Does Transurethral Resection Affect the Results of Computed Tomography in the Clinical Staging of Invasive Bladder Cancer? / 대한비뇨기과학회지

ABSTRACT

Purpose: Computed tomography (CT) is commonly used for the clinical staging of bladder cancer. However, a previous transurethral resection (TUR) often results in an overestimation of a proper muscle and perivesical fat invasion in the CT. The purpose of this study was to evaluate the effects of a TUR on CT staging in patients with bladder cancer. MATERIALS AND METHODS: A total of 67 patients who underwent a radical cystectomy for primary bladder cancer were included in this study. CT was performed before a TUR in 38 patients (group 1) and after a TUR in 29 (group 2). In each patient, CT evaluated the presence or absence of a proper muscle and perivesical fat invasion and the findings were then compared with the histopathologic findings following the radical cystectomy. RESULTS: CT had an overall staging accuracy of 79.1% for a proper muscle invasion and 67.2% for a perivesical fat invasion. For a proper muscle invasion, there was a significant difference between both groups in the CT specificity (76.9% vs. 30.0%, p=0.024) while no difference in the sensitivity (92.0% vs. 89.5%) was noted. For a perivesical fat invasion, there was also a significant difference between the two groups in terms of the CT specificity (75.0% vs. 35.7%, p=0.022) while there was no difference in the sensitivity (72.2% vs. 80.0%). CONCLUSIONS: A TUR before a CT may cause a false positive result in the clinical staging of bladder cancer using CT. Therefore, to minimize the confounding effect of a TUR on CT staging, it is strongly recommended that a CT be performed before a TUR in the case of a highly suspicious invasive bladder cancer.