Would you compromise target coverage to meet OAR constraints for prostate radiation?

Median lobes can sometimes be challenging. There are a few options in this scenario.

First, and most simply, ensure your bladder is comfortably full for simulation. Most IMRT bladder constraints are volumetric, so larger bladder sizes make meeting constraints easier.

Second, if the median lobe is causing significant obstruction or other symptoms, you can consider a median lobe takedown procedure such as HOLEP or TURP, which may help both with symptoms and meeting constraints.

Third, consider your margins. For very large prostates, each 1 mm expansion increment from CTV yields much larger PTV volumes compared to if it was a smaller gland. If you have good image guidance and a stable setup, you can consider reducing your margins, especially ...

Generally, no, I'd treat as planned. I treat at 725 cGy/fx for 5 fx. The bladder constraints I use are D10% <18.1 Gy and D0.03cc <38.1 Gy. It's not unusual to not meet the 10% criteria in patients with large and/or irregular prostates. I have not, as yet, seen bladder damage or late effect dysfunction from doing so.

On a conceptual level, I think of the bladder as a sphere with the top of the prostate/base of the bladder being a disk pushed in on the edge of that sphere. How much actual bladder wall volume (not urine within the bladder) is added by having a large median lobe? Assuming the rest of the bladder wall stays the same and the pushed in base of the bladder disk stays the same, the only additional volume would be the lengthening of ...