What margins do you use for hypofractionated treatment of glioblastoma?

Since I am generally using hypofractionated treatment in elderly, unresectable, or poor performance status patients, I tend to favor smaller margins to minimize the risk of toxicity. The largest I would use is edema +1cm for a small tumor with minimal edema. For a large tumor with extensive edema, I...

There isn’t much data to guide us regarding which margins are appropriate in this scenario. You certainly could follow the margins used in the trials you listed. As a field, though, we are heading towards smaller CTV margins (for conventionally fractionated) GBM. So I contour T2 FLAIR changes with a...

We retreat GBMs along several lines, and the margins depend on strategy and technique.

1. Small recurrence treated with GKRS as a surrogate for resection:

a. Single session 17Gy - no margin - enhancement only - local control rate 75% retreat as needed.

b. Hypo-fractionated SRS - Gamma Knife Icon: ...