What OARs do you regularly contour for head and neck cases?

[PhotonBomb]

Interested in this. Feel like there’s likely a fair amount of variation

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[FrostyHammer]

I'm particularly interested in the people who are or are not constrictor contourers... Pros and cons either way.

 

[PhotonBomb]

I'm particularly interested in the people who are or are not constrictor contourers... Pros and cons either way.

I see zero cons to draw it

 

[radoncgrad2019]

In before SCARBTJ says ‘drawing doesn’t matter, pushing plans doesn’t matter, radiation doesn’t matter’

 

[deleted774703]

Oral Cavity
Lips
Constrictors
Larynx
Mandible
Submandibular Glands
Parotid Glands individual and combined
Cochlea
Cervical esophagus
Brachial Plexus
Spinal Cord
Brainstem
Optic Chiasm
Optic Nerves

 

[Radonky]

I'm particularly interested in the people who are or are not constrictor contourers... Pros and cons either way.

same

 

[gmsquid]

Always draw constrictors. You can essentially always spare at least a portion of them.

 

[RadOncDoc21]

Anybody local recurrences seen in sparing constrictors too much?

 

[deleted774703]

Anybody local recurrences seen in sparing constrictors too much?

no I’ve never seen that

Contour superior, inferior, and cricopharyngeus separately

Boolean together for constrictors sum

mean <50 for sum

based on location of primary, can spare at least 1 part of constrictors as mentioned above by @gmsquid

progressively lower mean for individual part of constrictors based on distance from primary

 

[radoncgrad2019]

Anybody local recurrences seen in sparing constrictors too much?

Not sure why you would. You’re not underdosing tumor, you’re underdosing normal structures.

I think compared to other disease sites, head and neck plans have the most variability between practices. Depends
On if you push the plans and draw tight versus people that essentially tried to turn 3D plans to IMRT and didn’t move much past that.

 

[gmsquid]

The risk of medial rp involvement for opx or npx cancer is nearly 0. Just make sure your isodoses are covering the ptv medially

 

[Palex80]

same

We do not. [****storm inbound]

 

[baculum1]

We do not. [****storm inbound]

same never have

 

[radoncgrad2019]

same never have

Time to start

 

[baculum1]

Time to start

we have more of a european approach as you can see

 

[radoncgrad2019]

we have more of a european approach as you can see

Some have a draw nothing approach. Maybe draw parotids and brainstem and cord and call it. Don’t be that guy

 

[deleted774703]

we have more of a european approach as you can see

You may want to reconsider since Europeans are the ones who made the OAR contouring guide in Green J and include constrictors

 

[RadOncDoc21]

I started doing them but don’t really restrict the coverage. Similar to my lung V5’s. Maybe I’ll start caring more these days. I use to do brachial plexus but realize if it’s between that and coverage, I choose coverage but rarely do I go over 66 max to them anyway... but still.

 

[radoncgrad2019]

I don’t draw plexus unless I’m treating gross disease (70) in the low neck.

 

[RadOncDoc21]

I don’t draw plexus unless I’m treating gross disease (70) in the low neck.

Would you lower dose to gross disease or high risk PTV to protect the BP?

 

[radoncgrad2019]

Would you lower dose to gross disease or high risk PTV to protect the BP?

No I would not compromise GTV but I might shave my PTV in some situations but I’m okay taking plexus to 70 if I have to

 

[gmsquid]

I started doing them but don’t really restrict the coverage. Similar to my lung V5’s. Maybe I’ll start caring more these days. I use to do brachial plexus but realize if it’s between that and coverage, I choose coverage but rarely do I go over 66 max to them anyway... but still.

I use these constraints when you have to go over 66: Dose--volume modeling of brachial plexus-associated neuropathy after radiation therapy for head-and-neck cancer: findings from a prospective screenin... - PubMed - NCBI

 

[dsh]

Contouring Consensus Document - American Society for Radiation Oncology (ASTRO) - American Society for Radiation Oncology (ASTRO)

Information and guidance on standardizing normal tissue contouring for radiation therapy treatment planning.

www.astro.org

 

[scarbrtj]

Oral Cavity
Lips
Constrictors
Larynx
Mandible
Submandibular Glands
Parotid Glands individual and combined
Cochlea
Cervical esophagus
Brachial Plexus
Spinal Cord
Brainstem
Optic Chiasm
Optic Nerves

Some have a draw nothing approach. Maybe draw parotids and brainstem and cord and call it. Don’t be that guy

I started doing them but don’t really restrict the coverage. Similar to my lung V5’s. Maybe I’ll start caring more these days. I use to do brachial plexus but realize if it’s between that and coverage, I choose coverage but rarely do I go over 66 max to them anyway... but still.

Some people are fascinated by the lips in IMRT. Maybe I should say worried about the lips, or scared of lip toxicity. Never seen it personally. (And... listing "lips" and "oral cavity" as separate items is redundant.) If one is worried about the optic chiasm in a H&N plan, wouldn't one also want to spare the pituitary (which probably has a lower tolerance than the chiasm). I think pituitary toxicity could affect a person maybe more than lip toxicity, who knows.

Contouring effort (Nancy Lee once said it takes her three hours to contour a NPC plan) doesn't correlate to many truly verified metrics. E.g., "At present, available evidence regarding the efficacy and safety of [submandibular gland]-sparing IMRT is extremely limited." And if you know a priori you're a prioritizer of tumor coverage vs piddly OAR sparing, the enthusiasm to turn a volumetric CT into a Netter's Atlas wanes. There's evidence for lots of things that may matter in HNSCC: giving cevimeline, making sure your patients are married, or the time of day you treat, or maybe even amifostine. There's more evidence for all the aforementioned vs contouring the {ORAL CAVITY{lips}}, or the SMGs.

 

[Mandelin Rain]

I knew the Lip contour commentary was coming. Thought it this morning, as I contoured Lips. Oral tongue thing coming pretty far anterior. Not sparing much oral cavity, so Lips it was.

 

[scarbrtj]

I knew the Lip contour commentary was coming. Thought it this morning, as I contoured Lips. Oral tongue thing coming pretty far anterior. Not sparing much oral cavity, so Lips it was.

Make sure you spare the optic chiasm too. And the lenses. And the rectum.

 

[PhotonBomb]

not sure why you wouldn't avoid the lips if you can. doesn't matter in many cases, but in an anterior oral cavity case, it def does, so I agree with M. Rain

I don't think some people get it. if you don't draw it as something, the planning system has no way of knowing the lip from random fat. If you draw it and tell computer to try and avoid it, it will. why give someone acute chelitis during RT if you don't have to?

Drawing pituitary is pointless IMO in many cases because it is certainly more radiation sensitive than something like the chiasm, and no matter what will be getting moderate-low doses of radiation in most cases, and so thus will impact long term pituitary function no matter what. Whereas the optic structures are vitally important, are correlated with max dose, and which if you don't draw, you cant make sure to avoid.

the pituitary vs optic structures comment might be one of the most truly ignorant things I've ever seen posted on this forum.

 

[PhotonBomb]

Make sure you spare the optic chiasm too. And the lenses. And the rectum.

you are making yourself look foolish.

if you are close to the optic structures (nasopharynx, oropharynx creeping up, you better know what it is getting.

 

[radoncgrad2019]

In before SCARBTJ says ‘drawing doesn’t matter, pushing plans doesn’t matter, radiation doesn’t matter’

called it.

 

[Mandelin Rain]

The Lips thing is a bit of a meme with Scar. Usually, I put in an oral cavity structure as an avoidance. The lips sit anterior to the OC, so they'll be spared as the computer tries to avoid the OC. But yes, I will contour lips if target volume comes into the OC itself for the reasons stated. The most efficient route to the tongue is AP unless you tell it not to.

Maybe I could (should?) be optimizing IMRT plans on Saturdays....

 

[scarbrtj]

I don't think some people get it. if you don't draw it as something, the planning system has no way of knowing the lip from random fat. If you draw it and tell computer to try and avoid it, it will. why give someone acute chelitis during RT if you don't have to?

Oh I get it. One time I was submitting plans for an upper torso sarcoma case to a reviewer. I had personally done the (IMRT) plan; I personally do a lot of my own complex plans from A to Y (dosim does the Z). He was like,"I see you didn't contour the humeral head here." And I was like, "Yeah, but as you can tell when you look through the slices it's getting almost no dose." In the beam arrangements, I had done field-on-field overlaps with asym fixed jaws to completely spare the humerus, forcing the algorithm to do what I wanted. (An approach like this is infeasible ~99% of time in H&N, but I'm using this as analogy.) And he was like, "Yes but I still would contour the humeral head." If you make your dose fall-offs very conformal, the need to contour something like the lips goes down; totally diff situation if you have oral tongue SCC of course (and I would never spare SMGs in oral tongue e.g.). After first optimization, if you see a problem, you fix it. If there is no problem, there is no need to contour something which you can see with your own eyes/experience sits OK. Two ways to skin a cat, and if cat comes pre-skinned this is a timesaver.

 

[radoncgrad2019]

'If you make your dose fall-offs very conformal, the need to contour something like the lips goes down'

I agree with you about this for the most part, except that IN Head and Neck, I think you gain something by NOT making your dose-fall offs uniformally conformal around the PTV and specifically avoiding some things (named important structures) more than others (random muscles/fat). that is why I (and many others) draw more structures in the head and neck, and specifically ask planners (aka the computer) to avoid.

 

[scarbrtj]

'If you make your dose fall-offs very conformal, the need to contour something like the lips goes down'

I agree with you about this for the most part, except that IN Head and Neck, I think you gain something by NOT making your dose-fall offs uniformally conformal around the PTV and specifically avoiding some things (named important structures) more than others (random muscles/fat). that is why I (and many others) draw more structures in the head and neck, and specifically ask planners (aka the computer) to avoid.

I also agree and would say this is why I loathe dogma or a "don't be that guy" viewpoint in these very nuanced/"but what if" discussions. If I were part of a huge, incredibly busy focused H&N practice and dumping all my patients into a planning black box, I would undoubtedly take a very anal retentive approach on contouring. As is now, and has been most of my career, I can afford to take a very anal retentive approach to optimization/planning as well, doing a lot of the contouring "in my head" (the ultimate virtual contour: it's so virtual you might think I'm not contouring). (And there is as you mention a limit to conformality in HNSCC.) It is not wrong to contour lips, etc., in HNSCC IMRT. It's also not not wrong. Just like the lips are a part of the oral cavity, both are part of the BODY structure. This can be a powerful optimization tool, too; underutilized IMHO and can realllllly force the 50% isovol down. Which forces the 55% isovol down... which forces the 60% isovol down...

 

[scarbrtj]

you are making yourself look foolish.

if you are close to the optic structures (nasopharynx, oropharynx creeping up, you better know what it is getting.

Can one know what a structure (chiasm e.g.) is "getting" without contouring it as in the case of "oropharynx creeping up"... NPC is sui generis.

 

[scarbrtj]

The Lips thing is a bit of a meme with Scar. Usually, I put in an oral cavity structure as an avoidance. The lips sit anterior to the OC, so they'll be spared as the computer tries to avoid the OC. But yes, I will contour lips if target volume comes into the OC itself for the reasons stated. The most efficient route to the tongue is AP unless you tell it not to.

Maybe I could (should?) be optimizing IMRT plans on Saturdays....

This would also be an efficient route to the tongue, not anterior but couch 90/gantry 315 (can maybe push to 310)... has lip avoiding properties that non-off-axis doesn't...

 

[Mandelin Rain]

This would also be an efficient route to the tongue, not anterior but couch 90/gantry 315 (can maybe push to 310)... has lip avoiding properties that non-off-axis doesn't...

I would definitely contour the pituitary, if I were you.

 

[scarbrtj]

the pituitary vs optic structures comment might be one of the most truly ignorant things I've ever seen posted on this forum.

Thank you but really just skimming ignorance's surface here.

 

[KHE88]

We never really paid much attention to the lips in residency. My first oral cavity case out of residency, the patient experienced really bad mucositis on the inside of the lips. I try to get lips under 40, but I think it was 45 in this case. I put some wax in between the front teeth and the lips, and she healed up and sailed through the rest of treatment.

So I would not ignore the lips completely.

 

[nkmiami]

This would also be an efficient route to the tongue, not anterior but couch 90/gantry 315 (can maybe push to 310)... has lip avoiding properties that non-off-axis doesn't...

pt on treatment right now with that beam for FOM. most of radiation being delivered with coplanar vmat so negligible dose to superior structures.

 

[PhotonBomb]

Can one know what a structure (chiasm e.g.) is "getting" without contouring it as in the case of "oropharynx creeping up"... NPC is sui generis.

Thanks for the reply.

One question - are you a step and shoot guy for HN rather than VMAT?

 

[deleted774703]

I realize lips are part of oral cavity, but lips are more sensitive so I use difft constraints

I use mean <20 for lips and <30 for oral cavity

 

[baculum1]

Any of you guys routinely treating your head and necks 6 days a week or one BID day for 6 fx/week?

 

[scarbrtj]

Thanks for the reply.

One question - are you a step and shoot guy for HN rather than VMAT?

There is the third option, dMLC; VMAT is kind of a variant of that, but there has actually been step-and-shoot VMAT (which was the first commercially available IMRT system, the NOMOS MiMIC: step-and-shoot ~2-7 segment fields at ~5-10 degree intervals around the patient, and NOMOS heralded the MiMIC as a H&N breakthrough treatment). Step and shoot is inefficient time-wise, and not as (practically) capable of as "high resolution" fluence as dMLC. A dMLC field can be mathematically devolved into dosimetrically equivalent step-and-shoot's; again, due to time and depending on the dMLC fluence heterogeneity, it's not practical to implement that. Beyond that step and shoot is often times not even a tx option (due to lack of physics commissioning for it in the TPS) nowadays I've found in most centers. I do not like VMAT for full initial ENI+gross coverage (e.g. it's awkward to do shoulder avoidance with VMAT, it's easier with static beams and couch kicks). I like VMAT for the final boost portions of tx.

 

[Mandelin Rain]

I trained as a sequential boost person but went to dose painting, in large part due to inertia of the department I joined.

 

[BobbyHeenan]

Any of you guys routinely treating your head and necks 6 days a week or one BID day for 6 fx/week?

For the rare node + or T3 case that doesnt get chemo I give 70/56 with BID on fridays.

If concurrent I just do standard 5 fractions/week.

 

[seper]

I do for non-chemo patients (bid once per week).

Any of you guys routinely treating your head and necks 6 days a week or one BID day for 6 fx/week?

 

[radoncgrad2019]

agree, I do DAHANCA style for non-chemo patients.

 

[evilbooyaa]

Oral Cavity
Lips
Constrictors
Larynx
Mandible
Submandibular Glands
Parotid Glands individual and combined
Cochlea
Cervical esophagus
Brachial Plexus
Spinal Cord
Brainstem
Optic Chiasm
Optic Nerves

Spot on.

I prefer drawing constrictors individually. Differential sparing for a NPX vs OPX vs HypoPX primary for example.

Usually only draw Plexus if something > 60Gy is going to be in that area.