Check for table existence before dropping?

I'm trying to check for the existence of a table before dropping it. I've read through the API documentation for Doctrine_Table and I can't seem to find anything like this. Is there something I'm missing?

I've got code that looks like:

$table = new Doctrine_Table('model_name', $conn);

$export = new Doctrine_Export();

$export->dropTable($table->getTableName());

And the error I get when a table doesn't exist is:

Fatal error: Uncaught exception 'Doctrine_Connection_Mysql_Exception' with message 'SQLSTATE[42S02]: Base table or view not found: 1051 Unknown table

Thanks in advance,

Casey