Welcome, Newcomer. No, you cannot use any ATX-based case with a BTX motherboard. The reason is a simple physical incompatability. If you lay your mobo flat on a surface, and look at the I/O area, notice that it is right of the center of the mobo. An ATX motherboard would have the I/O area to the left of the center of the mobo. As a result, the ATX case would have the gap for the I/O area of the mobo left of the center as well; to accomodate for installing the ATX mobo.
In short, you must use a BTX case for a BTX mobo; likewise for ATX.