Almost everyone has measurable results immediately. Over the course of treatments, most people lose 1 to 2 sizes. Depending on your health issues, results will take longer to achieve. But just like intense exercise, you will continue to see improvement.
If you lead a healthy lifestyle, then there is no reason you can't maintain your results. You aren't just losing inches, you are repairing your body so it can function at optimal levels. However, many people like to come back every month or two for another treatment.
Treatments should be scheduled at least one time a week, but preferrably two to three times per week for best results. This is just like exercise. It builds on each workout.