First of all, never use Wikipedia as a source of information on stuff like this. Unless you are a physician, and can separate the wheat from the chaff yourself, rely upon your team. There is a fine line between being well informed (good) and substituting your judgment, based upon internet information(bad).
If you are treating at a CCC, adopting current practices, they will undoubtedly do an ND that preserves the maximum amount of functional tissue possible. Oftentimes, however, they do not know that until they get in there and see what is happening. Generally, the SCM, SAN and IJV are preserved unless they are structurally involved with tumor cells, or active disease is in close proximity and there is evidence of extracapsular spread.
In my case, I had a bilateral ND, due to the fact that my BOT tumor touched the midline. They removed nodes and connective tissue from Levels I through V, and both submandibular salivary glands, but kept the SCM, IJV and SAN intact.
Truly, the ND was the easiest part of treatment. Anytime they go into Level V, there is likely to be damage to the SAN and related nerves, which can cause shoulder/neck muscle issues, which I have, but is very manageable.
It seems that attitude toward ND is dependent upon whether you adopt the "go for broke" approach, throwing everything you can at the disease, or the "incremental" approach, doing the least invasive treatment providing the opportunity for cure.
That's a very personal decision, but one that needs to be made with the full informed opinions of your CCC treatment team. As others have said, I would not rely solely on a PET at this point, due to the high false positives, but your team will likely tell you that themselves.
Good luck.