How do you approach elective cranial nerve target volumes for head and neck cancers to account for potential retrograde or anterograde spread along cranial nerves?

In general, I’m electively covering cranial nerve branches in the setting of an advanced skin cancer with at least microPNI, an adenoid cystic carcinoma, an advanced paranasal sinus tumor with micro or clinical PNI or a nasopharyngeal carcinoma with clinical PNI. Occasionally there’s an advanced gin...