What exactly makes you think you need new rotors? Not sure what you mean by the "not cut" comment.

If you don't have any vibration on braking, they should be fine...esp with only 18K miles on them. My OEM rotors lasted about 60-70K.

I replaced mine with Brembo OEM replacements ("blanks") and I'm now at 99K and no problems, they've been great.