T4N0 buccal SCC and ENI

[Ray D. Ayshun]

All, figured I'd break the nonclinical string of threads and ask if anyone would do ENI in a patient with a big buccal squam resected to negative but close margins with PNI, no LVSI. T4 as it was invading the mandible. Patient had an ipsi level 1-3 dissection and contra 1 and 2. Wondering if anyone would still go after the nodes or just treat the operative bed. Current plan is to treat Ipsi neck.

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[Palex80]

I would do ENI.
I would discuss deescalation with ipsilateral nodal RT if the tumor was well lateralized and the patient would be interested in that, but there is a (small) risk for contralateral failure.

 

[OTN]

I would as well. You get one good shot in oral cavity cancer, so I usually like to use all the bullets I can.

 

[TheWallnerus]

Adjuvant chemoRT or just RT?

 

[Ray D. Ayshun]

Adjuvant chemoRT or just RT?

Just RT. Margins were good. Had a partial mandibulectomy and bone/skin graft etc.

 

[RickyScott]

Buccal mucosa are awful, but primary pattern of failure will be in the oral cavity. Would treat ipsilateral neck 1-3. Put in an obtutator to move tongue.

 

[thecarbonionangle]

“Classical approach” would be to treat ENI. Adam Garden just recently posted about this on mednet. There is retrospective evidence from washu to avoid radiation to the pN0 neck. However, Garden states he still treats bilateral/unilateral neck at least and didnt seem like he had switched over. I agree with other posters, i am general scared of OC. I dont play around with it. Bilateral neck and primary tumor bed for me. I dont think ipsi neck is “wrong” i just likely wouldn’t do it.

 

[communitydoc13]

Adjuvant chemoRT or just RT?

Good question, T4 is the ENE of primary disease. No right answer here.

Significant risk of discovering lung mets in the next 6 mos.

 

[deleted1111261]

“Classical approach” would be to treat ENI. Adam Garden just recently posted about this on mednet. There is retrospective evidence from washu to avoid radiation to the pN0 neck. However, Garden states he still treats bilateral/unilateral neck at least and didnt seem like he had switched over. I agree with other posters, i am general scared of OC. I dont play around with it. Bilateral neck and primary tumor bed for me. I dont think ipsi neck is “wrong” i just likely wouldn’t do it.

Yeah, same.

When I'm considering ipsi neck in a patient that historically was treated bilaterally (mostly pN0 oral cavity cases), gotta think of what we are sparing. I believe there was a recent bilateral vs unilateral neck study (RCT) that didn't show a whole lot of difference in toxicity/QOL. I'll look for it.

If considering ipsi, what are you trying to spare? I would think ..

- contra parotid - if it's oral cavity, I can cheat and start below parotid
- contra submandibular - this can't be spared unless you omit treating contra side
- oral cavity itself - depends on situation, but if it's the tongue it is going to be target. If it's buccal, well, yah ipsi will help spare the OC.

I'd probably do bilateral, but start below the parotid and do I, part of II, III, IV

 

[Ray D. Ayshun]

Was buccal mucosa, so as well-lateralized as you can get.

 

[TheWallnerus]

Was buccal mucosa, so as well-lateralized as you can get.

I think the main issue as to why I’d lean bilateral ENI is they did a neck dissection on both necks. So not only were they worried, they also upset the lymphatic apple cart.

 

[Ray D. Ayshun]

I think the main issue as to why I’d lean bilateral ENI is they did a neck dissection on both necks. So not only were they worried, they also upset the lymphatic apple cart.

I'd be worried if they hadn't done bilateral. I'd definitely treat contra neck of no contra dissection, but am leaning towards not treating since there were overall favorable node-involvement findings (negative nodes, no LVIS). I say this to play devil's as advocate. While it may not be brutally toxic to treat both sides, it will be more toxic.

 

[madchemist89]

Radiation is brutal.

 

[temujim]

All, figured I'd break the nonclinical string of threads and ask if anyone would do ENI in a patient with a big buccal squam resected to negative but close margins with PNI, no LVSI. T4 as it was invading the mandible. Patient had an ipsi level 1-3 dissection and contra 1 and 2. Wondering if anyone would still go after the nodes or just treat the operative bed. Current plan is to treat Ipsi neck.

Will go against the grain. If a good neck dissection (>15 on each), would only treat the primary.

 

[RadOncDoc21]

Head and neck elective volumes is the worst! Next question with a million answers… what’s the dose flavor for the 2-3 different SIB vs sequential schemes? Not necessarily in this case but in head and neck cancers in general. The longer I practice, the more I realize how much subjectivity is in our field.

I believe we shouldn’t take anything we do too seriously because we will always find a counter argument to our most basic beliefs.

 

[TheWallnerus]

Head and neck elective volumes is the worst! Next question with a million answers… what’s the dose flavor for the 2-3 different SIB vs sequential schemes? Not necessarily in this case but in head and neck cancers in general. The longer I practice, the more I realize how much subjectivity is in our field.

I believe we shouldn’t take anything we do too seriously because we will always find a counter argument to our most basic beliefs.

50 Gy to everything to start, then replan/rescan/boost the primary site region with 16 Gy because the T4 earns my respect

I never* do SIB anymore

 

[RickyScott]

Will go against the grain. If a good neck dissection (>15 on each), would only treat the primary.

Logically, I think you are right, but hard to treat the primary without treating some of level i and 2, so may as well at least treat those.

 

[sirspamalot]

Never do SIB for general H&N? I almost -always- do SIB unless postop or giganormous bulky tumors ie out of control leading to massive OAR exposure.

To each their own.

 

[deleted1111261]

I stopped SIB as well

 

[taserlaser]

I just sent off volumes for a definitive H&N merkel cell. I had a hard time coming up with some SIB doses that would make sense >60 Gy to primary and maintain >2 Gy/fr. That, and expecting the tumor to just melt. Seq boost on that one it was

 

[Ray D. Ayshun]

Why'd people stop sib? Works well post-op with 60/30 and 54/30.

 

[deleted1111261]

The Todd has a nice post on it on MedNet.

I’ve switched over based on what he said

- the low risk area gets a break; my and other anecdotes suggest this lowers acute and post acute skin and mucosal toxicity

- replanning is way easier if you choose to do that and can just schedule it, as so many of these are now HPV positive and melt

- I’m pretty sure 1.6 is fine, but in case if its not, SEQ keeps all doses the same

- for re RT, it’s easier to understand the doses to the OARs when all at same dose per fraction

SIB not bad. The sole benefit I see is convenience of tx planning. I see slight advantage for SEQ.

I brought this up to chair at Tata, he agreed. They had some internal data with worse thyroid toxicity with SIB. But, they can’t do SEQ because of throughput.

 

[Palex80]

The counterargument against sequential boosts is that your first prescribe a dose of 50 Gy to non-involved areas of the neck and the primary, but when you replan for the primary boost you en d up with a plan that delivers substantial incidental dose in those uninvolved areas too (the ones at the same level as the primary).
So in the end, with a sequential approach you end up overdosing some uninvolved areas.

 

[deleted1111261]

The counterargument against sequential boosts is that your first prescribe a dose of 50 Gy to non-involved areas of the neck and the primary, but when you replan for the primary boost you en d up with a plan that delivers substantial incidental dose in those uninvolved areas too (the ones at the same level as the primary).
So in the end, with a sequential approach you end up overdosing some uninvolved areas.

This is true. The conformality of the plan appears better with SIB. It still doesn’t seem to matter (anecdotal).

 

[TheWallnerus]

The counterargument against sequential boosts is that your first prescribe a dose of 50 Gy to non-involved areas of the neck and the primary, but when you replan for the primary boost you en d up with a plan that delivers substantial incidental dose in those uninvolved areas too (the ones at the same level as the primary).
So in the end, with a sequential approach you end up overdosing some uninvolved areas.

Nah

You don’t always end up with “substantial” doses to uninvolved areas; totally dependent on initial disease spatial configuration, admittedly. Devil in the planning details!


Also keep in mind those “uninvolved” areas (UAs) get 56 grays with SIB, but 50 with seq. Do the (acute toxicity radiobiological) math. I’d rather be a little less conformal with 50 to 600 cc of UAs vs conformal with 56 (or 56 sliding into 63) to 550 ccs.

 

[madchemist89]

The only way to avoid incidental dose to uninvolved areas is lots of replanning. I do SIB, which looks good upfront, but the patients lose weight, tumor shrinks, and parotids reduce in size secondary to rt. Normal structures move in to high dose areas. The only way around this is to replan. You end up with the same dosimetric uncertainties as sequentially planning.

 

[Ray D. Ayshun]

Fwiw, I only do sib in hn if 30 fx and post op with no gross disease. Only give <1.8 gy/fx for anal cancer and lymphomas.

 

[evilbooyaa]

Lots of great questions/discussion here.

All, figured I'd break the nonclinical string of threads and ask if anyone would do ENI in a patient with a big buccal squam resected to negative but close margins with PNI, no LVSI. T4 as it was invading the mandible. Patient had an ipsi level 1-3 dissection and contra 1 and 2. Wondering if anyone would still go after the nodes or just treat the operative bed. Current plan is to treat Ipsi neck.

Buccal is ipsilateral (TBAR) but I worry inT4 patients. But, they dissected contralateral neck. I'd be open to idea of sparing contralateral neck. Despite the Contreras phII study I would not be enthusiastic to skip ipsilateral coverage. Only 20% of the patients from that were OC, which we know is an independent poor prognostic factor. And we don't know how many of that 20% were T3-T4. I think like a T1-2N0 buccal squam yeah I'm probably down to skip ipsi neck. However, I don't think it's 'wrong' to omit RT to ipsi neck even in this situation. Probably worth a patient centered discussion if you think patient has the health literacy for it.

That being said, covering the primary resection area is going to cover most of level IB and II. I wouldn't do high level II even if covering nodes given pN0 which may let you spare ipsi parotid to mean < 26. So then you're adding the toxicity of ipsi level III and maybe IV given potential for skip mets from OC (unclear to me if that's just oral tongue that skip mets or anything in OC), which is less than covering IB and II (although not negligible).

I would do RT alone but I can see an argument for adding chemotherapy and going to 66Gy given OC + T4.

In terms of RT dosing, I only do SEQ if there's going to be a > 5Fx difference (say HPV+ OPhx where I'm doing 70 to gross dz and 50 to microscopic, maybe 30 to microscopic if you go by the MSKCC data). I get the concept of re-simming and re-planning for boosts based on weight loss, etc. etc. I just don't feel re-planning for 5Fx is worth the squeeze. 10Fx difference sure. If I was less busy and wanted to maximize RVUs, then sure, 50/60/70 sequential with re-plan for each one.

I like the Adam Garden approach - 60Gy to primary, 57Gy to dissected neck (ipsi I-III), 54Gy to undissected neck (ipsi IV), all in 30 fractions.

I think this is good reading for SIB vs SEQ in H&N cancer - various view points and similar discussion - theMednet

 

[SneakyBooger]

Tiny T4, I would treat only tumor bed.

Big T4 (as above), I would add ipsi ENI.

 

[sirspamalot]

#66/60/54 ....SIB for lyfe