Not really. A round trip transatlantic flight hits you with ~0.06 to 0.1 mSv and a chest x-ray is on the order of up to ~0.02 to 0.1 mSv, so roughly similar. There's a reason x-ray techs stand behind a wall, you have a VERY small chance of DNA damage with each exposure and for most people that doesn't matter because you don't fly that often or get that many x-rays but if you do it all the time, your bound to have a high energy particle smash into the wrong part of a cell's DNA. This isn't an effect of cumulative small doses but rather rolling the same dice many times.