Sending XML Document to Store Procedure

Question

I've got an app that downloads a text file from the web, turns it into an xml document using xmltextwriter. From here I want to pass the xml document to a stored procedure to update an SQL Server database. My quandry lies in how to pass the document. I don't want it to "touch the ground", meaning I want to take it straight from the download site and pass it (as a stream?) to the command object to the stored procedure without saving the xml document to a drive. I have the stored procedure receiving the document as an ntext parameter. Any help would be appreciated.