Hi,
It is possible to monitor specific content on a website, this is defined when configuring the Web Application monitor in SCOM.
Here's a very simple guide on how to achieve this:
SCOM: Checking for a word on a webpage
The builtin web application monitors are however quite limited, you could also take a look at URL Genie over here:
https://monitoringguys.com/2015/05/04/urlgenie-management-pack-for-scom-an-easy-powerful-solution-for-bulk-website-monitoring/
(If the reply was helpful please don't forget to upvote or accept as answer, thank you)
Best regards,
Leon