SYS.XMLTYPE field - would like to be able to edit field in query results

When I run my query and try to edit the XMLTYPE field, FILE_NAME, why does Toad tell me it is Read Only.

SELECT t.*, rowid FROM DS_OUTBOUND.DS_GBS_ACK_DATAXMLtmp t;

My Table:

CREATE TABLE DS_GBS_ACK_DATAXMLTMP
(
UNIQUE_ID NUMBER,
CLIENT_ID NUMBER,
CLIENT_NAME VARCHAR2(100 BYTE),
FILE_TYPE VARCHAR2(10 BYTE),
FILE_NAME VARCHAR2(255 BYTE),
FILE_DATA SYS.XMLTYPE,
STAGED_DATE DATE DEFAULT sysdate,
PROCESSED NUMBER DEFAULT 0,
PROCESSED_DATE DATE,
INSUREDCLAIMNUMBER VARCHAR2(4000 BYTE),
CLAIMREFERENCENUMBER VARCHAR2(4000 BYTE)
)

Toad doesn’t support editing of XMLTYPE. We would like to. We know it’s important. XMLTYPE in Unicode mode technically isn’t supported by the OCI. So we have to select XMLTYPE as CLOB just to be able to display it, and we can’t do updates that way. If/when a solution becomes available, we’ll make appropriate changes in Toad.