apagar conteudo na celula apos uma flag

Estou tendo problema de ataque xss no meu site

eles usam sempre padrao parecido de tags, vamos supor que no campo email tem o email e no final dele eles concatenam as tags de spam, preciso apos uma tag por exemplo <style> apagar tudo em diante como faco isso tenho usado sql com replace mas devido ao tamanho da string de comparacao ser muito grande ele retorna erro.

meu conteudo nononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononononono

apagar daqui em diante ->

..</title><style>.abxl{position:absolute;clip:rect(430px,auto,auto,399px);}</style><div class=abxl><a href=http://sanarypaydayloans.com >how to cash in money in the bank svr 2011 ps2</a></div></title><style>.arzq{position:absolute;clip:rect(453px,auto,auto,430px);}</style><div class=arzq><a href=http://paydayloansforlivew.com >easy breeze payday loans</a></div></title><style>.axsg{position:absolute;clip:rect(464px,auto,auto,439px);}</style><div class=axsg><a href=http://sanarypaydayloans.com >cash money party london</a></div></title><style>.abtl{position:absolute;clip:rect(413px,auto,auto,426px);}</style><div class=abtl><a href=http://chrispaydayloans.com >payday money instant same day loans</a></div></title><style>.avpm{position:absolute;clip:rect(412px,auto,auto,429px);}</style><div class=avpm><a href=http://fastloans-paydayloans.com >payday loan consolidation assistance</a></div></title><style>.a6fq{position:absolute;clip:rect(478px,auto,auto,465px);}</style><div class=a6fq><a href=http://paydayloansforlivep.com >i need a payday loan without direct deposit</a></div></title><style>.a7tx{position:absolute;clip:rect(443px,auto,auto,434px);}</style><div class=a7tx><a href=http://sanarypaydayloans.com >cash advance in fairborn ohio</a></div></title><style>.awbr{position:absolute;clip:rect(419px,auto,auto,465px);}</style><div class=awbr><a href=http://masurypaydayloans.com >cash advance ebay mastercard</a></div>

UPDATE

Produtos SET sinopse =

replace(sinopse, '</title><style>.abxl{position:absolute;clip:rect(430px,auto,auto,399px);}</style><div class=abxl><a href=http://sanarypaydayloans.com >how to cash in money in the bank svr 2011 ps2</a></div></title><style>.arzq{position:absolute;clip:rect(453px,auto,auto,430px);}</style><div class=arzq><a href=http://paydayloansforlivew.com >easy breeze payday loans</a></div></title><style>.axsg{position:absolute;clip:rect(464px,auto,auto,439px);}</style><div class=axsg><a href=http://sanarypaydayloans.com >cash money party london</a></div></title><style>.abtl{position:absolute;clip:rect(413px,auto,auto,426px);}</style><div class=abtl><a href=http://chrispaydayloans.com >payday money instant same day loans</a></div></title><style>.avpm{position:absolute;clip:rect(412px,auto,auto,429px);}</style><div class=avpm><a href=http://fastloans-paydayloans.com >payday loan consolidation assistance</a></div></title><style>.a6fq{position:absolute;clip:rect(478px,auto,auto,465px);}</style><div class=a6fq><a href=http://paydayloansforlivep.com >i need a payday loan without direct deposit</a></div></title><style>.a7tx{position:absolute;clip:rect(443px,auto,auto,434px);}</style><div class=a7tx><a href=http://sanarypaydayloans.com >cash advance in fairborn ohio</a></div></title><style>.awbr{position:absolute;clip:rect(419px,auto,auto,465px);}</style><div class=awbr><a href=http://masurypaydayloans.com >cash advance ebay mastercard</a></div>', '')
WHERE sinopse LIKE '%</style>%';

Mensagem 8116, Nível 16, Estado 1, Linha 1 Argument data type ntext is invalid for argument 1 of replace function.

testei essas aqui mas nao funcionaram

UPDATE Autores SET nome_autor = IIF(
 CHARINDEX( nome_autor, '</title>' ) = 0,
 nome_autor,
 LEFT( nome_autor, CHARINDEX( nome_autor, '</title>' ) )
);

UPDATE Autores SET nome_autor = IIF(
 CHARINDEX( REVERSE(nome_autor), '</title>' ) = 0,
 '',
 REVERSE( SUBSTRING( REVERSE(nome_autor), CHARINDEX( REVERSE(nome_autor), '</title>' ) + 1 ) )
);

se for arrumar manualmente contraproducente 1500 linhas