Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the stages of Childhood Astrocytomas ?
    ### Response:
    Key Points
                    - The grade of the tumor is used to plan cancer treatment.          - Low-grade astrocytomas     - High-grade astrocytomas        - An MRI is done after surgery.
                
                
                    The grade of the tumor is used to plan cancer treatment.
    