What are the chances of a brain tumor anaplastic astrocytoma gr 3 reaccuring in a child if the tumor was removed?

High. Unfortunately pediatric anaplastic astrocytoma (grade 3 glioma) has high recurrence rates. Degree of resection does impact prognosis. However, those with grade 3 astrocytoma tend to have pfs (progression free survival) of 40 to 50% even with adjuvant chemotherapy and radiation.
Moderately high. It can be 50%...What you want is the best adjuvant therapy: radiation and chemotherapy. I am a believer in using protons in children to avoid as much normal tissue as possible - I have access to both regular x-rays (imrt/vmat) and protons and the latter are far superior in almost all cases. Gamma knife is not something I use for gliomas like this for a number of important reasons.