Using aggregate rollup data

I am using a query for totals using group by with roll up.  The query looks like this:

SELECT COALESCE(CAST(A.TopicID AS varchar(2000)), 'Report Total:') as 'Conference', COUNT(*) AS 'Number of Entries', A.TopicName, SUM(A.Amount) AS Sum FROM vwApplication A INNER JOIN Topic B ON A.Topic = B.Topic INNER JOIN ConfCity C ON B.ConfCityFK = C.ConfCityKEYID WHERE MoneyReceived = 1 AND Amount > 0 GROUP BY A.TopicID WITH ROLLUP

dataset = Conference              #entries                   Sum
                       44                               4                            4500
                       45                                5                            4600

I would like to pull the name associated with this TopicID Column

Any help with this would be greatly appreciated.