Diagnosis of urothelial carcinoma of the bladder using fluorescence endoscopy

Abstract

SUMMARY Bladder cancer is a frequent disease and represents the second most common genitourinary neoplasm. Although many aspects of the management of superficial bladder cancer are now well established, significant challenges remain, which influences patient outcome. Early detection and treatment of recurrent disease is required to optimize bladder preservation, reduce patient morbidity, and increase quality of life and survival. Fluorescence endoscopy, often referred to as ‘photodynamic diagnosis’ (PDD), with intravesical application of photosensitizing agents, has been developed to enhance the early detection of bladder cancer. There is growing evidence that PDD using 5‐aminolaevulinic acid (ALA), hexyl‐ALA ester or hypericin enhances the detection of bladder cancer, particularly of high‐grade flat lesions. Furthermore, transurethral resection of bladder tumour under fluorescence guidance reduces the risk of recurrent tumours. However, the impact on the progression of disease remains unclear and must be investigated in prospective randomized trials.

Bladder Cancer in 2010: How Far have We Come?

“…30 5-aminolevulinic acid (5-ALA) is a precursor in the heme biosynthesis pathway and induces an accumulation of fluorescent endogenous porphyrins, mainly protoporphyrin IX (PPIX) in tissues of epithelial origin. 31 The exact mechanisms by which fluorescent PPIX selectively accumulates in cancerous tissue are unknown, although several theories exist, including differences in cellular metabolism, structural characteristics of diseased urothelium, inflammation, and hyperproliferation of the urothelium. 31 Several single-center studies comparing 5-ALA-fluorescent cystoscopy with conventional cystoscopy have shown an increase in recurrence-free survival, a lower residual tumor rate, and an overall improvement in the diagnosis of bladder cancer.…”

“…31 The exact mechanisms by which fluorescent PPIX selectively accumulates in cancerous tissue are unknown, although several theories exist, including differences in cellular metabolism, structural characteristics of diseased urothelium, inflammation, and hyperproliferation of the urothelium. 31 Several single-center studies comparing 5-ALA-fluorescent cystoscopy with conventional cystoscopy have shown an increase in recurrence-free survival, a lower residual tumor rate, and an overall improvement in the diagnosis of bladder cancer. 30,32 The first prospective, randomized study performed at multiple centers compared whitelight with 5-ALA-fluorescent cystoscopy and did not show a difference between groups in their recurrence-free and progression-free survival rates.…”

Kasa İnvaze Olmayan Mesane Kanserinde Hex Aminolevulinat Sistoskopisiyle Fotodinamik Tanı: Meta-Analizler Eşliğinde Değerlendirme

“…Fotodinamik tanının prensibi tümör hücreleri tarafından yüksek oranda emilen foto-duyarlaştırıcı bir ajanın mesane içine instile edilmesini takiben neoplastik hücrelerin maviviyole illüminasyon altında kırmızı floresans yayması sonucu görünürlüklerinin arttırılması temeline dayanmaktadır (10). Bu yöntem ile kırmızı florasans yayan porfirinlerin, özellikle de protoporfirin IX (PpIX)'in kanserli hücrelerde birikerek benign ve malign dokular arasındaki görsel kontrast arttırılmaktadır (10). Bu amaçla mesane kanseri tanısında kullanılan 2 ajan mevcuttur: 5-aminolevulinik asit (5-ALA) ve onun derivesi olan hexyl aminolevulinat (HAL).…”

New Approaches to Photodynamic Therapy from Types I, II and III to Type IV Using One or More Photons

“…Under operating theatre conditions PDD also provides a real-time surgical indicator on potential cancer zones which aid and guide recognition of areas in need of treatment and may even lead to an automated self-targeting detection and treatment single-shot device. Furthermore the use of photodynamic detection (PDD) following 5-ALA, hexyl-ALA or hypericin administration by transurethral resection of bladder tumours is hoped to lower cancer recurrences [131]. Others suggested to further improve the efficiency of PDD by time-resolved endoscopic detection using the measurement of fluorescence lifetimes on the subcellular level [68].…”