Suggest Treatment For Tumor In Right Temporal Lobe

my 24 yr old son has a tumour in his right temporal lobe, about the size of a ping pong ball, based on an MRI; he is special needs, non-verbal, and has a chromosome deletion ( 13q- ); he has been having increasing headaches for 1 1/2 yrs; he is disinterested in his favourite activities; his sleep is interrupted; he is eating less; his mother died 18 yrs ago from anaplastic astrocytoma, so maybe a hereditary factor?? what is his prognosis?? - I ve heard 1 - 2 yrs but read cases where the patient was still living 10 yrs later