What are the current appropriate planning margins for Wilms tumor in lymph node negative cases?

How should the need for dose homogeneity be managed relative to the proximity of these target volumes to the spine? Are AREN0321(HR), 0532(VL/SR), 0533(HR), 0534(Bilat) guidelines preferred for target delineation [(kidney + preop GTV) + 1 cm to CTV + (0.5-1cm PTV)] or is the use of more recent target volume updates prescribed by AREN 1921 (CTV=GTV+0.5cm, PTV=CTV+0.5cm) & Terezakis' pediatric target volume delineation handbook acceptable for routine clinical use? How close does the PTV need to be to approximate the vertebral body when considering coverage of the adjacent vertebral bodies to ensure appropriate dose inhomogeneity? Option A: Exclude vertebral bodies to minimize size of treatment field, normal tissue exposure and thus potential late effects (2ndary malignancy, insulin resistance, etc.) Option B: Include vertebral bodies along the entire field to prevent growth asymmetry (scoliosis)