My scan was done somewhere with a general radiologist. Will a sub-specialty review really add much?

A second opinion from a sub-specialty reviewer often adds value in three specific ways — structured application of staging and post-treatment frameworks (TNM, NI-RADS) that may not have been applied explicitly, focused attention on features that are clinically important but easy to underreport (perineural spread, subtle nodal change, deep extension), and structured comparison with prior imaging. Whether these additions change the clinical picture in a particular case depends on what the original report covered and how the treating team uses it.