CUP bilateral vs unilateral RT

[Ray D. Ayshun]

This patient

presented with a 4.5 cm right level 2 node, p16+. On resection and search for primary all that was found was a single 4.5 cm node with ENE. Wondering who would do unilateral RT.

---

Members don't see this ad.

 

[BobbyHeenan]

I've had similar cases over the years and struggled with what to do. I ended up doing bilateral and aggressively sparing/under covering around contralateral parotid. These patients have done well.

I think you can go either way here.

I'm also curious to hear about what volumes and dose (0-50 Gy?) people would use on the mucosal sites too.

 

[NotMattSpraker]

This patient
View attachment 395829View attachment 395830
presented with a 4.5 cm right level 2 node, p16+. On resection and search for primary all that was found was a single 4.5 cm node with ENE. Wondering who would do unilateral RT.

I would. To me its more of a discussion of involved field versus comprehensive RT. If you've done a really good search including with surgery, you could assume its a T0 and unilateral is reasonable. Contralateral neck is also very salvageable.

Im not sure it makes a lot of sense to treat bilateral necks but nothing in the oropharynx.

 

[madchemist89]

I treat per asco guidelines in this situation, which by and large allows for unilateral treatment in this situation.

 

[BobbyHeenan]

I treat per asco guidelines in this situation, which by and large allows for unilateral treatment in this situation.

yes that is true.

As I recall it is even equivocal on whether to cover mucosal sites too, correct (assuming they have extensive biopsies and/or tonsillectomies)?

 

[macstjo15]

I would treat bilateral neck for ENE

ASCO guidelines
Recommendation 4.8: Patients treated with primary radiotherapy for N3 and/or bilateral nodal involvement and/or clinical and/or radiologic evidence of ENE require bilateral neck treatment (Type of recommendation: evidence based, benefit outweighs harm; Evidence quality: intermediate; Strength of recommendation: strong).

 

[Ray D. Ayshun]

I would. To me its more of a discussion of involved field versus comprehensive RT. If you've done a really good search including with surgery, you could assume its a T0 and unilateral is reasonable. Contralateral neck is also very salvageable.

Im not sure it makes a lot of sense to treat bilateral necks but nothing in the oropharynx.

Sorry, would include unilateral oropharynx in elective volume. Though would consider entire BOT. Regarding post concerning ENE, I kind of agree. Except, firstly, there was no clinical or radiological ENE. Secondly, ENE is not mentioned in the p staging of p16+. Certainly, the trials incorporated the old staging, but it appears ENE isn't much of a prognostic indicator in p16+, which might suggest, contra neck is as low of a risk with or without. Ultimately was originally a cT0N2a oropharynx cancer. I'd probably have treated unilaterally sans surgery if T1N2a tonsil.

Edit: Also, ASCO's recs include considering unilateral RT if N2, but nothing about T0. My question is maybe asking 2 questions: Unilateral in any CUP? And, unilateral if clinically and radiographically negative ENE but pathological ENE?

 

[lilshopta]

I treat per asco guidelines in this situation, which by and large allows for unilateral treatment in this situation.

I think one of the criteria in asco guidelines is no ECE for unilateral radiation.

 

[madchemist89]

I didn’t see the ene. I would just treat unilateral and cover bilateral base of tongue.

 

[evilbooyaa]

Unilateral neck alone no mucosal sites for p16+ (assuming thorough surgical evaluation)

 

[macstjo15]

Sorry, would include unilateral oropharynx in elective volume. Though would consider entire BOT. Regarding post concerning ENE, I kind of agree. Except, firstly, there was no clinical or radiological ENE. Secondly, ENE is not mentioned in the p staging of p16+. Certainly, the trials incorporated the old staging, but it appears ENE isn't much of a prognostic indicator in p16+, which might suggest, contra neck is as low of a risk with or without. Ultimately was originally a cT0N2a oropharynx cancer. I'd probably have treated unilaterally sans surgery if T1N2a tonsil.

Edit: Also, ASCO's recs include considering unilateral RT if N2, but nothing about T0. My question is maybe asking 2 questions: Unilateral in any CUP? And, unilateral if clinically and radiographically negative ENE but pathological ENE?

The ASCO guidelines are specific for cancer of unknown primary: https://ascopubs.org/doi/pdfdirect/10.1200/JCO.20.00275

edit: if it's only pathologic ENE without clinical/radiological ENE, I'd agree unilateral RT would be reasonable

 

[medgator]

The ASCO guidelines are specific for cancer of unknown primary: https://ascopubs.org/doi/pdfdirect/10.1200/JCO.20.00275

edit: if it's only pathologic ENE without clinical/radiological ENE, I'd agree unilateral RT would be reasonable

Thanks. Didn't know this existed

 

[Ray D. Ayshun]

The ASCO guidelines are specific for cancer of unknown primary: https://ascopubs.org/doi/pdfdirect/10.1200/JCO.20.00275

edit: if it's only pathologic ENE without clinical/radiological ENE, I'd agree unilateral RT would be reasonable

Perfick. EOT...

 

[gmsquid]

Is it HPV dna positive? 40% of skin cancers are p16+

 

[Ray D. Ayshun]

Is it HPV dna positive? 40% of skin cancers are p16+

Yes, just short handing with "p16+"

 

[Palex80]

I individually discuss these approaches with each patient. There is no clear evidence on superiority/inferiority of each approach. The more comprehensively one treats, the more toxicity one produces. I tend to treat more limited in patients who are not super fit, elderly.
Another question: Concurrent Cisplatin because of the ENE? No patients with CUP were included in the landmark trials, but one could make the argument that there may be some benefit by adding it?

 

[evilbooyaa]

I individually discuss these approaches with each patient. There is no clear evidence on superiority/inferiority of each approach. The more comprehensively one treats, the more toxicity one produces. I tend to treat more limited in patients who are not super fit, elderly.
Another question: Concurrent Cisplatin because of the ENE? No patients with CUP were included in the landmark trials, but one could make the argument that there may be some benefit by adding it?

I would add Cis given our knowledge of ENE.

 

[temujim]

This patient
View attachment 395829View attachment 395830
presented with a 4.5 cm right level 2 node, p16+. On resection and search for primary all that was found was a single 4.5 cm node with ENE. Wondering who would do unilateral RT.

With ENE would treat CL neck. Could just do level 2 +/- 3.

Would treat tonsil/BoT, but low dose (30-46 Gy) to tonsil/BoT area.

 

[Haybrant]

4.5cm node is big. Search should include tors mucosectomy and bilat tonsil. If they didnt do that then its not enough of search ot be omitting bilat neck. Most primaries i believe are found now compared to the historical data

 

[temujim]

4.5cm node is big. Search should include tors mucosectomy and bilat tonsil. If they didnt do that then its not enough of search ot be omitting bilat neck. Most primaries i believe are found now compared to the historical data

I don't think lingual tonsillectomy adds much, particularly for HPV+. Question the value of palatine tonsillectomy as well, certainly bilateral.

 

[SneakyBooger]

I would do unilateral.

 

[Radonky]

I see these once in a while. I would treat ipsilateral BOT (lumpy bumpy appearance makes it hard to identify a tiny primary), 1b, 2-4, partially include 5. Contralateral would spare 1b and 5. I will typically include some of the RP ipsilaterally. Because I think the primary is probably in the BOT, if if there was ENE, I treat bilaterally, but this is controversial. Some HN attendings won't treat BOT, and some don't treat bilateral neck unless more obvious indications (soft palate invasion, >1cm involvement of BOT, etc). can do 50-54Gy on elective sites which include BOT and contralateral neck. I typically will boost ENE 63-66Gy. Looking forward to the day I can comfortably de-escalate.