What dose and volumes do you use for incompletely resected WHO grade II meningiomas with brain invasion?

Several articles report results with 0.5 -1 cm margins, and have suggested that with improved imaging and treatment planning, smaller margins such as those used by the EORTC are also appropriate for GTV to CTV expansion. The 2 cm expansions used in RTOG 0539 may result in much larger volumes of normal brain exposed to radiation. Is it therefore reasonable to treat patients with larger Simpson Grade 4, subtotally resected Grade II meningioma, with a 1 cm GTV to CTV expansion? Articles: Combs et al., PMID 33309848 Press et al., PMID 24661652 Rogers et al., PMID 31786276 Weber et al., PMID 29960684