Question about brain radiation

Your radiation oncologist is going to be your source for this info.   He/she will be keeping track of accumulated dose to various areas of your brain.

If they have been treating the same lesions in the same locations more than once, the answer will be different than if they are treating different lesions in different locations.   SRS structures the radiation exposure so it converges in the tumor, and the surrounding tissues get a lower exposure.   

I was a Radiation Safety Officer at a University for 25 years, though we didn't treat people with radiation.   My wife had two tumors in her brain treated with Gamma Knife in August 2017, and I spent the entire treatment talking to the Health Physicist at the gamma knife facility.   Because of my background, he was very informative and went over what they do in detail.

Your rad onc is definitely the one with the best advice and most info to give you. I'm sure it depends more on the total tumor volume that you've had treated. From a more personal perspective… I've had 10 rounds of gamma knife. Yup… 10 times on 10 separate dates between April 2013 and Feb 2016. 2014 was a horrible year for me, with 7 in one year. I've had a total of 39 lesions zapped…. most caught very early with frequent brain MRI's. Soooooo… apparently, you can dip into that well plenty regularly, and still come out with less overall radiation exposure than you'd have gotten with whole brain. Nooooot that you want to keep having to rely on another brain frying to buy time for something else to kick in… but don't worry yourself just yet. 🙂