Size of bladder cancers: correlation among different types of measurement.

OBJECTIVE: It was the aim of this study to evaluate the accuracy of the measurement of tumor size comparing the objective size with that measured by preoperative cystoscopy, by preoperative ultrasound (US) and with the diameter described by the operator before the transurethral resection. PATIENTS AND METHODS: This study included 100 patients with bladder papillary endoscopic features of single or multiple neoplasms who were candidates for transurethral resection. The sizes of the same neoplasms measured during preoperative cystoscopy, preoperative US and described by the operator before the transurethral resection were evaluated. A statistical analysis of the errors of measurement was performed if compared with an objective measurement done with an ureteral catheter. RESULTS: The statistical analysis of the data shows that there are no substantial differences between the objective and subjective measurement, and therefore, the measurements reported by individual operators are reliable. On the contrary, the diameters given by preoperative cystoscopy and US differ significantly from the objective measurement. CONCLUSIONS: This study shows that the most reliable measurement is the subjective measurement made directly by the urologist in the operating room.