What are the treatment options for glioma?

Hi, I would like to understand the treatment options for the most important types of brain tumors.
Specifically, what is the best treatment (both radiotherapy and chemotherapy) that we can offer patients with:

1. Well differentiated astrocytoma (grade II)
2. Anaplastic astrocytoma (grade III)
3. Glioblastoma multiforme (grade IV)
4. Low grade oligodendroglioma (grade II)
5. Anaplastic oligodendroglioma (grade III)

Also, how important is it to be able to differentiate between astrocytoma (grade II and III) and olilgodendroglioma (grade II and III)?
Does a differential diagnosis have any implications for the treatment of the patients?

I am asking because I am looking for relevant biomarkers for these brain tumors (such as the LOH 1p/19q for ODGs), and I would like to understand if there is any treatment benefit for the patient provided that we can separate e.g. oligodendrogliomas from astrocytomas at an early stage.

Thank you for any help that you may provide.

- Thomas

[rumpled]

Some of that can depend on the patient's prior health, as well as the location of the tumor.

Radiation has benefits, but it can damage surrounding tissues, but sometimes can be the only option in some cases.

Chemo is also good if there is one that they have that will treat the tumor the patient has - the doctors will know more - yet has a lot of side effects.

I think these questions are better suited for the doctor of the case - has he been asked? There is also a doctor forum here. Also, maybe someone here may have more expertise than I.