When treating resected brain metastases with post-op SRS, what dose, fractionation and PTV margin do you use for large (>3 cm) cavities?

I would refer you to Scott Soltys' work:

Choi et al., PMID 22652105

Soltys et al., PMID 17881139

This is also useful:

Brennan et al., PMID 24331659

I think it's a reasonable approach (fractionation). It is certainly one we use at our institution. Having said that, this is only based on retrospective reports. It will be interesting to see the manuscripts of the MDACC and Alliance trials as the reported local control rates were lower than expecte...

In fact, I rarely use true postoperative SRS. A lower fractional dose enables using larger CTV margins safely if there is concern for potential residual microscopic disease and risk for leptomeningeal disease (LMD). CTV margin also depends on how linear the surgical bed surface is. The entirety of t...