Take a look at the Reports options under Tools.
Unfortunately, there is no report that includes a timestamp to
identify creation or modification date. (Or if there is, I haven't
found it...)
However, you could enter the date and time of each change in
the Comments section of each topic's Properties, and these comments
can print on the Topic Properties report (if selected in report
Options).
You may find that simply sorting the Topics list pod by Date
will give you the info you need to quickly determine which topics
may require updates.
I actually maintain a separate Excel spreadsheet, in which I
keep the following, by column:
Map ID
Form Name
Topic File Name
Topic Name
Latest Version
Last Revision Date
Notes (typically contains reason for last revision).
I update the spreadsheet each time I add a topic or edit an
existing topic. It can be tedious at times, but if I ever get hit
by a bus, it will be very handy for my successor. And the
development team likes to get an updated spreadsheet occasionally
so that they can do a sanity check on the MAP IDs.
Hope this helps! Welcome to the community.