iTextSharp PDF Creation

Question

I have a process where I am creating a PDF doc from data extracted from a MS SQL database. These are done with a person's name and I create a file in App_Data first with:

    string pdfTemp = System.Web.HttpContext.Current.Server.MapPath("~/Images/MTF.pdf");
    string filename = "~/App_Data/" + person.FirstName + "_" + person.LastName + "_MTF" + ".pdf";

    iTextSharp.text.pdf.PdfStamper stamper = new PdfStamper(reader, new FileStream(System.Web.HttpContext.Current.Server.MapPath(filename), FileMode.Create));

I then fill in the fields, close the stamper and send a stream to the view as well as save it to the database. I periodically try to delete any PDF file in the App_Data folder. If the PDF is being redone, sometimes the PDF in App_Data in still there for the person and it fails of course because is in use. How do you create a PDF without having to create a file first?

I've changed the approach according to a comment:

 MTFModel mtf = new MTFModel();
            mtf = GetMtfModelByPatientId(patientId);
            string pdfTemp = System.Web.HttpContext.Current.Server.MapPath("~/Images/MTF.pdf");
            iTextSharp.text.pdf.PdfReader reader = new PdfReader(pdfTemp);

            string pwd = System.Web.Security.Membership.GeneratePassword(20, 5);
            MemoryStream ms = new MemoryStream();
            iTextSharp.text.pdf.PdfStamper stamper = new PdfStamper(reader, ms);
            // stamp the form
            stamper.Close();
            return ms;

I can try to save it to the database:

            AddPatientMtf(mtd.ID, ms);

And then return the stream:

            return ms;

But the add patient function has to close the stream in order to save it.