Recurrent atypical mengioma

[Palex80]

Interesting case today.

55 year old patient, s/p complete resection of a 4 cm atypical meningeoma 6 years ago (Simpson II).
No adjuvant treatment.

Presents now with a recurrent tumor, about 4mm in size, more or less in the middle of the initial tumor region (apparently some dura was left behind). No symptoms.

Would you treat only the recurrent tumor (SRS/FSRT) or the initial extension?
I would have treated only the recurrent tumor, especially given the long interval since surgery, but it's an atypical one. Thoughts?

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[BobbyHeenan]

That long of a relapse time I'd favor just treating the gross disease with radiosurgery. I struggle with these cases too, especially early-ish relpases where I'm questioning should I cover the cavity too, and if the cavity is small should I do single or 3-5 fraction radiosurgery or add more margin and give fractionated treatment (if no brain invasion I typically don't add much if any margin). But 4 years out, I'd just treat what you can see.

Now dosing is another question, but if fractionating I'd prefer the higher end of NCCN dosing (30 Gy in 5) but at just 4mm in size I'd probably do single fraction on the gamma knife, maybe 16-18 Gy (rather than say 14 Gy for a slower grower/grade 1).

 

[TheWallnerus]

Interesting case today.

55 year old patient, s/p complete resection of a 4 cm atypical meningeoma 6 years ago (Simpson II).
No adjuvant treatment.

Presents now with a recurrent tumor, about 4mm in size, more or less in the middle of the initial tumor region (apparently some dura was left behind). No symptoms.

Would you treat only the recurrent tumor (SRS/FSRT) or the initial extension?
I would have treated only the recurrent tumor, especially given the long interval since surgery, but it's an atypical one. Thoughts?

4mm recurrence? In 6 years it’s grown 4mm? Might we wait 6 more years to treat an 8mm meningioma?

 

[Palex80]

4mm recurrence? In 6 years it’s grown 4mm? Might we wait 6 more years to treat an 8mm meningioma?

Well, to be fair nothing grew in almost 5 years. Tumor popped up last year and now grew on 2 consecutive repeat MRIs. I presume it simply had to find someway to feed itself and is now growing, slowly.
But yes, one can surely wait and treat this down the road without compromising efficacy or risking substantial more morbidity.

 

[TheWallnerus]

Well, to be fair nothing grew in almost 5 years. Tumor popped up last year and now grew on 2 consecutive repeat MRIs. I presume it simply had to find someway to feed itself and is now growing, slowly.
But yes, one can surely wait and treat this down the road without compromising efficacy or risking substantial more morbidity.

I would favor a bit more observation. You’re thinking of treating a ~4cm tumor bed versus a 4mm recurrence at the present time. The former is roughly 500 times the volume of the latter. I would much prefer irradiating the latter, especially if it were my brain and I were relatively young. Maybe with more observation you’ll see ditzels arise in the ~4cm bed, or not, helping you make a very consequential treatment (volume) decision more intelligently. Not sure we need b*lls to wall typical rad onc cancer mindset here (which would be: we always need subclinical doses to a resected tumor bed).

 

[BobbyHeenan]

I don't think close observation is wrong, but I'd vote treat now.

Risk of necrosis /adverse events goes up the bigger this thing gets. You're going to be treating it eventually in a 50 year old. It will never be smaller than today and I would guess (wild ass guess) growth rate not linear in an atypical. And even if another nodule pops up later less likely to have overlapping doses if you're just treating 4mm now. And another nodule can be monitored too.

I'm biased because in this data-free zone but I have a few I've watched that ended up exploding ...though those were mostly lost to follow up with greater than or equal to 1 year gaps in between scans. So if observing I'd put on a 4 month follow up rather than a year.

Definitely would not be covering operative bed here though.

 

[Palex80]

And even if another nodule pops up later less likely to have overlapping doses if you're just treating 4mm now.

Can I treat only 4mm now? This is not Grade 1. I would need a CTV-margin.

 

[TheWallnerus]

Can I treat only 4mm now? This is not Grade 1. I would need a CTV-margin.

A picture tells a thousand words. Let’s see the scans!

 

[BobbyHeenan]

Can I treat only 4mm now? This is not Grade 1. I would need a CTV-margin.

Do you for sure? Was there brain invasion on the initial path?

Would need to see images. ...you could chase some meningeal area but it no initial brain invasion andonly 4mm 5 years later, I would be tempted to just treat what you see.

*ducks head as CNS purists shout me down*

 

[Neuronix]

Interesting case today.

55 year old patient, s/p complete resection of a 4 cm atypical meningeoma 6 years ago (Simpson II).
No adjuvant treatment.

Presents now with a recurrent tumor, about 4mm in size, more or less in the middle of the initial tumor region (apparently some dura was left behind). No symptoms.

Would you treat only the recurrent tumor (SRS/FSRT) or the initial extension?
I would have treated only the recurrent tumor, especially given the long interval since surgery, but it's an atypical one. Thoughts?

30 fractions
60 Gy to current disease plus 5 mm CTV
54 Gy to entire cavity plus 5 mm CTV

Crop both CTVs off brain if no brain invasion on path. I also tend to edit off skull if it didn't really invade skull.

I personally like to do fractionated first to a large field in recurrent atypical because I get a lot of multifocal recurrences in my clinic that I like to think I can prevent by doing it this way.

Not wrong to do SRS. There is data for both approaches in recurrent atypical. If doing SRS, I like to blast these, personally would do at least 18 Gy. Something that tiny I'd probably do 20 or low 20s because I can and atypicals have high rate of local failure, especially with gross disease. Pew pew. We're working on an article on this to see if I'm right.

 

[TheWallnerus]

30 fractions
60 Gy to current disease plus 5 mm CTV
54 Gy to entire cavity plus 5 mm CTV

Crop both CTVs off brain if no brain invasion on path. I also tend to edit off skull if it didn't really invade skull.

I personally like to do fractionated first to a large field in recurrent atypical because I get a lot of multifocal recurrences in my clinic that I like to think I can prevent by doing it this way.

Not wrong to do SRS. There is data for both approaches in recurrent atypical. If doing SRS, I like to blast these, personally would do at least 18 Gy. Something that tiny I'd probably do 20 or low 20s because I can and atypicals have high rate of local failure, especially with gross disease. Pew pew. We're working on an article on this to see if I'm right.

Don’t you think a multi focal recurrence here is a little less likely at 6 years out. How about 7 years out. How about ten

I don’t do this often, but if I were the patient I would make you guys do a few more 4 or 6 month serial MRIs. I love thinking deep and complicated thoughts, it’s one of my favorite hobbies, and I think RT to a 4cm cavity in my 50s might hinder my hobby a little bit in my 60s.

 

[Mandelin Rain]

I've seen some very aggressive late atypical recurrences. I would treat a bigger field.

 

[BobbyHeenan]

Don’t you think a multi focal recurrence here is a little less likely at 6 years out. How about 7 years out. How about ten

I don’t do this often, but if I were the patient I would make you guys do a few more 4 or 6 month serial MRIs. I love thinking deep and complicated thoughts, it’s one of my favorite hobbies, and I think RT to a 4cm cavity in my 50s might hinder my hobby a little bit in my 60s.

Yeah I'm not dogmatic on this case, but if it's me I'm taking SRS and frequent scans.

Though I probably would have signed up for wider field adjuvant from the get go. But at 6 years out i'm rolling the dice.

LIke Neuronix said though..."not wrong." If my partner showed this case at new patient conference with 60 Gy over 6 weeks I'd put my head down and move on to next one. It's a "gut feeling"style thing here. Crop out the brain (if no invasion) and beam on if that's what you feel is best.

 

[BobbyHeenan]

Sorry Palex, we're not helping your case here

 

[Palex80]

Sorry Palex, we're not helping your case here

You are! There was also a very controversial discussion in the clinic!

 

[evilbooyaa]

I am wary that if a patient has recurred in one part of the field at 6 years, whether they will recur in a different part of the field at a later time point.

So, despite the time interval, I agree with Neuronix. I personally think SRS for atypical meningioma is penny wise, pound foolish. I'd be more in-line with observing if desired.

 

[yesmaster]

Additional path details may be helpful. WHO grading has changed and atypical meningiomas used to be more aggressive, with brain invasion, high mitotic index, etc.

Personally with the long disease free interval, I would do SRS. Like BNI circa 2013.

The impact of adjuvant stereotactic radiosurgery on atypical meningioma recurrence following aggressive microsurgical resection - PubMed

Atypical meningiomas are increasingly irradiated, even after complete or near-complete microsurgical resection. This analysis of the largest patient series to date suggests that close observation remains reasonable in the setting of aggressive microsurgical resection. Although postoperative...

pubmed.ncbi.nlm.nih.gov

 

[Palex80]

Additional path details may be helpful. WHO grading has changed and atypical meningiomas used to be more aggressive, with brain invasion, high mitotic index, etc

mitosis rate: 10%, 4/10 HPF
brain invasion "possible but not proven".

The pathologists do not that no signs of anaplasia were seen and that the grade 2 classification is based on the increased mitosis rate.

A methylation analysis also classified it as grade 2.

 

[grenz]

Anyone getting DOTATATE or C11 PETs for treatment planning of meningiomas? See RT treatment planning section below

PET imaging in patients with meningioma—report of the RANO/PET Group

Abstract. Meningiomas are the most frequent nonglial primary brain tumors and represent about 30% of brain tumors. Usually, diagnosis and treatment plannin

academic.oup.com

 

[Palex80]

Anyone getting DOTATATE or C11 PETs for treatment planning of meningiomas? See RT treatment planning section below

PET imaging in patients with meningioma—report of the RANO/PET Group

Abstract. Meningiomas are the most frequent nonglial primary brain tumors and represent about 30% of brain tumors. Usually, diagnosis and treatment plannin

academic.oup.com

I've done it only a few times. DOTATATE. Does require something like "prior authorization" though.

 

[Neuronix]

Anyone getting DOTATATE or C11 PETs for treatment planning of meningiomas? See RT treatment planning section below

I do a DOTATATE PET when the MRI is unclear (a lot of thickened non specific dura or sometimes at skull base/cavernous sinus where there's a lot of enhancement anyway) or they have multifocal high grade or grade 3 disease to rule out spinal or systemic dissemination.

mitosis rate: 10%, 4/10 HPF
brain invasion "possible but not proven".

The pathologists do not that no signs of anaplasia were seen and that the grade 2 classification is based on the increased mitosis rate.

A methylation analysis also classified it as grade 2.

I wouldn't treat this one into brain. PTV still covers brain surface. Failure pattern is almost exclusively along dura.

I never can figure out what to do with MIB-1/Ki-67. Apparently it's too variable across institutions. 4/10 HPF is also barely atypical. Neuro-oncology often sends NGS but it rarely adds anything, and in a case this benign looking I think finding TERT promoter mutation or CKN2A/B homozygous deletion is unlikely.

I'm talking myself into SRS more with this discussion. These controversies can be a good thing to discuss with the patient, as sometimes they'll have an opinion one way or the other. For example, in my clinic they'll often specifically ask for proton, and of course that's going to be conventionally fractionated.

 

[evilbooyaa]

Really interesting concepts at play here....

Some people think this might not suitable for SRS.... or want to 'talk themselves' into SRS. When we know fractionated works as well and is agnostic to all of the other concerns people have about SRS. In terms of toxicity, it's a meningioma - they're going to be fine with small PTV margins.

The push to drop fractions affecting SDN now?

 

[Neuronix]

Really interesting concepts at play here....

Some people think this might not suitable for SRS.... or want to 'talk themselves' into SRS. When we know fractionated works as well and is agnostic to all of the other concerns people have about SRS. In terms of toxicity, it's a meningioma - they're going to be fine with small PTV margins.

The push to drop fractions affecting SDN now?

Some patients really struggle with coming in for 6 weeks of RT, especially when there's a single fraction option.

To my mind this isn't a hypofrac issue, it's more a what's appropriate for radiosurgery issue. A lot of the neurosurgeons I've worked with would want to SRS this for sure.

 

[temujim]

Some patients really struggle with coming in for 6 weeks of RT, especially when there's a single fraction option.

To my mind this isn't a hypofrac issue, it's more a what's appropriate for radiosurgery issue. A lot of the neurosurgeons I've worked with would want to SRS this for sure.

Really can't bring myself to care what a neurosurgeon thinks about any form of radiotherapy.

 

[Neuronix]

Really can't bring myself to care what a neurosurgeon thinks about any form of radiotherapy.

They invented both cyber knife and gamma knife, so I give them credit when it's due.

 

[temujim]

They invented both cyber knife and gamma knife, so I give them credit when it's due.

No one remembers borje larsson. Sad!

adler invented the linear accelerator AND the robotic arm?

Still don't care what they think about radiation treatment of day to day patients.

 

[RickyScott]

They invented both cyber knife and gamma knife, so I give them credit when it's due.

didnt neurosurg invent commercial imrt? pretty sure they did with the nomos peacock system. Astro gave the guy a sticker or something for making the biggest modern contribution ever to our specialty. i dont know his name and I am sure most residents dont know "the father of imrt"

edit: here: Neurosurgeon Mark P. Carol Honored by ASTRO For Contributions to IMRT, IGRT

The take home message is that our most important technologies were created by outside specialists since the boomers in this field are a damaged collection of losers who could never come up with something like this. Now those same losers are wrecking the specialty.

 

[sirspamalot]

Peacock! Oh man, I remember that thing. I had absolutely NO IDEA how it worked, and the faculty person working on it couldn't explain it to me either. And yet, publish papers we did.

I still think the whole "moving gantry arm and moving leaves, simultaneously" is magic.