What is the significance of PNI in oropharyngeal cancer?

Perineural invasion (PNI) is a risk factor for local recurrence for oropharyngeal cancers (Routman et al., PMID 28847412). I have infrequently seen gross named nerve invasion with OPX tumors, so it is usually an intermediate risk factor. When named nerve invasion does occur, it is generally hypoglos...

Indication for postop RT if operated.