How to optimize RTdose?

Dear all users and experts,
I am trying to calculate the RTDose, but the dose in the target area is uneven and it has a long tail. How can I solve those two problem.

Chong XU

Dear @xuchong

as far as I can see you don’t have enough statistics in your simulation. Could please re-run with more primaries.

Thank you for your advise, I try it.