I have searched and not found any mention of a hotel named Tettuccio but did find another site you might like to visit:

http://www.knowital.com/Towns/montecatini/html/welcome_monte_terme.html

also the Hotel Astoria location 100 m from the thermal complex Tettuccio - wonder if this might where you'll stay.....?

http://www.knowital.com/Towns/montecatini/html/montermastoria3.html

Hope that helps.

Cheers, Linda