Adenoid Cystic Carcinoma of the head and neck

[Treat]

For adjuvant treatment of a non-parotid primary site , would you always trace the nearby cranial nerve to the skull base?
Even if there was no gross or microscopic perineural invasion?

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[Palex80]

No, I wouldn't.

 

[Gfunk6]

Agree with Palex

 

[Brim]

Agree with Gfunk

 

[RadOncDoc21]

Agree with Brim

 

[seper]

Hate to break the consensus, but I would ALWAYS trace the cranial nerve to BOS for H&N Adenoid CCa. About 10-15 other RadOnc attendings that I know see H&N cancer would as well (East Coast major metro area).
Are there data on recurrence patterns to support that? Doubt.

 

[RadOncDoc21]

I always thought it had to involve a "named nerve" with careful review of the path report and discussion with the surgeon.

 

[seper]

That is correct for squamous cell cancer. Adenoid CCa is believed to be a uniquely neurotropic malignancy.

I always thought it had to involve a "named nerve" with careful review of the path report and discussion with the surgeon.

 

[medgator]

That is correct for squamous cell cancer. Adenoid CCa is believed to be a uniquely neurotropic malignancy.

Yup, also hematogenous, they can often develop lung/bone mets too. They generally don't have lymph node spread. Very different behavior as a whole vs traditional SCC (although really bad SCCs/bulky N3s met out to the lungs too.)

 

[Pewl]

I generally trace ACC to the base of skull only if a named nerve is involved. ACC's tend to recur locally quite a bit, though I've seen 1 or 2 lung met cases.

 

[thecarbonionangle]

isn't cylindroma notorious for spreading along nerve tracts microscopically, often much farther than the path may appear?

 

[stankem]

Yup, also hematogenous, they can often develop lung/bone mets too. They generally don't have lymph node spread. Very different behavior as a whole vs traditional SCC (although really bad SCCs/bulky N3s met out to the lungs too.)

http://www.ncbi.nlm.nih.gov/pubmed/25060927

This study somewhat challenges this paradigm - there may be a role for elective nodal based on these numbers

 

[Treat]

As always, all replies are much appreciated.

For those who replied no to my initial question, what if i flipped the question around - would you only treat if there was nerve involvement? What if there are risk factors eg large primary tumour?

 

[BobbyHeenan]

For adenoid cystic, I most often (and definitely would with just path PNI, even if not a named nerve) use an SIB plan and treat the operative bed/preop tumor area to 60 Gy @ 2 Gy/fraction and chase the nerve back to the skull base at 1.7 Gy/fraction (51 Gy). I don't usually treat elective lymph nodes.

I answered this way and contoured as such on a boards case and my examiner seemed very pleased with this plan, for whatever that's worth.

With that said, if there was absolutely no PNI noted on path, I don't think it's "wrong" to just treat the operative bed. I would take into account tumor size, margins, co morbidities, etc and make the call then. I feel more strongly about covering back to skull base with PNI, so kind of wishy-washy without it.