А что мешает использовать writetext

WRITETEXT
Permits nonlogged , interactive updating of an existing text, ntext, or image column. This statement completely overwrites any existing data in the column it affects. WRITETEXT cannot be used on text, ntext, and image columns in views.

Syntax
WRITETEXT { table.column text_ptr }
[ WITH LOG ] { data }

Arguments
table.column

Is the name of the table and text, ntext, or image column to update. Table and column names must conform to the rules for identifiers. For more information, see Using Identifiers. Specifying the database name and owner names is optional.

text_ptr

Is a value that stores the pointer to the text, ntext or image data. text_ptr must be binary(16). To create a text pointer, execute an INSERT or UPDATE statement with data that is not NULL for the text, ntext, or image column. For more information about creating a text pointer, see either INSERT or UPDATE.

WITH LOG

Ignored in Microsoft® SQL Server™ 2000. Logging is determined by the recovery model in effect for the database.

data

Is the actual text, ntext or image data to store. data can be a literal or a variable. The maximum length of text that can be inserted interactively with WRITETEXT is approximately 120 KB for text, ntext, and image data.

Remarks
Use WRITETEXT to replace text, ntext, and image data and UPDATETEXT to modify text, ntext, and image data. UPDATETEXT is more flexible because it changes only a portion of a text, ntext, or image column rather than the entire column.

If the database recovery model is simple or bulk-logged, WRITETEXT is a nonlogged operation . This means text, ntext, or image data is not logged when it is written to the database; therefore, the transaction log does not fill up with the large amounts of data that often make up these data types.