5-ALA-Induced Fluorescent Cytology in the Diagnosis of Bladder Cancer—a Preliminary Report

Abstract

5-Aminolevulinic acid (ALA)-induced fluorescence cystoscopy has established itself in the detection of flat and/or small lesions. This is explained by the simple fact that there is increased uptake of ALA, altered activity of certain enzymes, and altered intracellular redistribution and storage of protoporphyrin IX (PPIX) in the malignant cells. Intracellular PPIX allows red fluorescence detection. In this preliminary study, the efficacy of 5-ALA-induced fluorescent urine cytology was compared with conventional cytology in the diagnosis of bladder tumours. In this prospective study, patients ≥18years ofage admitted to the department of urology with non-malignant conditions formed the controls and patients ≥18 years of age with imaging confirmed bladder tumours formed the study group. Freshly voided urine sample was collected from these patients and divided into two samples of 50cc each. One of these samples was sent in for conventional cytology examination, whereas the other sample was sent in for 5-ALA fluorescent photo dynamic diagnosis. Conventional cytology and 5-ALA-induced fluorescent cytology were evaluated by the same pathologist. A total of 100 patients were included in the study of which 75 patients were controls and the remaining 25 were patients with bladder tumours. The sensitivity of conventional cytology and 5-ALA-induced fluorescent cytology was 64% and 100% respectively, whereas the specificity was 96% and 98.67% respectively. The sensitivity of conventional cytology was 61.19% in low-grade cancers as compared to 75% in high-grade cancers, whereas the sensitivity was 100% with 5-ALA-induced fluorescent cytology both in low- as well as high-grade cancers. Our study shows that 5-ALA-induced fluorescent cytology is highly sensitive test to diagnose bladder cancer and shows a significant difference especially in low-grade bladder cancer when compared to conventional cytology.