Lynne, There are no spas in Prague. Podebrady Spa is NEAR Prague. For a look at some of the spas in the Czech Republic see: www.travel.cz/spatown.asp Houby
The above address has changed. Use: www.travel.cz/travel/spatowns.php3 Or make a Google Search "Czech Spas" Houby
I see CSA (USA 1-877-293-4225) is advertising a Spa in Prague. It appears to be a "Beauty Spa" and not the traditional "Medical Spa". This maybe what you're looking for.