Confocal laser endomicroscopy

Confocal laser endomicroscopy (CLE) is a promising fluorescence-based fiber-optic imaging technique able to provide a microscopical assessment of tissues. It was developed in 2007 and was first used to study histopathologic changes in bronchial and enteric tissue (Thiberville et al., Am J Respir Crit Care Med 175(1):22-31, 2007; Wang et al., Clin Gastroenterolo Hepatol 5:1300-5, 2007). In 2009 it was proposed that CLE could be used for real-time visualization of tissue microarchitecture and cellular morphology of the lower urinary tract, with improved diagnosis of urothelial carcinoma (Sonn et al., J Urol 182:1299-305, 2009) (i.e., tumor grading) and, more recently, CLE has been used in the upper urinary tract with similar purposes (Villa et al., J Endourol 30(2):237-42, 2016; Breda et al., Eur Urol Focus 4(6):954-959, 2018). Similarly, reflectance confocal microscopy has been introduced in 2007 in the field of dermatology to improve the diagnostic specificity when integrated with dermoscopy (Pellacani et al., J Invest Dermatol 127(12):2759-5, 2007; Guitera et al., J Invest Dermatol 132(10):2386-2394, 2012). As far as prostate cancer is concerned, it has been used more recently to microscopically depict prostate tissue, distinguishing between cancerous and non-cancerous one; the real-time fashion of CLE makes it suitable for the intra-operative setting, to assess surgical margin status thus tailoring the correct plane of dissection (Puliatti et al., BJU Int 124(3):469-476, 2019; Lopez et al., J Urol 195(4 Pt 1):1110-1117, 2016)