Virtual cystoscopy: the evaluation of bladder lesions with computed tomographic virtual cystoscopy

The trophoblast cell surface antigen 2 and miR-125b axis in urothelial bladder cancer

Human trophoblast cell surface antigen 2 (Trop-2) is a 40-kDa transmembrane glycoprotein that was first identified as a marker of human trophoblast cells. Trop-2 acts on cell proliferation, adhesion, and migration by activating a number of intracellular signalling pathways. Elevated Trop-2 expression has been demonstrated in several types of cancer and correlated with aggressiveness and poor prognosis. Since no data are available on Trop-2 in bladder cancer (BC), the purpose of the study was to determine its levels in tissue specimens from normal individuals and patients with BC at different stages. Moreover, since according to recent evidence Trop-2 is a miR-125b target, miR-125b expression was also assessed in tissue specimens. Finally, the effect of the Trop-2/miR-125b axis on the proliferation and migration of BC cells was evaluated in vitro.

The Trop-2/miR-125b axis was seen to be differentially expressed in normal urothelium, non-invasive BC and invasive BC tissue. Significant miR-125b down-regulation was associated with a significant increase in Trop-2 protein levels in BC tissue and correlated with disease severity. In vitro analysis confirmed the role of miR-125b in down-modulation of Trop-2 protein levels and showed that Trop-2/miR-125b axis affects cellular proliferation in bladder tissue.

In conclusion, our findings highlight a role for the Trop-2/miR-125b axis in BC progression and suggest Trop-2 and miR-125b as diagnostic/prognostic marker candidates as well as druggable targets for innovative therapeutic approaches.

Computed tomography virtual cystoscopy for follow-up of patients with superficial bladder tumours in comparison to conventional cystoscopy: An exploratory study

Objective

To evaluate and analyse the efficacy of computed tomography (CT) virtual cystoscopy in comparison to conventional cystoscopy for the follow-up of patients with non-muscle-invasive bladder cancer.

Patients and methods

The study was done over 3 years, from April 2010 to June 2013, and included 30 patients who all had non-muscle-invasive transitional cell carcinoma (Ta, T1). The patients all underwent complete transurethral resection of the tumour and presented for first follow-up check cystoscopy. The examination was performed using a 16-slice multi-detector (MD) CT scanner. The results were compared for sensitivity and specificity in relation to the site, size, and shape of the tumour.

Results

In all, 20 lesions were detected by CT virtual cystoscopy in 18 patients, whilst the remaining 12 were lesion free. Conventional cystoscopy, detected 23 lesions in 19 patients. The sensitivity of the virtual images was 87%; its specificity in identifying lesions was 100%, with a positive predictive value of 100% and negative predictive value of 78.5%.

Conclusion

CT virtual cystoscopy is a promising technique for detecting bladder tumours and some other bladder lesions. However, the detection rate for recurrent NMIBC does not appear to be adequate to replace conventional cystoscopy.

A comparative study between full-dose and half-dose intravesical immune bacille Calmette-Guérin injection in the management of superficial bladder cancer

OBJECTIVES

To determine whether a half-dose of bacille Calmette-Guérin (BCG) can reduce toxicity without affecting its efficacy in the management of non-muscle-invasive bladder cancer.

PATIENTS AND METHODS

From January 2012 to January 2014, 80 patients with superficial bladder cancer and in the intermediate-risk group were simply randomised to receive two different doses of BCG, i.e., a full dose of 90 mg (group A) or a half-dose of 45 mg (group B). There were no significant differences in clinical and pathological characteristics between the groups. At completion of the study, 40 patients could be evaluated in each group.

RESULTS

All patients were evaluated for a follow-up of 12 months after treatment. There was no significant difference in recurrence rate (15 patients, 38%, in group A and 16, 40%, in group B) in the two groups, and no difference in progression rate of the disease, at eight patients (20%) in each group. There were significant differences between groups A and B in toxicity (grade 1 adverse events, 70% vs. 60%; grade 2, 18% vs. 7.5%, respectively). Grade 3 adverse events were only reported in group A (2.5%).

CONCLUSION

The half dose of intravesical BCG instillation can reduce the toxicity and side-effects that are associated with the treatment of superficial bladder cancer, without affecting the efficacy of therapy.

Real-time bladder lesion registration and navigation: a phantom study

Background

Bladder cancer is the fourth most common malignancy in men, with a recurrence rate of 33–64%. Tumor documentation during cystoscopy of the bladder is suboptimal and might play a role in these high recurrence rates.

Objective

In this project, a bladder registration and navigation system was developed to improve bladder tumor documentation and consequently increase reproducibility of the cystoscopy.

Materials/Methods

The bladder registration and navigation system consists of a stereo-tracker that tracks the location of a newly developed target, which is attached to the endoscope during cystoscopy. With this information the urology registration and navigation software is able to register the 3D position of a lesion of interest. Simultaneously, the endoscopic image is captured in order to combine it with this 3D position. To enable navigation, navigational cues are displayed on the monitor, which subsequently direct the cystoscopist to the previously registered lesion. To test the system, a rigid and a flexible bladder phantom was developed. The system's robustness was tested by measuring the accuracy of registering and navigating the lesions. Different calibration procedures were compared. It was also tested whether system accuracy is limited by using a previously saved calibration, to avoid surgical delay due to calibration. Urological application was tested by comparing a rotational camera (fixed to the rotating endoscope) to a non-rotational camera (dangling by gravity) used in standard urologic practice. Finally, the influence of volume differences on registering and navigating was tested.

Results/Conclusion

The bladder registration and navigation system has an acceptable accuracy for bladder lesion registration and navigation. Limitations for patient determinants included changes in bladder volume and bladder deformation. In vivo studies are required to measure the effect of these limitations and functionality in urological practice as a tool to increase reproducibility of the cystoscopy.

Emerging endoscopic and photodynamic techniques for bladder cancer detection and surveillance

This review provides an overview of emerging techniques, namely, photodynamic diagnosis (PDD), narrow band imaging (NBI), Raman spectroscopy, optical coherence tomography, virtual cystoscopy, and endoscopic microscopy for its use in the diagnosis and surveillance of bladder cancer. The technology, clinical evidence and future applications of these approaches are discussed with particular emphasis on PDD and NBI. These approaches show promise to optimise cystoscopy and transurethral resection of bladder tumours.

Multiphoton fluorescence, second harmonic generation, and fluorescence lifetime imaging of whole cleared mouse organs

Multiphoton microscopy of cleared tissue has previously been demonstrated to generate large three-dimensional (3D) volumetric image data on entire intact mouse organs using intrinsic tissue fluorescence. This technique holds great promise for performing 3D virtual biopsies, providing unique information on tissue morphology, and guidance for subsequent traditional slicing and staining. Here, we demonstrate the use of fluorescence lifetime imaging in cleared organs for achieving molecular contrast that can reveal morphologically distinct structures, even in the absence of knowledge of the underlying molecular source. In addition, we demonstrate the power of multimodal imaging, combining multiphoton fluorescence, second harmonic generation, and lifetime imaging to reveal exceptional morphological detail in an optically cleared mouse knee.