T2 vocal cord Ca

[Palex80]

Hello

I saw a patient with a quite large T2 vocal cord SCC with subglottic expansion but no supraglottic invasion.
The subglottic expansion is more or less the tumor "hanging" from the vocal cord into the subglottic space, there was no clear invasion described in the panendoscopy report. The tumor grows all the way to the anterior commisure, does not cross to the other side though. The arytenoid cartilage is reached but no involved.
CT staging is N0.
Would you electively treat lymphatics in a case like this?
I thought about positioning the patient with a bit more reclination than usual and treating level III. That should keep most of his submandibular gland out of the way.
I was wondering if I should treat level VI too... Or is this an overkill, since vocal cord tumors rarely metastasize and there is co cartilage invasion anteriorly?

And then I was thinking what I should boost. I was thinking of treating the entire larynx up to 60 Gy and then boost the affected area (with a margin).
I don't think I should treat the entire larynx in a case like this. Previous series did treat the entire larynx to the full dose, sparing out only the arytenoid cartilage for example if it was clearly not reached by the tumor, but I think it's kind of an overkill to treat the contralateral vocal cord to a definitive dose.
I actually wanted to do hyperfractionation, but the patient has to travel a bit to treatment, so I may end up doing a SIB and hypofractionating with 2.25 Gy/d.

I'd like to hear your thoughts!

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[nkmiami]

I wouldn't treat the nodes. I think standard over here would be a 5x5 or 6x6 field at 2.25, although, the last several years I have used IMRT to avoid carotids and skin toxicity (greater skin toxicity with just 2 opposed fields) I would just treat tumor plus margin.

 

[medgator]

, the last several years I have used IMRT to avoid carotids and skin toxicity

Some insurances won't pay for imrt in early stage disease

 

[thecarbonionangle]

Don't get cute and get your fingers burned. This doesn't sound very "T2N0". Obviously anecdotal, but I had a pt where something just told me it was "off" and PET-CT showed nodes even though CT was "negative" by criteria.

 

[nkmiami]

Some insurances won't pay for imrt in early stage disease

There is also a 3d- 4 field "diamond" approach
Exophytic tumor hanging into the subglottic space is better prognosis than infiltrative tumor. I think subglottic extension has to be greater than 1cm to matter prognostically.

 

[medgator]

There is also a 3d- 4 field "diamond" approach
Exophytic tumor hanging into the subglottic space is better prognosis than infiltrative tumor. I think subglottic extension has to be greater than 1cm to matter prognostically.

Yeah I think minimal extension is still T2 (i want to say 5mm or less)

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[Palex80]

Thank you for the responses!

 

[RSAOaky]

<5mm is still considered T2 and treated as such. If it is an exophytic tumor that is "hanging down" into the subglottic region then I wouldn't upstage it but if there is actual invasion into the subglottic larynx > 0.5cm I would treat lymph nodes. Ask your ENT to clarify the degree of involvement

 

[evilbooyaa]

Yeah I think minimal extension is still T2 (i want to say 5mm or less)

Sent from my SAMSUNG-SM-N910A using SDN mobile

Am I missing something? A glottic laryngeal cancer, if there's subglottic invasion, it's T2, period. Doesn't matter on 'extent of invasion' into subglottis. 5mm inferior to the glottis is considered the inferior border of the glottic larynx. If it goes past that inferiorly, it's T2. If it doesn't, it's T1 (just based on extension, assuming normal cord mobility)

I'm not as caught up on most recent laryngeal data to determine prognostic implications on distance (@nkmiami if you find a source I'd love the education). Treating nodes (besides level III and part of II that would be incorporated in opposed fields) would not be normal. Treating with IMRT and specifically avoiding lymph node coverage wouldn't be normal either.

Extrapolation of the Yamazaki data (remember that was only T1N0 SCC) suggests 65.2 in 2.25Gy/fx given extremely low likelihiood of lymph node involvement.

 

[nkmiami]

I agree that imrt is not standard, but it does help with skin toxicity and may help dose to carotid. I am not sure if a polypoid lesion hanging off the cord qualifies as subglottic extension vs tumor spreading along mucosa.

 

[BobbyHeenan]

Am I missing something? A glottic laryngeal cancer, if there's subglottic invasion, it's T2, period. Doesn't matter on 'extent of invasion' into subglottis. 5mm inferior to the glottis is considered the inferior border of the glottic larynx. If it goes past that inferiorly, it's T2. If it doesn't, it's T1 (just based on extension, assuming normal cord mobility)

I'm not as caught up on most recent laryngeal data to determine prognostic implications on distance (@nkmiami if you find a source I'd love the education). Treating nodes (besides level III and part of II that would be incorporated in opposed fields) would not be normal. Treating with IMRT and specifically avoiding lymph node coverage wouldn't be normal either.

Extrapolation of the Yamazaki data (remember that was only T1N0 SCC) suggests 65.2 in 2.25Gy/fx given extremely low likelihiood of lymph node involvement.

I typically for T2 (whether non-extensive supraglottic or subglottic extension) just stick to opposed ~6X6 fields with 65.25 @2.25 Gy .

If T2 I usually do start with a CT neck with IV contrast; if anything fishy on the nodes I'll go then to PET. Of our 4 attendings that did head and neck, only 1 really ever used IMRT or treated nodes in this situation. It's been a few years since boards, but I think the "oral board" answer here is still opposed fields, preferably some sort of altered fractionation (65.25 Gy @2.25 or BID like the RTOG study or 6 fractions per week; some retrospective studies suggest an "average weekly dose" of at least 2 Gy is the "sweet spot" here, so just get there however you need to).

As an aside, I think IMRT here is perfectly fine here if anyone would do that (and I've done it on a young mid 30's patient, smoker, figured a long lifetime of carotid issues possibly), I just don't typically do that. I would use generous margins though and would probably consider the bilateral true vocal folds within my CTV. Really don't want to miss a target getting cute there, but I think the carotid sparing can be beneficial and achievable even with big margins.

 

[scarbrtj]

Treating with IMRT and specifically avoiding lymph node coverage wouldn't be normal either.

A wedge modulates the intensity of the beam, has "been in clinical use for the [past five decades]," and has been used in glottic CA radiotherapy rather normally
(As many probably know, there's a propensity in other parts of the world to avoid treating nodes in certain laryngeal CA situations where we in the US do; I reckon our "lymph node ideas" in the U.S. about H&N cancer are almost entirely Lindbergian.) There's now quite a bit of literature on "IMRT" for glottic CA. I'd like to think I was a bit of an early driver of the technique/rationale... maybe. If you eliminate $$$ concerns, and aren't offended by my hyperbole, non-IMRT treatment of glottic CA is a ridiculous alternative to IMRT tx.

 

[nkmiami]

The rational for carotid sparing is sound, but practically if you treat a lot of hypofractionated larynx, you will see that many pts have pretty severe skin break down that can be lessened with very simple IMRT plans that actually take less effort and resources with todays systems.

 

[evilbooyaa]

... I don't consider wedging IMRT. It may technically be, and to me that's semantics. I guess I have to be more specific - inverse planning or multi-field fixed IMRT is what I'm referencing. Things that you bill as 'IMRT'. Hopefully you're not billing 'I used wedges' as doing an IMRT plan.

Even if you're doing 5x5 box, you still do a CT Sim (in this day and age) and Wedge to decrease heterogeneity. You still should treat with 3D conformal technique. When I think IMRT I think VMAT, Tomo, and multiple field fixed beam angles.

 

[scarbrtj]

... I don't consider wedging IMRT. It may technically be, and to me that's semantics. I guess I have to be more specific - inverse planning or multi-field fixed IMRT is what I'm referencing. Things that you bill as 'IMRT'. Hopefully you're not billing 'I used wedges' as doing an IMRT plan.

Even if you're doing 5x5 box, you still do a CT Sim (in this day and age) and Wedge to decrease heterogeneity. You still should treat with 3D conformal technique. When I think IMRT I think VMAT, Tomo, and multiple field fixed beam angles.

I can perform a three-field, 3D plan using wedges and get a dose distribution with which I'm happy. The wedges, as they're electronic now instead of metallic/physical, are sliding MLCs moving across the field while the beam is on to provide an equivalent dose distribution to that of a old-style physical wedge. After much back-and-forth GUI fiddling, I can get a combination of wedges and beam angles to give me the dose I want. (I believe that in some centers they will actually even "QA" the sliding window electronic wedges in a manner like that of regular 'ol sliding window IMRT). I can also take the exact same three-field approach and specify in software that I want a highly homogenous fluence in the beam output, take a few seconds and do some optimization calcs and dose calcs, and "spit out" an almost identical plan in which if you were to eyeball the leaf motions between the "3D" and the "IMRT" plan... you couldn't tell which was which.

And yet one we call "3D" and one we call "IMRT," one we bill one way and one we bill another, one we embrace and one we throw shade upon; and all this unfortunately does usually lead to some discussion about "semantics."

 

[medgator]

.

And yet one we call "3D" and one we call "IMRT," one we bill one way and one we bill another, one we embrace and one we throw shade upon; and all this unfortunately does usually lead to some discussion about "semantics."

Well one component of imrt is the use of computer-optimized inverse planning for target and avoidance structures, something not seen when using wedges or FinF technique to reduce hot spots when forward planning a field or volume

 

[nkmiami]

inverse optimization is a billing requirement for imrt, but not technical. In fact, the British had a randomized trial titled "imrt" in breast with positive results- but, the treatment was what we call forawrd planned"field in a field"

 

[evilbooyaa]

I can perform a three-field, 3D plan using wedges and get a dose distribution with which I'm happy. The wedges, as they're electronic now instead of metallic/physical, are sliding MLCs moving across the field while the beam is on to provide an equivalent dose distribution to that of a old-style physical wedge. After much back-and-forth GUI fiddling, I can get a combination of wedges and beam angles to give me the dose I want. (I believe that in some centers they will actually even "QA" the sliding window electronic wedges in a manner like that of regular 'ol sliding window IMRT). I can also take the exact same three-field approach and specify in software that I want a highly homogenous fluence in the beam output, take a few seconds and do some optimization calcs and dose calcs, and "spit out" an almost identical plan in which if you were to eyeball the leaf motions between the "3D" and the "IMRT" plan... you couldn't tell which was which.

And yet one we call "3D" and one we call "IMRT," one we bill one way and one we bill another, one we embrace and one we throw shade upon; and all this unfortunately does usually lead to some discussion about "semantics."

3-fields can be called IMRT? I thought it required more than that, at least to bill. Would you bill what you described (the bolded) as IMRT? I guess IMRT at my institution is VMAT so not a realistic comparison.

 

[Brim]

I can perform a three-field, 3D plan using wedges and get a dose distribution with which I'm happy. The wedges, as they're electronic now instead of metallic/physical, are sliding MLCs moving across the field while the beam is on to provide an equivalent dose distribution to that of a old-style physical wedge. After much back-and-forth GUI fiddling, I can get a combination of wedges and beam angles to give me the dose I want. (I believe that in some centers they will actually even "QA" the sliding window electronic wedges in a manner like that of regular 'ol sliding window IMRT). I can also take the exact same three-field approach and specify in software that I want a highly homogenous fluence in the beam output, take a few seconds and do some optimization calcs and dose calcs, and "spit out" an almost identical plan in which if you were to eyeball the leaf motions between the "3D" and the "IMRT" plan... you couldn't tell which was which.

And yet one we call "3D" and one we call "IMRT," one we bill one way and one we bill another, one we embrace and one we throw shade upon; and all this unfortunately does usually lead to some discussion about "semantics."

But in the one we call "IMRT," the computer did a lot more work. The computer wants to bill correctly for all that optimization time. If you undercode the computer's work, you run the risk of making your computer disgruntled, and we all know how that can turn out.

 

[Gfunk6]

But in the one we call "IMRT," the computer did a lot more work. The computer wants to bill correctly for all that optimization time. If you undercode the computer's work, you run the risk of making your computer disgruntled, and we all know how that can turn out.

We are already to a bad start because we [humans] bill for all the computer's work and take all the money only to spend it on frivolous homo sapien expenses (e.g. food, shelter, utilities, super yachts).

 

[scarbrtj]

Well one component of imrt is the use of computer-optimized inverse planning for target and avoidance structures, something not seen when using wedges or FinF technique to reduce hot spots when forward planning a field or volume

Not true. Medicare/CMS says IMRT can be inverse or forward planned.

"(Dose plan is optimized using inverse or forward planning technique for modulated beam delivery (e.g., binary dynamic MLC) to create highly conformal dose distribution."

EDIT: this is or could be an outdated LCD for your region and it seems that just in the last year or two did the "mandate" for inverse opt come in. CMS is moving the science of IMRT forward... or is it backward/inverse? IDK.

 

[scarbrtj]

3-fields can be called IMRT? I thought it required more than that, at least to bill. Would you bill what you described (the bolded) as IMRT? I guess IMRT at my institution is VMAT so not a realistic comparison.

Yes (btw how many "fields" is VMAT?? ∞ or 1?? )

 

[evilbooyaa]

Yes (btw how many "fields" is VMAT?? ∞ or 1?? )

Hundreds and not something that can be done in reasonable time by a human being, IMO.

Cheekiness aside, I'm truly curious if people are billing that they placed 2 or 3 fields, did inverse planning (or not) and that is therefore IMRT.

What about FiF for breast? Is that being billed as IMRT?

 

[scarbrtj]

Hundreds and not something that can be done in reasonable time by a human being, IMO.

Cheekiness aside, I'm truly curious if people are billing that they placed 2 or 3 fields, did inverse planning (or not) and that is therefore IMRT.

What about FiF for breast? Is that being billed as IMRT?

IDK, I wouldn't think so now, but it prob was in the past, and correctly so. Although recent updates to LCDs make that past correct approach now incorrect. It's all pretty confusing--to be doing the right thing medically/scientifically, make sure you keep up to date with the CMS and insurance co. definitions. If you do inverse opt and IMRT QA, bill it as you see fit. It doesn't sound like that'd be 3D but I'm no billing expert. Just an IMRT expert.

 

[nkmiami]

Hundreds and not something that can be done in reasonable time by a human being, IMO.

Cheekiness aside, I'm truly curious if people are billing that they placed 2 or 3 fields, did inverse planning (or not) and that is therefore IMRT.

What about FiF for breast? Is that being billed as IMRT?

many of us dont share in the technical component, so no real incentive here, but I would be wary of billing FIF breast as IMRT

 

[medgator]

many of us dont share in the technical component, so no real incentive here, but I would be wary of billing FIF breast as IMRT

Agreed. I think electronic compensation would be a more legit charge there.

Bundled payments will solve this and other issues

 

[Haybrant]

quick question: I have an oropharynx BOT case T1N3 7 cm nodal conglomerate; when using IMRT in a situation like this do you have a strategy to keep the mean larynx dose to tolerance, what are you wiling to accept for variation? How often do you replan in this setting (P16 positive).

Also, mods is there some better way for us to aggregate questions through SDN. I don't want to hijack a thread but also starting a totally new thread sometimes seems like too much - its one of the most useful parts, asking case related questions imho

 

[Palex80]

quick question: I have an oropharynx BOT case T1N3 7 cm nodal conglomerate; when using IMRT in a situation like this do you have a strategy to keep the mean larynx dose to tolerance, what are you wiling to accept for variation? How often do you replan in this setting (P16 positive).

I presume you will be delivering simultaneous radiochemotherapy? In that case, remission can be fast and I would watch CBCT-scans to see for early changes and replan at around 30 Gy.
I don't pay that much attention to larynx when treating outside of it, but that's just me....

 

[evilbooyaa]

quick question: I have an oropharynx BOT case T1N3 7 cm nodal conglomerate; when using IMRT in a situation like this do you have a strategy to keep the mean larynx dose to tolerance, what are you wiling to accept for variation? How often do you replan in this setting (P16 positive).

Also, mods is there some better way for us to aggregate questions through SDN. I don't want to hijack a thread but also starting a totally new thread sometimes seems like too much - its one of the most useful parts, asking case related questions imho

I think your questions generally bring up interesting discussion Haybrant. I think it'd generally be better to create a new thread for them, but it's not a big deal IMO. It also helps posterity by allowing a thread to be focused on one thing. 'Totally new threads' IMO aren't really a big deal.

Given it's a small BoT primary and you're asking about larynx, I'm assuming the node at least extends to co-planar with Larynx, level III? Is there contralateral nodal disease that will have to be taken to 70Gy? We generally shoot for a mean larynx of 45 but that would likely be difficult (depending on anatomy) with 70Gy to one side, and elective dosing to the contralateral neck. Depending on distance of the node from larynx, and whether there is obvious ECE or not, you might be SOL and accepting mean larynx of 50 or 55. Crop your nodal CTV (if you create them) aggressively, and consider minimizing PTV expansion medially, especially if you can (or routinely) do daily cone beam.

Agree with Palex, A re-plan is very likely to be beneficial a few weeks into treatment. Depends on response obviously but somewhere in the 20-40Gy range. Will be important to minimize skin toxicity as well with a re-plan.

 

[Haybrant]

I think your questions generally bring up interesting discussion Haybrant. I think it'd generally be better to create a new thread for them, but it's not a big deal IMO. It also helps posterity by allowing a thread to be focused on one thing. 'Totally new threads' IMO aren't really a big deal.

Given it's a small BoT primary and you're asking about larynx, I'm assuming the node at least extends to co-planar with Larynx, level III? Is there contralateral nodal disease that will have to be taken to 70Gy? We generally shoot for a mean larynx of 45 but that would likely be difficult (depending on anatomy) with 70Gy to one side, and elective dosing to the contralateral neck. Depending on distance of the node from larynx, and whether there is obvious ECE or not, you might be SOL and accepting mean larynx of 50 or 55. Crop your nodal CTV (if you create them) aggressively, and consider minimizing PTV expansion medially, especially if you can (or routinely) do daily cone beam.

Agree with Palex, A re-plan is very likely to be beneficial a few weeks into treatment. Depends on response obviously but somewhere in the 20-40Gy range. Will be important to minimize skin toxicity as well with a re-plan.

thanks EvilB, this sounds good. Figured Id replan him and see if he responds fast, probably will cut down on the PTV margin a bit there too but ya the location of the node is the big issue here and the prox to the larynx.

Also, can you expand on your skin tox comment, is the issue that if they are shrinking rapidly the dose to the skin is getting too hot? What do you do if you have concerns based on exam for high skin toxicity in head and neck cases generally?

 

[evilbooyaa]

Also, can you expand on your skin tox comment, is the issue that if they are shrinking rapidly the dose to the skin is getting too hot? What do you do if you have concerns based on exam for high skin toxicity in head and neck cases generally?

If a big node, that is causing fullness, shrinks during treatment, it will likely pull the skin in (more medially). Your PTV70, covering the same 3-dimensional area, is now closer to the actual skin surface.

Similar to weight loss during H&N, but this is focal (rather than global) and affects local skin toxicity in the area of the lymph node. A re-plan can be the difference between erythema and moist desquamation requiring treatment breaks.

Kind of hard to describe without pictures or monitoring CBCTs, so let me know if that's not sufficient.

 

[nkmiami]

I assume it is HPV+ ?