having your fills done under fluro just makes it easier for the doc to see where the needle is going so that he don't have to dig around looking for your port, it will not have an effect on how much he puts in, or make him be able to know what your perfect restriction will be, it will still be trial and error, just as if had it done without fluro. you will have to get fills a little at a time, regardless of whether they are done under fluro or not.
hope this helps.
All you do is go into xray and they have a real time xray so the doc can see where the needle is at in relation to your port.
good luck!!