Salvage radiation for low grade glioma

[Gfunk6]

I've been following a middle-aged female for about 2 years with a large, diffuse, unresectable grade II oligodendroglioma (1p19q non co-deleted). Initial presenting symptoms were partial seizures. She was placed on anti-epileptics and temozolomide. After one year of chemo, no change in tumor on imaging so temozolomide was discontinued.

Now one year later she presented with breakthrough seizures and diplopia. These symptoms were mostly resolved with Decadron and a second anti-epileptic. Tumor board is now recommending salvage radiation. The treatment volumes are too damn big to seriously consider anything other than opposed tangents or a simple 3D plan.

The question is how high I should go in dose? Right now I'm thinking about 50.4 Gy in 28 fractions but am concerned about giving this much radiation to the entire supratentorial area. Unfortunately, there is no clear area to boost and none of the tumor is enhancing. I've prescribed her Namenda to preserve what I can of her future neuro-cognitive function.

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[medgator]

Sounds good. 50.4 gy was the dose in wbrt studies with and without surgery back in the day

 

[ramsesthenice]

Agreed. Im my training I have seen at least a few 3 field plans which basically treat the whole supratentorum to 50.4 Gy. Is there any chance their medical oncologist would consider PCV after radiation? It seems like not a lot of people are on board yet, but the mature 9802 data looks pretty good.

 

[BraggPeak]

Would you consider doing another biopsy to see if it has transformed into a HGG? Is this a non- enhancing lgg? Also, just curious what the rationale for chemo alone in this non-1p19q co deleted patient was?

 

[RadOncDoc21]

Would you consider doing another biopsy to see if it has transformed into a HGG? Is this a non- enhancing lgg? Also, just curious what the rationale for chemo alone in this non-1p19q co deleted patient was?

Accelerated repopulation and to select out the most resistant disease. Maybe because the patient was still alive... Who knows why everybody gets chemo, yet radiation is to blame for everything. I'm assuming it was to get her into surgery.