Trimodality treatment for bladder cancer: does modern radiotherapy improve the end results?

ABSTRACT

With the advancement in endoscopic surgery, radiation treatment planning and execution, as well as the use of new chemotherapeutic regimens, bladder conservation has evolved into a competing alternative to radical cystectomy. Trimodality treatment has the great advantage of preserving a normally functioning urinary bladder. Despite the absence of direct randomized trials comparing both modalities, trimodality treatment comprising maximal transuretheral resection of bladder tumors followed by different regimens of combined radiochemotherapy achieved comparable results to radical cystectomy in many trials. Those who did not achieve complete remission after induction radiochemotherapy were salvaged by radical cystectomy. Improving the radiotherapeutic window is a challenging issue. In radiotherapy for bladder cancer, uncertainties include set-up errors, patient movement, internal organ movement and volume changes due to bladder filling (both inter- and intrafraction). The advancement in treatment verification procedures in modern radiotherapy and the use of fiducial markers reduces set-up errors, while adaptive radiotherapy could decrease the unnecessary irradiation of normal tissues by tracking bladder volume changes. In addition, new radiotherapeutic techniques, such as intensity-modulated radiotherapy and volume-modulated radiotherapy, permit dose escalation to the target without increasing the dose to the surrounding normal tissues.