How would you approach the parotid volume for a PET avid intra-parotid node when planning definitive chemo radiation for a locally advanced squamous cell carcinoma of the oropharynx?

Beware Warthin’s tumor! I have a low threshold to biopsy given the quite small (but of course not zero) risk of parotid metastasis in the typical patient.

Parotidean metastases of OPC may be the result of massive ipsilateral level II involvement causing retrograde lymphatic flow, or extension of the primary to the nasopharynx (the eustachian tube has some lymphatic channels to the parotid, resulting in rare parotidean metas in NPC cases). If these are...

I would biopsy the PET avid area. I have seen Warthin’s tumors concurrent with oropharyngeal primaries, and they look like intraparotid lymph nodes. In our cases, a biopsy confirmed Warthin tumor and allowed sparing of the parotid.

Interesting question. I don’t think I’ve seen that in over 40 years. Blast the primary, neck, and parotid with chemoRT and resect what’s left.

For argument's and provocativeness's sake, and given Drs. @Dr. First Last and @Dr. First Last's answers above...

"I don’t think I’ve seen that in over 40 years"...
"...quite small (but of course not zero) risk of parotid metastasis in the typical patient..."

Let us assume that the rate of intraparotid ...

The point about a Warthin's tumor is a good one. I’ve seen parotid Mets in 3 NPC patients but not OPX.