Is it ever appropriate to treat just the ipsilateral oropharynx and neck for head and neck cancer of unknown primary?  

I usually treat the bilateral neck, because half of the unknown primaries are likely in the base of the tongue, unless there’s a really good reason to reduce toxicity. And there usually isn’t.

Absolutely. The only time I treat contralateral neck electively is when there are multilevel ipsilateral adenopathy or very large single node with possible ECE. I have never had an isolated contralateral neck recurrence. 

This question was explored by the Danish and then in a series from Loyola.The Danish reviewed their experience in 350 pts and demonstrated that bilateral neck irradiation resulted in improved LRC and DSS. The Loyola group demonstrated c/l failure rate and mucosal primary emergence rates of 45% vs 15...

The key to success with unilateral neck only treatment in the management of squamous call ca of unknown primary is careful selection of patients after a comprehensive surgical work up that addresses the putative mucosal sites of origin. Only after such a work up can the case be staged as a pT0. Of l...