Impact of photodynamic diagnosis-assisted transurethral resection of bladder tumors on the prognostic outcome after radical cystectomy: results from PROMETRICS 2011

Role of Macroscopic Image Enhancement in Diagnosis of Non-Muscle-Invasive Bladder Cancer: An Analytical Review

Early diagnosis of non-muscle-invasive bladder cancer (NMIBC) is of paramount importance to prevent morbidity and mortality due to bladder cancer. Although white light imaging (WLI) cystoscopy has long been considered the gold standard in the diagnosis of bladder cancer, it can miss lesions in a substantial percentage of patients and is very likely to miss carcinoma in situ and dysplasia. Tumor margin detection by WLI can be inaccurate. Moreover, WLI could, sometimes, be inadequate in distinguishing inflammation and malignancy. To improve the diagnostic efficacy of cystoscopy, various optical image enhancement modalities have been studied. These image enhancement modalities have been classified as macroscopic, microscopic, or molecular. Photodynamic diagnosis (PDD), narrow band imaging (NBI), and Storz image 1 S enhancement (formerly known as SPIES) are macroscopic image enhancement modalities. A relevant search was performed for literature describing macroscopic image enhancement modalities like PDD, NBI, and image 1 S enhancement. The advantages, limitations, and usefulness of each of these in the diagnosis of bladder cancer were studied. Photodynamic diagnosis requires intravesical instillation of a photosensitizing agent and a special blue light cystoscope system. PDD has been shown to be more sensitive than WLI in the detection of bladder cancer. It is superior to WLI in the detection of flat lesions. Bladder tumor resection (TURBT) by PDD results in more complete resection and reduced recurrence rates. PDD-guided TURBT may have some role in reducing the risk of progression. Narrow band imaging provides increased contrast between normal and abnormal tissues based on neovascularization, thereby augmenting WLI. NBI requires a special light source. There is no need for intravesical contrast instillation. NBI is superior to WLI in the detection of bladder cancer. The addition of NBI to WLI improves the detection of flat lesions like carcinoma in situ. NBI is not useful in predicting invasive tumors or grades of tumors. NBI-directed TURBT reduces recurrence rates and recurrence free survival. But its efficacy in retarding progression is unproven. Image 1 S-enhancement utilizes software-based image enhancement modes without the need for a special light source or intravesical contrast instillation. This system provides high-quality images and identifies additional abnormal-looking areas. Another advantage of this system is simultaneous side-by-side visualization of WLI and enhanced image, providing WLI images as the control for comparison. As with PDD, S-enhancement produces a lower rate of a missed bladder cancer diagnosis. The system significantly improves the diagnosis of NMIBC. The sensitivity and negative predictive value of image 1 S enhancement increase with the increase in cancer grade. A negative test by S-enhancement effectively rules out NMIBC. All the image enhancement modalities have proven their utility in improving detection and short-term cancer control. But none of these modalities have proven their utility in delaying progression, or in long-term cancer control. Cancer progression and long-term control are governed by the biological nature of cancer cells. Early detection by optical enhancement may not be of utility in this regard. Well-designed studies are needed to establish the efficacy of these modalities in the evaluation of patients with bladder cancer. The last word, in this regard, is yet to be written.

[Supplementary optical techniques for the detection of nonmuscle invasive bladder cancer]

White light cystoscopy (WL) is the gold standard for the detection of bladder cancer. It can be performed using a rigid or flexible urethrocystoscope. With the more recent introduction of high definition (HD) techniques, WL cystoscopy has been decisively improved. Supplementary optical techniques are also used to improve the detection of bladder cancer. Among these are photodynamic diagnosis (PDD), narrow-band imaging (NBI), S‑technologies of IMAGE1 S, optical coherence tomography (OCT), confocal laser endomicroscopy (CLE), and Raman spectroscopy. The aim of the present work is to introduce the techniques and to discuss their current role and future potential in the detection of bladder cancer.

Novel endoscopic visualization techniques for bladder cancer detection: a review of the contemporary literature

PURPOSE OF REVIEW

To describe the principles of photodynamic diagnosis (PDD), narrow-band imaging (NBI) and Storz Professional Image Enhancement System (SPIES) techniques for the endoscopic management of nonmuscle-invasive bladder cancer (BCa) and to report their impact on clinical practice.

RECENT FINDINGS

PDD is associated with an increased sensitivity for detecting BCa specifically carcinoma in situ (CIS). Moreover, PDD has been shown to lower recurrence rate in comparison with white-light cystoscopy. The impact on progression-free survival is still unclear yet. NBI and, more recently, SPIES are two novel imaging techniques that do not require preoperative instillation of photosensitizing agents. NBI seems to be associated with lower recurrence rates. Nevertheless, further trials are necessary to confirm these results, in particular in high-risk lesions and CIS. Randomized clinical trials addressing the clinical impact of SPIES are ongoing.

SUMMARY

Novel endoscopic imaging techniques are useful diagnostic tools for evaluating BCa during cystoscopic diagnostic surveillance as well as during transurethral resection of the bladder. Although the standard of care remains white-light cystoscopy, these techniques provide higher sensitivity in detecting BCa especially CIS. The continued evidence also suggests that this increased detection leads to lower recurrence rates. The impact on progression and the cost-efficacy as well as selection remains to be refined.

Current concept of transurethral resection of bladder cancer: from re-transurethral resection of bladder cancer to en-bloc resection

PURPOSE OF REVIEW

Transurethral resection of bladder cancer (TURB) is the critical step in the management of nonmuscle invasive bladder cancer (NMIBC). This review presents new improvements in the strategy and technique of TURB as well as in technological developments used for tumour visualization and removal.

RECENT FINDINGS

The goal of TURB is to perform complete resection of NMIBC. Tumor visualization during procedure can be improved by enhanced optical technologies. Fluorescence-guided photodynamic diagnosis (PDD) and narrow-band imaging (NBI) used during TURB can improve tumour detection and potentially reduce recurrence rate, their influence on progression, however, remains controversial. TURB can be performed using monopolar or bipolar electrocautery without significant differences in results or safety. To overcome limitations of traditional TURB, the technique of en-bloc resection was introduced to improve the quality of tumour removal. In selected cases, an early re-resection (re-TURB) within 2-6 weeks after initial procedure is recommended.

SUMMARY

TURB is a fundamental step in diagnosis and treatment of NMIBC. Urologists should be aware of promising innovations including new imaging and surgical techniques and their potential benefits. Hopefully, new technologies and performance of TURB bring improved outcomes, which can alter the indication criteria for re-TURB.