在PHP中使用SOAP MTOM发送文件

I need to create a SOAP request using MTOM. I have tried modifying __doRequest, but without any success. Is there any way to implement this in PHP?

Below is the required request format,

 <soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope" xmlns:ser="http://service.example.com/">
   <soap:Header/>
   <soap:Body>
      <ser:ImportInvoice>
         <ImportParams>
            <Notes>?</Notes>
            <XMLFile>cid:574901819478</XMLFile>
         </ImportParams>
      </ser:ImportInvoice>
   </soap:Body>
</soap:Envelope>