Rendering$Cache$ increases

Hello, because I need to save disk space, I came across the folder “Rendering$Chache$” (~/Library/Application Support/McNeel/Rhinoceros/8.0), which is several GB in size, while searching for large files. The files there are about 350 mb each and some of them are almost a year old.
I would like to know: what is this about? Shouldn’t such a cache delete itself at some point and free up storage space? Or is it advisable to dive into the system from time to time and look there and delete the cache manually? Many thanks for any advice!