In patients who have residual bladder tumors after maximal TURBT, would you boost the GTV above typical doses, 55 Gy/20 fractions or 64 Gy/32 fractions, assuming you can meet constraint?

In the British study, (55/20 + MMC), these patients were encouraged but not required to undergo complete TURBT; ~45% in each arm of the study did not get a complete TURBT. No boost was given to those who did not get a complete TURBT. 

As this is the only RCT (for some reason, the RTOG never did an RT vs CRT study), my practice is to treat all the patients the same and not boost any of them, regardless of hypo or conventional dosing.

That being said, it does not seem unreasonable to do so, if one can easily identify where the gross tumor is.