What prostate size, if any, is a relative contraindication for external beam RT?

I do not view the prostate size itself as a contraindication on its own to EBRT. I believe the largest prostate I have treated was ~350 cc.

The things to keep in mind when treating any prostate patient, but especially when gland sizes are large, are:

1. How well was the gland sampled? MRI can be very helpful here to make sure you have sampled the dominant lesion (even if not perfect).

2. Calculate PSA density. Patients with large prostates can easily have PSAs over 10 that is largely due to a massive benign prostate. Thus, a PSA over 10 does not necessarily mean they should be treated as intermediate risk with ADT for oncologic reasons.

3. Urinary function (AUA/IPSS). Same as with any prostate patient, if they have a high AUA/IPSS score, I ...