ICIng on the cake.
Top Line: The proportion of patients with brain mets who are also on some form of immune checkpoint inhibition (ICI) continues to grow.
The Study: Thankfully, so does our data on outcomes with stereotactic radiosurgery (SRS) given with or around the same time as ICI. Here’s another retrospective review, this one includes 179 patients treated with SRS for brain mets at the University of Maryland, 36 of whom had “concurrent” ICI given within +/- three months from SRS. Consistent with previous reporting, local control at one year was higher with concurrent ICI (98%) than without (90%), which remained the case when looking only at the most common histology of non-small cell lung cancer (100% versus 90%, respectively). In fact, on multivariate analysis, concurrent ICI was associated with a lower risk of local failure than any other characteristic. Though radionecrosis was numerically more common with concurrent ICI (7%) than without (4%), the numbers were far too small to detect a statistical difference.
TBL: Recognizing the need to employ SRS within 3 months of immune checkpoint inhibition is pretty inevitable regardless, it’s nice to see that the synergy appears to favor benefit versus harm. | Kowalski, Radiat Oncol 2020