Storz Professional Image Enhancement System (SPIES) Versus Conventional White Light Imaging (WLI) Assisted Transurethral Resection of Bladder Tumour (TURBT) for Treatment of Non-muscle Invasive Bladder Cancer (NMIBC)

Urothelial carcinoma of the bladder is the 2nd most common urological malignancy. The vast majority of newly diagnosed cases are non-muscle invasive bladder cancers (NMIBC), which represent about 75%, and it can be treated with transurethral resection (TURBT). The goal of TURBT in Ta and T1 NMIBC is to make the correct diagnosis and completely remove all visible lesions. The quality of TURBT strongly determines patient prognosis and overall treatment.

White light cystoscopy (WLC) remains despite of its limitations the cornerstone of the diagnosis and subsequent treatment of NMIBC. The sensitivity and specificity of WLC range from 62% to 84% and 43% to 98%, respectively. Its sensitivity is lower for small papillary bladder tumors and carcinoma in situ (CIS). Moreover, the accuracy of WLC has been shown to be operator dependent.

Smaller or satellite tumors can be missed, which contributes to almost 40% rate of residual bladder cancer found at the time of 'second-look' TUR. Indistinct borders and difficult visualization of submucosal tumor margins during TUR can lead to incomplete tumor resection and understaging of bladder cancer and leads to tumor recurrence which range from 15% to 61% at one year after surgery based on combined analysis of seven EORTC studies. 3 Non-papillary and flat malignant lesions such as carcinoma in situ (CIS) can be difficult to differentiate from inflammation, with detection rates of CIS only 58% to 68% by WLC.

Fluorescence cystoscopy also known as blue light cystoscopy or photodynamic diagnosis (PDD) requires preoperative intravesical administration of protoporphyrin IX precursor as the contrast agent, a blue light source that illuminates at 375 to 440 nm. Protoporphyrin accumulates preferentially in neoplastic cells and emits fluorescence in the red part of the spectrum under blue light excitation. Though PDD also does not distinguish high-grade from low-grade bladder cancer, PDD has an increased rate of detection of flat appearing CIS vs WLC (87% vs 75% pooled sensitivity; P= .006).

The recurrence rate of PDD-guided TUR of bladder tumor is a matter of controversy. In a meta-analysis of prospective studies on 1345 patients with overall 12 months recurrence rate was significantly lower with PDD compared with WLC (34.5% vs 45.4% pooled sensitivity; P=0.006). However, a prospective randomized multi-institutional trial found no difference in tumor recurrence and progression between PDD and WLC.