the diagnosis of bladder tumors
- The interpretation of images on the screen in the OR is challenging and requires time and operator experience
- The differential diagnosis between inflammation and dysplasia/CIS is difficult
- No pathologist is required in the OR
- The diagnosis of dysplasia and CIS is difficult but can be obtained in about 75% of cases
Presenter by: Maurizio Brausi, Professor and Chairman of Urology Department of Urology Ausl Modena, Carpi-Modena, Italy
Written by: Zachary Klaassen, MD, MSc – Assistant Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia, Twitter: @zklaassen_md, at the 16th Meeting of the European Section of Oncological Urology, #ESOU19, January 18-20, 2019, Prague, Czech Republic
References:
1. Brausi M, Gavioli M, De Luca G, et al. Abstract 633: Optical biopsy with confocal laser endomicroscopy (CLE): A new technology for diagnosis of bladder cancer. Preliminary results of a phase II pilot study. Eur Urol Supple 2014;13(1): Abstract 633