Disable support for Radio Station (streams) within iTunes 7.1+. After applying this command the option ‘Radio’ will disappear in the navigation bar and the Advanced menu options.
defaults write com.apple.itunes disableRadio -bool YES
To make the command take effect, you need to restart iTunes.
Re-enable Radio stream support in iTunes with the following command:
defaults write com.apple.itunes disableRadio -bool NO