Yes, you can, but you will sound like Shakespeare!

I agree with fdmaxey - you're likely to cause confusion if you simply replace "outside" with "without". You may be understood more clearly if you use its opposite "within" in the same text, but it's still tricky.

While "without" can mean "outside" it is almost never used that way today. You would be correct in saying "My brother is waiting without" - meaning "My brother is waiting outside". Today, though, a lot of native English speakers might ask "Without what - shoes?". You would simply have more chance of being understood if you used "outside".