Head and neck sarcoma. Target volume delineation.

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Kroll2013

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Dear friends, is there any guidelines / publications for the target volume delineation of HAN STS, in the setting of neoadjuvant CRT for an inoperable lesion?
Tx

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I don't know of anything in specific. But respect the anatomic boundaries of compartments and I think your contours will end up looking similar to a H&N SCC plan - just add a sup/inf margin (3cm for low grade, 4cm for high grade is what I use) and that margin respects anatomical planes. Axially, your margin will be very tight, but basically encompass a standard H&N volume that is site-dependent.

The more important question here IMO is - what dose are you planning to go to? You stated the lesion is inoperable..is the plan to go to 40-50Gy and reassess? Without surgery, this is probably incurable..could be some tough decisions regarding the final dose and whether to continue chemo down the road..
 
I don't know of anything in specific. But respect the anatomic boundaries of compartments and I think your contours will end up looking similar to a H&N SCC plan - just add a sup/inf margin (3cm for low grade, 4cm for high grade is what I use) and that margin respects anatomical planes. Axially, your margin will be very tight, but basically encompass a standard H&N volume that is site-dependent.

The more important question here IMO is - what dose are you planning to go to? You stated the lesion is inoperable..is the plan to go to 40-50Gy and reassess? Without surgery, this is probably incurable..could be some tough decisions regarding the final dose and whether to continue chemo down the road..
Exactly.
I plan to give 50Gy than reassess for resecability. If still inoperable i will try to escalate till 60-66 Gy depending on the tolerance.
Thank you a lot for replying.
 
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Exactly.
I plan to give 50Gy than reassess for resecability. If still inoperable i will try to escalate till 60-66 Gy depending on the tolerance.
Thank you a lot for replying.
Normally, you'd want to go to 70 Gy for unresectable scc of the H&N. Sarcoma should receive at least that much, maybe even more
 
I agree with everything else that was said. I'd add:

I like to follow RTOG 0630 margins. I know that's for extremeties, but I'd probably follow them here where it makes sense to do so. It's going to be tricky considering all the sensitive structures. Given that this is basically a palliative case (see below), I'd be very cautious to preserve quality of life.

Lymph nodes negative I take it? Would consider some degree of nodal coverage for the SCARE based on location of the primary. If it isn't a SCARE sarcoma and no evidence of LAD, forget about it.

Most sarcoma subtypes don't usually shrink quickly with radiation either, so the odds of this magically becoming resectable at the end of RT, especially after 50 Gy, are very slim. Whatever you do, don't break this patient's radiation for a few weeks for reasons other than toxicity while you try to get a surgeon to commit to not cutting on this poor soul. Thus, this is essentially a palliative situation. I imagine you've imaged the lungs as well? I'd be less aggressive if there are lung mets. Otherwise I agree with 70 Gy.

Why the field hasn't figured out a concurrent chemo regimen in these situations is beyond me. Something sequential makes sense to shrink. The chemo regimen here seems like a bit of a dark art based on limited data and the subtype of sarcoma. Still, I'd strongly consider sequential chemo then radiation, and if god smiles on this person maybe that could get it to resection over radiation alone. Chemo first is better in this scenario given the radiation fibrosis that will develop a few weeks after RT. Though you did say "neoadjuvant CRT", so I wonder what you're using.
 
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I don't know of anything in specific. But respect the anatomic boundaries of compartments and I think your contours will end up looking similar to a H&N SCC plan - just add a sup/inf margin (3cm for low grade, 4cm for high grade is what I use) and that margin respects anatomical planes. Axially, your margin will be very tight, but basically encompass a standard H&N volume that is site-dependent.

The more important question here IMO is - what dose are you planning to go to? You stated the lesion is inoperable..is the plan to go to 40-50Gy and reassess? Without surgery, this is probably incurable..could be some tough decisions regarding the final dose and whether to continue chemo down the road..

Definitely agree with respecting anatomic boundaries. I guess it really depends on the actual location, is this like a nasopharyngeal or posterior pharyngeal wall STS, or is this a superficial neck (like arising in the SCM or something?). 3-4cm is used for an extremity, but would need to be tighter for true head and neck site. For intact sarcoma need >66Gy, also of course remember to plan for your final dose/conedown/SIB upfront even if you might not end up making it, worst thing would be to plan to 50 or something and then realize that you've already reached tolerance on a structure limiting any further dose. I would favor concurrent chemoRT versus induction chemo but depends on histology. Would consider doing simultaneous integrated boost taking the GTV in 2.2Gy or 2.12Gy fractions. With chemoRT you could at least plan for definitive intent, RT alone would be palliative...
 
Do you have data for this? Last time I reviewed this topic, there was minimal data for concurrent chemoRT in sarcoma.

Yeah depends on histology, there is data of course for concurrent chemoRT for Rhabdomyosarcoma which is technically STS (In which case >66Gy would not be appropriate..) For other high grade STS there is retrospective data from DeLaney et al, from MGH using neoadjuvant chemoradiation in an interdigitated approach, but admittedly this was for large high-grade extremity soft tissue sarcomas. A subsequent RTOG study did show significant toxicity with concurrent chemoradiation for STS, so certainly need to be cautious. I would still consider it in the absence of other great options, and I agree induction chemo would be more standard approach. There is no high level evidence to guide management in these cases so need to extrapolate and use best principles. There is some thought that high grade sarcomas or those with more of a "round cell component" may derive more benefit from chemo.. so depends on a number of factors including histology.
 
Personally, I disagree with sequential chemoRT. This person has a local problem - one that is unlikely to have a favorable outcome - but their one shot is to downstage this thing and get to surgery. Chemo has very low activity in almost all sarcomas and the response rate/control locally I expect to be much better with RT than chemo. I've personally seen sarcomas progress right through chemo, killing with kindness as the surgical bridge is definitively burned.

I agree with some sort of altered fx >2Gy if RT alone or chemoRT - granted the chemoRT data is not great, but you're firing with all barrels at this with no regrets.

At the end of the day, we're all making this up based on limited data. Be frank about that with your patient, present some options, go with your gut and oncologist common sense in which way to nudge them.
 
Dear friends, is there any guidelines / publications for the target volume delineation of HAN STS, in the setting of neoadjuvant CRT for an inoperable lesion?
Tx
what's the histology?
 
I know everyone's disagreeing with me on sequential chemoRT so I guess I should explain. There are only two chemotherapy regimens I know work well with adult STS (excluding RMS)--taxane combinations and ifos combinations. I'm probably forgetting about some relatively esoteric regimens for selected subtypes (e.g. VDC). None of these would I give with concurrent 45-70 Gy to the neck. I guess you could get creative and do induction TPF->PF or extrapolate from pediatric regimens (emphasis on the induction bit for me). It would be pretty weird though. I'm not really aware of single agent platinum or even platinum + 5-FU having much activity in sarcoma. I'm not aware of certuximab having activity in sarcoma. So this is why I'm throwing out concurrent chemo.

I guess at the end of the day this is an experience/institution thing. At our instituion we generally treat these with sequential chemo then RT. My belief, based on no evidence, is that this has more chance of responding quickly to proper chemo than proper RT, especially by 45-50 Gy. I don't think I've ever seen an adult STS (again excluding RMS) respond significantly and immediately by that dose. What I see much more frequently on the outside is a gap in RT at 45-50 Gy while everyone prays that it's now magically resectable, it still isn't, and the patient gets another 20 Gy after the tumor has had a few weeks to repopulate.

If someone wants to propose something reasonable for concurrent in the more common adult STS subtypes, I'd be happy to hear it. I think this is an area ripe for research.
 
Interesting discussion!

Agree the histology here matters - it would be nice to know what we are dealing with?

Neuronix - I have used concurrent Taxol in the past for H&N sarcomas all the way to 70Gy. Not super awesome chemo, but the 2 times I have done that they have at least gotten through treatment.

I see your point though and honestly I can't remember ever seeing a sarcoma that was initially unresectable and then converted to truly resectable by either RT or chemoRT (although aggressive local treatment may twist a surgeon's arm to give it a try..but who knows if you're doing your patient a service or disservice). However, I have seen patients progress locally while getting just chemo and my sense is just that XRT makes more sense to try to stabilize things locally - either for palliation or for curative intent.
 
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This is a good discussion! :) Totally agree that more research is need in this area, and something that Rad Onc's should probably lead. Fortunately secondary malignancies are very rare, but when they do occur they tend to be sarcomas. Given this we should own up novel ways to manage or salvage de-novo sarcomas or secondary sarcomas... I guess we are all waiting on the histology for this case!
 
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