I usually don't ask the medical oncologist to wait to deliver chemotherapy after SRS for brain mets.  When delivering whole brain radiotherapy, there is some breakdown of the "blood-brain barrier" and this may account for the increased toxicity we see when chemotherapy is delivered during whole...

I agree with the answer by @Shripal K. Bhavsar since I also do not ask the medical oncologist to wait any period of time following SRS. In lung cancer, it isn't uncommon to have oligoprogression in the brain while a patient is on systemic therapy that is going to be continued. Often I am sandwi...

I agree with the answers above that it should be safe in most cases to give systemic therapy immediately after and even concurrently with SRS. Our institutional experience showed minimal toxicity with SRS given concurrently with both conventional chemotherapy and newer targeted systemic therapies, a...

There is no magic number. I think immunotherapies will probably demonstrate a more brisk responce. Interestingly, I think we often see less of a reaction when chemo is added after SRS. My guess is this occurs because some necrosis isn't directly related to RT damage but rather cytoxic effect of tumo...

Only caveat will be giving immunotherapy concurrently with brain SRS which has shown increased toxicity.