V12-02: Confocal Laser Endomicroscopy for bladder cancer diagnosis: how to do it & our preliminary results
Cystoscopy is the cornerstone in bladder cancer diagnosis and monitoring. Although very effective, conventional white light cystoscopy has its limitations. New techniques have been developed to improve visualisation of tumours and suspicious lesions. However, no information can be given on grade of the disease during cystoscopy or per-operatively as no histopathologic information can be obtained real time. Confocal Laser Endomicroscopy (CLE) is a unique new imaging technique. It allows in vivo optical sectioning of tissue and provides real time microscopic images with high resolution. The objective of this study is to assess if we can take &[prime]optical biopsies&[prime] of the bladder using CLE.
We performed CLE in 19 patients with a bladder tumour, during transurethral resection of the bladder tumour (TURB). At the beginning of the procedure, after initial evaluation of the bladder, 360 ml of 0.1% Fluorescein, a fluorescent contrast agent, was administered intravesical via an indwelling catheter. After 5 minutes CLE was performed using the Cystoflex UHD R (Cellvizio, Mauna Kea, Paris, France), which has a resolution of 1 μm, a field of view of 240 μm, and an imaging depth of 50-65 μm. The CLE probe was introduced via the working channel of the cystoscope (Olympus or Storz 0 - 12°). CLE images were obtained of healthy tissue and tumours, and correlated with histopathology and analysed afterwards. After obtaining CLE images, the tumour was resected en-bloc. Tumour grade was assessed according to the WHO 2004 classification.
We were able to obtain good CLE images when the probe was correctly positioned. The probe has to be in good contact with the tissue, and perpendicular to the surface. Of the 19 patients; 2 had a benign lesion, 12 low-grade urothelial carcinoma, and 5 high-grade carcinoma. Differences in CLE images could be seen between healthy tissue and tumour (figure 1).
During TURB it was possible to take &[prime]optical biopsies&[prime] of the bladder. The obtained CLE images could give real time histopathologic information, and has the potential to differentiate in tumour grade during cystoscopy. These &[prime]optical biopsies&[prime] may assist urologist in future clinical practice in bladder cancer diagnosis and follow-up.
Funding: This study was supported by the Cure for Cancer foundation (http://www.cureforcancer.nl).