[Virtual cystoscopy of bladder neoplasms. Preliminary experience]

Abstract

Purpose: We investigated the comparative sensitivity of virtual and conventional cystoscopy in patients with urinary bladder cancer.

Material and methods: Twelve patients (8 men and 4 women; mean age: 61 years, range: 49-73) with findings of bladder cancer at conventional cystoscopy were submitted to volumetric spiral CT of the urinary bladder. Before the examination, the urinary bladder was distended with 180-200 mL of air. CT findings were then sent to an independent workstation to generate interactive intraluminal views of the bladder. The findings of virtual cystoscopy were compared with those of conventional cystoscopy in 11 patients and with the findings of transurethral resection after urethrotomy in one patient. All lesions had pathologic confirmation.

Results: Eighteen (90%) of 20 masses detected on conventional cystoscopy were visualized with virtual cystoscopy. The latter allowed readers to identify 13 of 13 masses (100%) > 1 cm and only 5 of 7 (71%) < 1 cm; three 4-mm masses were missed. Although only a subjective evaluation of lesion size was possible on conventional cystoscopy, there seemed to be good agreement on mass size and site with both techniques.

Discussion: Cystoscopy plays a key role in the diagnosis of urinary bladder carcinoma. However cystoscopy is invasive, has a limited field of view and lacks an objective scale; moreover, it is not indicated in patients with severe urethral strictures or active vesical bleeding. In our study, virtual cystoscopy depicted all the masses > 1 cm, and a lesion in a diverticulum with a small opening. Virtual cystoscopy was also very useful in a patient with urethral stricture (who could no be submitted to conventional cystoscopy) where it showed the lesion before transurethral resection after urethrotomy. The virtual technique could also be complementary to conventional cystoscopy in evaluation of bladder base and anterior bladder neck, as well as for postchemotherapy follow-up. Unfortunately virtual cystoscopy does not allow biopsy of suspicious lesions.