Anwendung der optischen Kohärenztomographie (OCT) bei der Darstellung von Urothelerkrankungen der Harnblase

PURPOSE

The technique of optical coherence tomography (OCT) has significantly improved over the last few years. This new diagnostic procedure allows imaging of tissue structure of the bladder wall during cystoscopy with high resolution.

MATERIALS AND METHODS

The penetration depth of OCT is limited to 2.5 mm. The resolution is approximately 15 microm. Fifty patients with different clinical conditions of the bladder were examined. Altogether 488 OCT images were generated.

RESULTS

OCT of normal bladder mucosa clearly shows a differentiation between urothelium, lamina propria, and smooth muscle. Cystitis and metaplasia are characterized by blurring of the laminated structure and thickening of the epithelial layer. In malignant areas there is complete loss of the regular layered tissue structure.

CONCLUSION

OCT improves the diagnosis of flat lesions of the urothelium. It has the potential for facilitating intraoperative staging of malignant areas in the bladder.

[The impact of ALA (5-aminolevulinic acid)-fluorescence detection on the prognosis of superficial bladder cancer]

PURPOSE

Throughout the past years, several studies have shown that fluorescence cystoscopy with ALA (5-aminolevulinic acid) improves the detection rate of superficial bladder tumors by approximately 20 % compared to standard white light cystoscopy. These results suggest a reduced rate of residual/recurrent tumors with the routine use of ALA fluorescence technique prior to bladder tumor resection. The present prospectively randomized study was performed to verify this hypothesis.

MATERIALS AND METHODS

A total of 115 bladder tumor patients were randomized for initial resection under white light or ALA fluorescence. After 6 to 8 weeks, a second-look resection was performed in all patients guided by ALA fluorescence. Additional white light cystoscopies were performed after 3, 6 and 12 months.

RESULTS

The second-look resection did not find a tumor in 31 of 51 (59 %) patients initially resected under white light guidance compared to 43 of 51 (84 %) patients in the fluorescence group. This difference was statistically significant (p = 0.005). At 12 months, a tumor was not found in 17 of 48 patients from the white light group vs. 25 of 47 patients from the fluorescence group (p = 0.03). Seven patients were lost to follow-up.

CONCLUSIONS

By reducing otherwise inevitable re-operations, fluorescence cystoscopy decreases morbidity and lowers treatment costs.

Excretion of matrix metalloproteinases 2 and 9 in urine is associated with a high stage and grade of bladder carcinoma

OBJECTIVES

To analyze the excretion of matrix metalloproteinases (MMPs) 2 and 9 in the urine of patients with bladder cancer according to the stage and grade of tumor and to evaluate their diagnostic clinical validity. In numerous carcinomas, increased expression of MMPs is associated with a higher grade of malignancy and poor prognosis.

METHODS

The study population included 44 controls without evidence of malignancy, 14 patients with cystitis, and 43 patients with Stage Ta-T1, 18 patients with Stage T2, and 10 patients with Stage T3-T4 bladder cancer. MMP-2 and MMP-9 excretion in urine samples was measured with gelatin zymography and related to the urine creatinine concentration. The evaluation of data was performed by univariate statistical analysis, logistic regression analysis, and receiver operating characteristic analysis.

RESULTS

The upper cutoff limit for MMP-2 and MMP-9 excretion was 277 microg/g creatinine and 648 microg/g creatinine, respectively. Levels of MMP-2 and MMP-9 correlated with each other and with tumor stage and grade. Elevated excretions were mainly observed in patients with invasive tumors (Stage T2-T4). In the receiver operating characteristic analysis, the areas under the curves for MMP-2 and MMP-9 were significantly higher in patients with muscle-invasive than in patients with noninvasive tumors. Related to the cutoff limits, the overall sensitivity to detect bladder cancer was 0.51 for MMP-2 and 0.31 for MMP-9. In logistic regression analysis, MMP-2 showed the best results.

CONCLUSIONS

Urinary excretion of MMP-2 and MMP-9 is associated with a high stage and grade of bladder cancer, and they may serve as indicators of tumor progression and recurrence in the future.

Fluorescence endoscopy with 5-aminolevulinic acid reduces early recurrence rate in superficial bladder cancer

PURPOSE

Several investigators have demonstrated an approximately 20% higher tumor detection rate by 5-aminolevulinic acid (ALA) fluorescence endoscopy compared to standard white light cystoscopy, and suggested a reduction in tumor recurrences when fluorescence endoscopy was performed as standard procedure during transurethral resection. We test this hypothesis.

MATERIALS AND METHODS

In a prospective randomized multicenter study 102 patients underwent transurethral resection of bladder tumor(s) either with white light or ALA fluorescence assisted endoscopy. A second look transurethral resection with ALA fluorescence endoscopy was performed 6 weeks after the initial operation.

RESULTS

At second look transurethral resection tumor was detected in 20 of 51 patients (39%) in the white light group and in 8 of 51 (16%) in the ALA fluorescence endoscopy group. This difference was statistically significant (p = 0.005).

CONCLUSIONS

ALA fluorescence endoscopy is an innocuous and inexpensive diagnostic procedure that significantly improves bladder tumor detection rates compared to standard white light endoscopy. In our controlled study ALA fluorescence endoscopy reduced the residual tumor detection rate at second look transurethral resection by 59%.