Initial treatment of IDH-mutant, 1p/19q-codeleted oligodendroglioma (grade 2 and 3) in adults

IDH: isocitrate dehydrogenase; MRI: magnetic resonance imaging; WHO: World Health Organization; RT: radiation therapy; PCV: procarbazine, lomustine, vincristine.

* Modest amounts of residual grade 2 tumor after surgery, even measuring >1 to 2 cm, may be reasonably observed in some cases, provided that the patient is asymptomatic from the tumor aside from well-controlled epilepsy.

¶ Patients who are uncomfortable with the uncertainties of observation may reasonably choose immediate postoperative therapy, even though this approach is associated with more side effects in the short term. In addition, individual risk factors (eg, age >40 to 50 years, preoperative tumor volume ≥4 cm, neurologic deficits) are sometimes used to select patients for immediate further therapy after gross total resection. Practice in this area varies among experts.

Δ Treatment at the time of progression is individualized and may include reresection prior to administration of further therapy. Refer to UpToDate topic on treatment of oligodendroglioma for further details.

◊ Both PCV and temozolomide are reasonable options for adjuvant therapy along with RT in oligodendrogliomas. An ongoing randomized trial in oligodendrogliomas is comparing PCV with concurrent and adjuvant temozolomide. Refer to UpToDate topic on treatment of oligodendrogliomas for further details.