This is such a hard question to answer.
The two current options you have for clinical trials are both located in the US. There is the DFMO trial and the vaccine trial
Both are pretty costly and involve international travel and significant expenses.
Short of those options the standard recommendation from COG and SIOPEN is just to wait and see.
The vaccine trial has 2 weeks on and 2 weeks off of beta glucan for 11 months, this stimulates the immune system and supposedly increases the effect of the vaccine. One pretty low risk possibility could be taking beta glucan at the same dosage that Sloan provide, since its a drug that is very readily available. There are some papers out there that talk about the effect. But yeah, you would have to consult your Oncologist on that.