ORLANDO, FL (UroToday.com) - Has BCG worked? In order to allow the urothelium to recover from the immunotherapy insult, the urologist often has to wait several weeks before the patient can be evaluated cystoscopically and cytology can be obtained. Whitson et al. demonstrate that FISH performed on a voided urine sample 1 week after BCG therapy had sensitivity that was similar to cystoscopy+cytology performed at 6-weeks following the intravesical therapy cycle.