Should cN0 oral cavity cancers that are completely resected but have indications for RT ever receive elective nodal RT?

For the larger question of "should cN0 oral cavity cancers...ever receive elective nodal RT?", I base my decision-making on primary site location, depth of invasion, grade, perineural invasion and lymphovascular invasion. Floor of mouth primaries with >1.5mm depth of invasion should have a neck diss...