Superficial bladder cancer diagnosis — the deliberate choice between fluorescent diagnosis and optical biopsy

Abstract

Bladder carcinoma in situ (CIS) is a potentially invasive tumor whose early detection is a key step to ensuring the preservation of the bladder, reducing mortality, and improving the quality of patients’ life. The early diagnosis of bladder cancer requires a sensitive technique that can detect the lesion to determine its stage and grade. ALA induced-PpIX makes it possible to detect tumors with 90% sensitivity. ALA hexyl ester (hALA) increases the sensitivity to 95%. Macroscopic techniques require a histological biopsy to define the tumor invasiveness. Imaging with Fibered Optic Confocal Fluorescence Microscopy allows the optical sectioning of examined tissues providing images with subcellular resolution after labeling with adequate fluorescent dye chosen based on the sensitivity of the used device. Available fluorescent agents are compatible with used devices; however, their toxicity and mutagenesis studies are unsatisfactory. During imaging, an optical fiber is introduced into the bladder via the urethra and placed in contact with the bladder wall. The distinction between the different types of epithelial cells is based on the cell size, morphology, and signal intensity. Although not fully adopted for clinical application, the FOCM represents a real asset that reduces invasiveness and complements the fluorescence-based endoscopy.