How would you approach radiotherapy planning for a pediatric patient with Ewing sarcoma of the spine (vertebral body primary)?

Per the recent AEWS 1031 protocol:

GTV1 is defined as the visible and/or palpable disease defined by physical examination, CT, MRI, and/or PET prior to any surgical debulking or chemotherapy.

GTV2 is defined as a residual visible or palpable tumor as assessed by CT, MRI, PET, or physical exam after ...