You may be aware that SQL 2005 version can perform an optional computation a backup checksum on the backup stream; if page-checksum or torn-page information is present on a given page, when backing up the page, BACKUP also verifies the checksum and torn-page status and the page ID, of the page. SQL Server supports three types of checksums: a checksum on pages, a checksum in log blocks, and a backup checksum. When generating a backup checksum, BACKUP verifies that the data read from the database is consistent with any checksum or torn-page indication that is present in the database.
For that you have to mention CHECKSUM option within the BACKUP statement, this will enable the pages to be backed up as they exist and will not be modified by the backup. But keep in mind this will have slow generation of backup process in terms of performance, the throughput & workload are affected and don't forget to monitor the CPU to ensure no adverse impact in using them. Though this provides an improved error detection you can take up only after testing the process completely.
Also you could take up verification of backup using RESTORE VERIFY ONLY statement, as this will only checks for errors on the file but will not assure the backup is completely clean or the restore operation can be completed without any error. So taking advantage of the option to add