Medulloblastoma - stronger medication

Our grandson has braincancer medulloblastoma. He is about 17 months post rad and chemo. Last week he was back in Rome to have his nomal scan. 

My wife is worried because the parents won't divulge why the doctor recommended stronger medication. I have a feeling the cancer returned. Is there

anyother reason why the doctor would prescribe a stronger medication?? Our granson has never fully recovered the ability to walk. Not for a period of time on his own.

We might be making an unexpected trip to Italy and all we can do is pray for the best. 

thx