The odds are that your cystoscopy will be clear, but the reason for having one every three months is that this
cancer has the nasty habit of returning and you, and your urologist, want to be sure. If he follows the usual protocol, you will be having cystoscopies every three months until two years have passed, then every six months for five years, and annually forever. It is important to keep these appointments!!
Did your urologist discuss the possibility of maintenance BCG treatments? These have been shown to significantly improve the "cure rate" for high grade bladder cancer, such as CIS.
Sara Anne