Remove column If value is null from dynamic pivot query in SQL Server

My Sql Query is :

        select * from tblFeesDetail

        DECLARE @DynamicPivotQuery AS NVARCHAR(MAX)
        DECLARE @ColumnName AS NVARCHAR(MAX)
        SELECT @ColumnName = ISNULL(@ColumnName + ',','')+ QUOTENAME(FeesDetail) FROM (SELECT DISTINCT FeesDetail FROM tblFeesDetail) AS FeesHead
        SET @DynamicPivotQuery = ';WITH CTE AS(SELECT fd.FeeCatID,ClassName,AdmissionNo,ReferenceNo,SName,FName,FeeCatName,FeesDetail,Amount FROM tblFeesDetail as fd inner join tblFeesCategory as fc on fd.FeeCatID=fc.FeeCatID inner join tblStdReg as sr on sr.ClassID=fc.ClassID inner join tblDefClass as dc on fc.ClassID=dc.ClassID)
                                  SELECT FeeCatID,FeeCatName,ClassName,AdmissionNo,ReferenceNo,SName,FName,'+@ColumnName+'FROM CTE
                                  PIVOT (MAX(Amount)
                                  FOR FeesDetail IN('+@ColumnName+')) p
                                  WHERE FeeCatID = ''5''
                                  ORDER BY FeeCatID DESC'
        EXEC(@DynamicPivotQuery);