Looking for information on ESDT

My 32-year-old son has a benign esophageal stricture. He has been going to the hospital for dilation every 2 weeks for the last 6 months. If he goes beyond the 2 week period, he has difficulty swallowing again. He's interested in esophageal self dilation therapy (ESDT). We are in the Cookville, Tennessee region. Where are the closest courses?