IMRT for T1N0 TVC

[Ray D. Ayshun]

Is anyone doing this? In my readings I've seen this mentioned as a thing. I can see it working just as well as opposed laterals/3 field, and may be able to better spare carotid arteries. OTOH, I'm not convinced it's a worthwhile gain. Happy to be convinced otherwise.

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[Palex80]

Is anyone doing this? In my readings I've seen this mentioned as a thing. I can see it working just as well as opposed laterals/3 field, and may be able to better spare carotid arteries. OTOH, I'm not convinced it's a worthwhile gain. Happy to be convinced otherwise.

We are doing it.

It does have some benefits, but alot depends on the location of the lesion. Just like you said, we primarily try to focus on sparing carotids and the contralateral cord (when lateralized tumor), especially the arytenoid cartilage.

You need a compliant patient and some education, so that no swallowing takes place. We use a camera to check that.

 

[OTN]

I've done it- sparing of carotids as mentioned and, depending on whether neck has to be bolused or not (if ant comm tumor), improvement in skin toxicity. I demaned 100% coverage of the PTV.

 

[scarbrtj]

Is anyone doing this? In my readings I've seen this mentioned as a thing. I can see it working just as well as opposed laterals/3 field, and may be able to better spare carotid arteries. OTOH, I'm not convinced it's a worthwhile gain. Happy to be convinced otherwise.

“3 field” is IMRT IMHO. Did I invent this technique... it’s clouded in the mists of time.

SIMPLE CAROTID-SPARING INTENSITY-MODULATED RADIOTHERAPY TECHNIQUE AND PRELIMINARY EXPERIENCE FOR T1–2 GLOTTIC CANCER

To investigate the dosimetry and feasibility of carotid-sparing intensity-modulated radiotherapy (IMRT) for early glottic cancer and to report preliminary clinical experience.Digital Imaging and Communications in Medicine radiotherapy (DICOM-RT) datasets ...

www.ncbi.nlm.nih.gov

 

[evilbooyaa]

Not routinely - the last one T1N0 larynx cancer pt I had, I thought about it, but the patient was already 70 without CAD. If I had a 50s year old that had a long development period for carotid atherosclerosis, or somebody with predisposing risk factors for carotid atherosclerosis/stroke I'd have more strongly considered IMRT. I won't begrudge those who consider it routine for every case, however. I just don't think we have any actual proven benefit to carotid sparing, and I'd like to see the data before I make it a routine aspect of clinical practice.

But if I was to do IMRT, I'd still treat the entirety of the larynx to Rx dose. I'm not sure if single cord irradiation is ready for primetime, and don't really want to be an early adopter on something that I don't really know whether it is oncologically safe, especially for something that has such excellent control and minimal toxicity already, where the salvage option is likely a total laryngectomy if not caught super early.

 

[medgator]

.

But if I was to do IMRT, I'd still treat the entirety of the larynx to Rx dose. I'm not sure if single cord irradiation is ready for primetime, and don't really want to be an early adopter on something that I don't really know whether it is oncologically safe, especially for something that has such excellent control and minimal toxicity already, where the salvage option is likely a total laryngectomy if not caught super early.

Pretty much what i do in node+ larynx anyways

 

[scarbrtj]

Not routinely - the last one T1N0 larynx cancer pt I had, I thought about it, but the patient was already 70 without CAD. If I had a 50s year old that had a long development period for carotid atherosclerosis, or somebody with predisposing risk factors for carotid atherosclerosis/stroke I'd have more strongly considered IMRT. I won't begrudge those who consider it routine for every case, however. I just don't think we have any actual proven benefit to carotid sparing, and I'd like to see the data before I make it a routine aspect of clinical practice.

But if I was to do IMRT, I'd still treat the entirety of the larynx to Rx dose. I'm not sure if single cord irradiation is ready for primetime, and don't really want to be an early adopter on something that I don't really know whether it is oncologically safe, especially for something that has such excellent control and minimal toxicity already, where the salvage option is likely a total laryngectomy if not caught super early.

Less skin toxicity w/3 field vs 2 field. Whether the 3 has “gotta” be IMRT is doctor’s choice. (But a lot quicker, more efficient plan can be ran w/inv optimization vs iterative human optimizing.) You know where this convo is going!

 

[evilbooyaa]

Less skin toxicity w/3 field vs 2 field. Whether the 3 has “gotta” be IMRT is doctor’s choice. (But a lot quicker, more efficient plan can be ran w/inv optimization vs iterative human optimizing.) You know where this convo is going!

 

[Ray D. Ayshun]

Re treating a single cord, I saw mention of an sib. Whole larynx gets 50 something and half gets 66-70. Something like that. I use 2.25 Gy fx anyway, but saw that mentioned. In any case, good to know people are doing it and why. I will say, when I saw IMRT in the titles of some of these, I just read the abstract, and didn't look deeply enough to see they're talking 3 field IMRT. I was thinking infinite field. In any case, 3 field IMRT makes a little more sense. Thanks for the paper.

 

[RickyScott]

I often use it for sib, and sparing carotid and contra lateral (in localized cases) arytenoid a little bit. You also don’t get a skin rxn like with opposed laterals. So little effort, not sure why it isn’t used more frequently.

 

[scarbrtj]

There’s some old UF paper somewhere where they were doing 3 field and wedging and weighting to “favor” one vocal cord. There’s nothing too new about that.

 

[gmsquid]

I always do it. Under appreciated benefit is that you reduce lymphedema and in patients with large necks which run hot with 3D, you may spare them significant lymphedema which could lead to tracheostomy.

 

[evilbooyaa]

I always do it. Under appreciated benefit is that you reduce lymphedema and in patients with large necks which run hot with 3D, you may spare them significant lymphedema which could lead to tracheostomy.

Really? Lymphedema so severe requiring trach? Is that a serious concern? Is that published anywhere or is this just a 'I saw this one time in my life' anecdote?

 

[medgator]

Really? Lymphedema so severe requiring trach? Is that a serious concern? Is that published anywhere or is this just a 'I saw this one time in my life' anecdote?

Honestly how many people have seen their glottic pts treated with POP (parallel opposed portals) get a trach for post radiation neck edema?

0, personally

 

[Ray D. Ayshun]

I read about this once on SDN is a new indication for IMRT, personally.

 

[kimplera]

All our T1N0 larynx are treated with 4 fields. simple, partly spares carotid without modulation - no pushback from insurance

 

[RickyScott]

All our T1N0 larynx are treated with 4 fields. simple, partly spares carotid without modulation - no pushback from insurance

I have used 4 field diamond approach, but the imrt is marginally better, especially if you want to spare contra lateral arytenoid a little bit. Don’t feel bad about it because our hospitals negotiated prices are very close to cms rates.

 

[seper]

AFAIK, no data to support carotid sparing. Stroke incidence is not elevated.
IMRT can be trickier to salvage.

 

[FrostyHammer]

AFAIK, no data to support carotid sparing. Stroke incidence is not elevated.
IMRT can be trickier to salvage.

Great point... Can anyone share why carotid sparing is even a concept in this condition? If it's because they live long, then consider that it's hard to do anything about it in HPV+ OPSCC...

 

[scarbrtj]

Great point... Can anyone share why carotid sparing is even a concept in this condition? If it's because they live long, then consider that it's hard to do anything about it in HPV+ OPSCC...

There’s enough data to establish it as a concept. If I ever get a HN Ca and my carotids can be spared via a simple switch of RT technique, I’d definitely love to have it (if my insurance company will pay for it). And I would like to have less skin burns vs 2 field.

 

[Palex80]

Carotid sparing when treating lymphatics is not feasible, not the same scenario as in early larynx cancer were the carotids are not in the PTV.

 

[dieABRdie]

I just had a patient finish IMRT for T1b Larynx. He looked like this:

 

[scarbrtj]

I just had a patient finish IMRT for T1b Larynx. He looked like this:

View attachment 327929

Neat.

 

[Grubbe-a-dub-dub]

I did carotid sparing IMRT for a T1 case who had bilateral CEAs for stenosis. The wife was justifiably concerned about the carotids so I did it - it pays big time to have a smart spouse. He also had a stocky neck like that picture so it was a much easier set-up and delivery.

No issue with insurance approval - although I'm sure the second evicore sees thread this it will no longer be medically necessary.

AAAAND it's gone.