Uveal melanoma post enucleation

[Treat]

Dear colleagues,

I would appreciate your advice for this patient..

70 female, good performance status
Had enucleation for uveal melanoma - epithelioid, 18mm, 2mm thick, diffusely and widely invasive, optic nerve margin very close.

Referred for adjuvant RT - what dose, fractionation and modality would you recommend?

Thank you

---

Members don't see this ad.

 

[Palex80]

30-33 x 2 Gy. IMRT-photons.
At the end of the day, chiasm constraints are going to be your problem, depending on how close the positive margin was to the chiasm.

Protons could be beneficial, but I'd plan with IMRT-photons first.

 

[Treat]

Thanks Palex!

The surgeon left a long bit of optic nerve, so I'm not worried about the chiasm.

Was looking at NCCN - recommends 20(??)-30Gy in 5 fractions. Any concerns about hypofractionation? Higher than 30Gy?

 

[Soapcat]

I have done 48Gy in 20 fractions with VMAT, referring to Australian melanoma tx.
Mainly focused on contralateral eye and brain tissue sparing with this. Pt tolerated it very well.

 

[thecarbonionangle]

30-33 x 2 Gy. IMRT-photons.
At the end of the day, chiasm constraints are going to be your problem, depending on how close the positive margin was to the chiasm.

Protons could be beneficial, but I'd plan with IMRT-photons first.

I agree with this. Can hypofractionate as well. It is ok to plan with photons but this is an instance where protons will be fantastic. Send to a nearby proton centre if you can.

 

[Treat]

Thanks everyone for weighing in! Unfortunately, protons aren't an option..
Seems that the 5 X 6Gy from NCCN isn't too popular? Was considering that vs 6 X 6Gy since the chiasm is far enough away

 

[Palex80]

I'd like to push BED higher than 36/6 or 48/2.4, considering this is an R1-resection (provided there are no visible mets) for a durable local control.
This is a site you do not want to have to irradiate again down the road.
Hypofractionation is fine as well. 18 x 3 Gy maybe?

 

[ramsesthenice]

I agree with this. Can hypofractionate as well. It is ok to plan with photons but this is an instance where protons will be fantastic. Send to a nearby proton centre if you can.

Agreed. It sounds like the nerve margin is far enough removed from the chiasm that you actually will be able to meet tolerances with protons that you might not with photons. If it were too close to the chiasm I doubt they would buy you very much. It would look prettier, but I doubt it would be better in a meaningful way. But as described...there is a pretty high chance it will be superior more than just on paper. I bet you could still get a pretty good photon plan too (since it sounds like protons are not an option).

 

[Treat]

Yeah I agree protons would be great, but it's just not possible.

For melanoma, wouldn't 6 X 6Gy be somewhat equivalent to 18 X 3Gy?

 

[Palex80]

Yeah I agree protons would be great, but it's just not possible.

For melanoma, wouldn't 6 X 6Gy be somewhat equivalent to 18 X 3Gy?

Depending on the a/b you assume, I'd guess.

 

[Neuronix]

30/5 is often the dose for microscopic post-op disease based on MD Anderson and several papers by Ballo among others. I think boosting to 36/6 is reasonable for gross disease. I don't know of this data specifically for uveal melanoma but I feel like you can find a retrospective experience for just about anything.

I don't see what you'd hurt there other than skin at 30/5 (try to minimize the over 30 Gy dose) or mucosal surfaces assuming you can get chiasm, contralateral optical structures, and nearby temporal lobe down. Make sure the area is well healed before starting.

 

[gmsquid]

Thanks everyone for weighing in! Unfortunately, protons aren't an option..
Seems that the 5 X 6Gy from NCCN isn't too popular? Was considering that vs 6 X 6Gy since the chiasm is far enough

30/5 is often the dose for microscopic post-op disease based on MD Anderson and several papers by Ballo among others. I think boosting to 36/6 is reasonable for gross disease. I don't know of this data specifically for uveal melanoma but I feel like you can find a retrospective experience for just about anything.

I don't see what you'd hurt there other than skin at 30/5 (try to minimize the over 30 Gy dose) or mucosal surfaces assuming you can get chiasm, contralateral optical structures, and nearby temporal lobe down. Make sure the area is well healed before starting.

I agree with neuronix here. I do 30/5 for melanoma postoperatively all the time and would have no issue doing it in this location.