It might work on the esophagus. What's happening here is FDA is approving it for liver only. Perhaps that changes in the future.
Can you get the procedure without FDA approval?
Well, plenty of drugs are prescribed "off script". That is the medication is supposed to be prescribed for Ailment X but it's known to work for Z, and is used for patients with Z.
Are physical procedures the same? IDK. But of course, there might also be other countries that have the equipment and are willing to use it more broadly.