A Multi Center, Randomized, Parallel Controlled Study of Applying Transurethral Resection of Bladder Tumor With Adjuvant Cryoablation to Treat Bladder Cancer

Bladder tumors are one of the most commonly diagnosed urinary tumors in the world. Worldwide, it has been estimated that 429,800 new cases of and 165,100 deaths due to bladder tumor occurred in 2012. Transurethral resection (TUR) is the gold-standard treatment for non-muscle invasive bladder cancer (NMIBC). In muscle-invasive bladder cancer, TUR also plays a vital role as a bladder-sparing procedure regardless of whether it is applied as a monotherapy or in combination with chemo-radiotherapy.

Whether radical resection of a tumor is initially performed can be essential in the treatment of bladder tumors. Incomplete TUR influences a patient's prognosis, regardless of whether it is part of a NMIBC treatment or part of bladder-sparing trimodal therapy. However, the quality of TUR is one of the greatest concerns in the treatment of bladder tumor. After initial TUR, approximately 70% of patients exhibit incomplete resection re-staging TUR. Of these patients, 30% exhibit residual tumors at the resection site. To solve this problem, a second TUR 4-6 weeks after the initial TUR is recommended by the guidelines, and these repeated TURs detect residual tumors in 26-83% of cases.

The investigators sought to identify other therapies that can be combined with TUR to eliminate residual tumors. As a minimally invasive method, cryotherapy has been widely used for urological tumors, including prostate tumor and kidney tumor. With respect to bladder tumors, cryotherapy remains in the exploration phase. Only a few studies of the use of computed tomography (CT)-guided percutaneous cryoablation for the treatment of bladder cancer have been reported. Unlike solid viscera, such as the prostate or kidney, the bladder exhibits the features of hollow viscera. Cryoablation through the transurethral approach could be possible if the safety of the procedure can be ensured. Our recent animal study conducted in a porcine model demonstrated the feasibility and safety of transurethral focal, full-thickness cryoablation. No perforations were observed during two eight-minute freeze cycles. Based on the success of transurethral cryoablation in animal experiments, the investigators performed this study to explore the safety and efficacy of cryoablation as an adjuvant therapy with TUR in the treatment of bladder tumors.