Do you recommend hypofractionated radiotherapy for elderly and/or poor KPS patients with diffuse IDH-mutant grade 2 glioma by extrapolation from high-grade glioma trials?

I am not aware of any trial for this specific scenario. However, hypo-fractionated radiotherapy with a higher dose per fraction and a lower total dose (for example, the Rao regimen of 15 × 2.67 Gy) is appropriate in older patients (>65–70 years of age) and in those with a poor prognosis (typically defined by a KPS of <70) afflicted by GBM (Roa et al., PMID 15051755). Using an alpha/beta ratio of 5 for a grade 2 glioma, the BED of 40 Gy in 15 fractions is 61.44, which is actually lower than the BED of 73.44 for 54 Gy in 30 fractions considered the most common dose regimen used for LGG. Therefore, I believe that it is reasonable to use 40 Gy in 15 in this case.

Because some low-grade tumors eventually progress to high-grade gliomas, even afte...