user: Question: Who was the replacement for the Brussels team with a date of vacancy of 22 December 2007?
Columns: ['Team', 'Outgoing manager', 'Manner of departure', 'Date of vacancy', 'Replaced by', 'Date of appointment']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Sint-Truiden', 'Valère Billen', 'Quit', '18 September 2007', 'Peter Voets (caretaker)', '18 September 2007']
SQL:

assistant: SELECT "Replaced by" FROM "Table" WHERE "Team" = 'Brussels' AND "Date of vacancy" = '22 December 2007';