H&N Unknown Primary Case

[Gfunk6]

63M lifelong non-smoker notices a L neck mass.

FNA of mass = non-diagnostic
MRI Neck = x2 necrotic L level II LN (2.4 cm and 1.4 cm)

Excisional biopsy of larger LN = poorly differentiated SCC, p16 positive

PET/CT = x3 FDG-avid L neck LN (biopsy bed, 2 cm, 0.9 cm); sub-cm LN in posterior neck (?reactive vs. involved); no primary identified

ENT fiberoptic exam = no primary identified
My fiberoptic exam = no primary identified

EUA w/ bilateral tonsillectomies + site-directed biopsies of base of tongue and nasopharynx = no evidence of malignancy

Final stage = cTxN2bM0

-----------------------------------------------------

My plan: IMRT + concurrent CDDP (d1, d22, 100 mg/m2)

Gross nodal disease (69.96 Gy/33 fx)
L Level IB, II, III, IV,V (59.4 Gy/33 fx)
R Level IB, II, III, IV, V + NPx + BOT + tonsillar bed (54 Gy/33 fx)

I'm leaning towards sparing the larynx and hypopharynx as statistically they are very unlikely to be involved.

Following-treatment, re-image in 2 months and perform salvage neck dissection if appropriate.

Any thoughts or comments would be appreciated.

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[deleted4401]

I'd do everything exactly as you are - workup, doses, fractionation, volumes, sparing larynx/HP/OC.
The only thing you didn't detail was how high on the contralateral side. I'd presume you will go higher up on ipsi - i.e. to BOS to include junctional/retrostyloid LNs, while on the contra side go to C1-C2 interface so you can spare that 'rotid.
-S

 

[medgator]

63M lifelong non-smoker notices a L neck mass.

FNA of mass = non-diagnostic
MRI Neck = x2 necrotic L level II LN (2.4 cm and 1.4 cm)

Excisional biopsy of larger LN = poorly differentiated SCC, p16 positive

PET/CT = x3 FDG-avid L neck LN (biopsy bed, 2 cm, 0.9 cm); sub-cm LN in posterior neck (?reactive vs. involved); no primary identified

ENT fiberoptic exam = no primary identified
My fiberoptic exam = no primary identified

EUA w/ bilateral tonsillectomies + site-directed biopsies of base of tongue and nasopharynx = no evidence of malignancy

Final stage = cTxN2bM0

-----------------------------------------------------

My plan: IMRT + concurrent CDDP (d1, d22, 100 mg/m2)

Gross nodal disease (69.96 Gy/33 fx)
L Level IB, II, III, IV,V (59.4 Gy/33 fx)
R Level IB, II, III, IV, V + NPx + BOT + tonsillar bed (54 Gy/33 fx)

I'm leaning towards sparing the larynx and hypopharynx as statistically they are very unlikely to be involved.

Following-treatment, re-image in 2 months and perform salvage neck dissection if appropriate.

Any thoughts or comments would be appreciated.

Agree with your plan. p16 and his history pretty much tells you that it's most likely an OP primary, so some might even exclude the NP but I would probably include it. Some might include the putative primary sites in the intermediate dose volume (59.4 Gy) but that's probably style points more than anything else

 

[Cancerdancer]

What about treating with RT alone ala RTOG 00-22. With p16 positivity, given all then uncertainties in how to treat HNUP, would lean towards the minimalistic side of things, whereas your volumes, dose, and inclusion of chemo are towards the heavier end of the spectrum.

FWIW--PMID 20622648

Also, unless they are Asian, we never include the nasopharynx.

Your treatment seems entirely reasonable, but to start my answer as such isn't very interesting or fun

 

[medgator]

I'd do everything exactly as you are - workup, doses, fractionation, volumes, sparing larynx/HP/OC.
The only thing you didn't detail was how high on the contralateral side. I'd presume you will go higher up on ipsi - i.e. to BOS to include junctional/retrostyloid LNs, while on the ipsi side go to C1-C2 interface so you can spare that 'rotid.
-S

You meant contra I think, but a good point to bring up for sure when doing your IMRT planning

 

[deleted4401]

You right, Medgator, edited that.
0022 didn't include any N2s, not even N2a, but I could see skipping the juice.
I never seen omission of NP ... PMH, UFL, Danish studies, and modern IMRT always include. But, I guess you can make the point that if p16 positive and EBV negative, low risk of NPC.
I'd take it all the way up. It's not like a true nasopharynx cancer field so you don't have to include BOS/Clivus/Sphenoid/Paraphyngeal etc, so not winning too much with toxicity, like with omission of larynx/OC.

 

[Cancerdancer]

0022 didn't include any N2s, not even N2a, but I could see skipping the juice.

Per the Eisbruch 00-22 paper:

Eligible patients had clinical early-stage (T1–2, N0–1, M0) oropharyngeal squamous cell carcinoma in which primary RT was indicated and in which both sides of the neck were judged to be at risk of metastatic disease. Patients with small N2 disease by imaging were also eligible.

If you think about it, including small N2b (2 nodes each 1.2 cm, for example) makes more sense than including N2a as a small N2b should not be any less responsive to the same dose as a N1 patient...I'm sure that's why it was written that way. It doesn't say N2a b/c you can't have a 'small N2a'...

 

[Gfunk6]

I'd do everything exactly as you are - workup, doses, fractionation, volumes, sparing larynx/HP/OC.
The only thing you didn't detail was how high on the contralateral side. I'd presume you will go higher up on ipsi - i.e. to BOS to include junctional/retrostyloid LNs, while on the contra side go to C1-C2 interface so you can spare that 'rotid.
-S

Good point. On ipsi I would go up to retryopharyngeal LN and on contra I would go up to II (probably omit IB).

Your treatment seems entirely reasonable, but to start my answer as such isn't very interesting or fun

Agree with you there.

 

[temujim]

Suggestions:

I would not treat the contralateral level IB or V. Consider sparing ipsi IB if no gross LN on the border. Try and keep submandibular gland(s) below 39 mean, makes a big difference when you can.

Cover retrostyloid space ipsi. I agree with covering NPx - Eisbruch has a series of p16+ NPx.

Good luck.

My plan: IMRT + concurrent CDDP (d1, d22, 100 mg/m2)

Gross nodal disease (69.96 Gy/33 fx)
L Level IB, II, III, IV,V (59.4 Gy/33 fx)
R Level IB, II, III, IV, V + NPx + BOT + tonsillar bed (54 Gy/33 fx)

I'm leaning towards sparing the larynx and hypopharynx as statistically they are very unlikely to be involved.

Following-treatment, re-image in 2 months and perform salvage neck dissection if appropriate.

Any thoughts or comments would be appreciated.

 

[ShirleyT]

Can argue to include or not to include concurrent chemo in this case. The concurrent chemo will definitely increase toxicity and local control will be good with radiation (especially p16 positive, non bulky and can always add neck dissection if needed). Where I am at, most of the patients like this would get concurrent chemo once anyone is labeled N2b though.

Here is a retrospective analysis on concurrent chemo in unknown primary (showed no benefit)
http://www.ncbi.nlm.nih.gov/pubmed/20933340.

Agree with volumes and sparing larynx/hypopharynx. Are you doing imrt the whole way or matching with ap scv field? I usually match with ap scv field to block larynx to maximum extent, even if i junction through gross nodes and i just look at the junction dosimetry carefully. Interesting comments on submandibular sparing, i have not been doing that, but that is something worth looking into...

 

[deleted4401]

I've never been able to do the matched AP field. None of the attendings I worked with in residency did it that way, and I tried to do it here in my practice and the physics/dosimetrists/therapists were very uneasy. Physics hate when I try to match anything because of uncertainty, and the rest of the squad didn't like the matching and felt it took longer. I didn't push.

I was also going to mention skipping the IBs ... There's a good JHH series on this: http://www.ncbi.nlm.nih.gov/pubmed/19131181, and they say you can omit bilateral IB, even on the clinically N+ side, as long as radiologically negative (obviously). I haven't been doing it regularly, though, can't get it out of my head that if you have + level IIs, you should include IB, but dogma is silly, I guess.

 

[temujim]

UAB published (PMID:15465215) a nice technique for reducing the uncertainty at the IMRT/LAN field match. I used this for a while because there are advantages to laryngeal sparing, but stopped when we switched to arcs...

I've never been able to do the matched AP field. None of the attendings I worked with in residency did it that way, and I tried to do it here in my practice and the physics/dosimetrists/therapists were very uneasy. Physics hate when I try to match anything because of uncertainty, and the rest of the squad didn't like the matching and felt it took longer. I didn't push.

I was also going to mention skipping the IBs ... There's a good JHH series on this: http://www.ncbi.nlm.nih.gov/pubmed/19131181, and they say you can omit bilateral IB, even on the clinically N+ side, as long as radiologically negative (obviously). I haven't been doing it regularly, though, can't get it out of my head that if you have + level IIs, you should include IB, but dogma is silly, I guess.

 

[medgator]

I've never been able to do the matched AP field. None of the attendings I worked with in residency did it that way, and I tried to do it here in my practice and the physics/dosimetrists/therapists were very uneasy. Physics hate when I try to match anything because of uncertainty, and the rest of the squad didn't like the matching and felt it took longer. I didn't push.

I was also going to mention skipping the IBs ... There's a good JHH series on this: http://www.ncbi.nlm.nih.gov/pubmed/19131181, and they say you can omit bilateral IB, even on the clinically N+ side, as long as radiologically negative (obviously). I haven't been doing it regularly, though, can't get it out of my head that if you have + level IIs, you should include IB, but dogma is silly, I guess.

Honestly as long as you contour the larynx and assign it constraints, I think full IMRT without a LAN is fine

 

[Palex80]

Your plan sounds reasonable and its surely an option, but:

I usually ask the patients in cases like this, what kind of treatment they want.
I try to explain to them the differences in chance of controlling the tumor and toxicity in 3 different scenarios:
a) treat only the involved neck side
b) treat both neck sides
c) treat both neck sides and any suspected sites of primary tumor.

I have seen patients, who decided not to receive elective irradiation of the contralateral side or suspected sites of primary tumor.

I probably wouldn't give chemo.

 

[Pewl]

I remember seeing a Nancy Lee talk where she recommended omitting the upper half of the Level IIA/IIB lymph nodes on the contralateral N0 side, assuming it's an oropharyngeal origin. But then I guess you don't know if this is oropharyngeal in origin or not..

 

[medgator]

I remember seeing a Nancy Lee talk where she recommended omitting the upper half of the Level IIA/IIB lymph nodes on the contralateral N0 side, assuming it's an oropharyngeal origin. But then I guess you don't know if this is oropharyngeal in origin or not..

You pretty much have to make an educated guess based on things like HPV and EBV status. If it's HPV+ and EBV-, probably leans towards an OP origin.

 

[jinbo]

Share a similar case​

57M with a L neck mass(Level III).


Excisional biopsy of L neck mass = SCC



PET/CT = FDG-avid L neck LN (biopsy bed, [FONT=&#23435]3.[FONT=&#23435]×4cm,.SUV 18.3,); left pyriform sinus FDG-avid(SUV 3.2);


My fiberoptic exam = no primary identified include the pyriform sinus

The pts declined bilateral tonsillectomies
Final stage = cTxN2aM0
The pts received four cycle TP(Docetaxel+DDP) regimen and the neck mass approach CR. Then he came to our department​

My plan: IMRT​

Gross nodal disease (66Gy/33 fx)
L Level III (59.4 Gy/33 fx)​

NPC+ hypopharynx+ oropharynx (59.4 Gy/33 fx)


L II, IV,V+ R Level II, III, IV (50.4Gy/28fx)

Because of left pyriform sinus FDG-avid(SUV 3.2,authough fiberoptic exam show nothing here ) , I include hypopharynx as target.​

Any thoughts or comments would be appreciated. ​

 

[Gfunk6]

I think it will be really morbid to treat the patient's entire pharyngeal axis to 60 Gy. You did not explicitly mention the larynx as a target but it will be difficult to avoid significant doses to it if you are treating the hypopharynx.

Here are a few thoughts:

1. Did the patient have any risk factors (smoking/drinking)? Was his LN p16 positive?
2. Did he have a pre-chemo ENT evaluation with fiberoptic exam?
3. What does the radiologist have to say about the pre-chemo FDG-avidity in the L hypopharynx?

What I'm getting at is you may be able to treat this like a hypopharynx primary rather than an unknown primary. However, I'm not sure if you really have enough information to make such a leap of faith.