Can I do this legally without getting sued at court? I need help!!!?

Okay, here's my problem. Call me a dreamer if you will, but I'm writing a superhero novel that I hope to get published in the near future. It's set in modern-day England and the superhero's title (just as there's Spider-Man, Bat-Man, Super-Man, etc) is Mega-Man. This I made up (or thought I did) as an abbreviation for Man of the Megalith (the stonehenge in Salisbury Plain) which would be too long to say. Thus, they call him Mega-Man. Also, it just sounds a lot cooler, bad-a**, and all-around-Superhero. Sadly, however, I found out that Mega-Man is a part of a computer game with several sequels. In light of this, would I be able to use it for a title of my series or not? It's imperative to the plot outline that means I'll have to make changes to it should I be unable to use Mega-Man for the title. Thanks a ton in advance. I'm eagerly looking forward to whatever you have to say!! :-)