Management of Low-Grade Glioma

Initial Surgical Approach

The National Comprehensive Cancer Network recommends maximal safe surgical resection as the cornerstone of low-grade glioma management, with the extent of resection being the most critical modifiable prognostic factor, aiming for complete removal of T2/FLAIR abnormality when safely achievable 1, 2, 3
The goal of surgery is total or subtotal removal of the tumor volume defined on T2-weighted or FLAIR MRI sequences, with postoperative MRI verification within 24-72 hours using T2-weighted or FLAIR sequences 1, 2, 4, 5

The National Comprehensive Cancer Network recommends obtaining 1p/19q deletion testing for all tumors with oligodendroglial components, as codeletion is a favorable prognostic factor and influences treatment decisions, and determining IDH1/IDH2 mutation status, as mutations indicate significantly better prognosis 1, 2, 7

The National Comprehensive Cancer Network identifies low-risk features, including age ≤40 years, Karnofsky Performance Status ≥70, minor or no neurologic deficit, oligodendroglioma or mixed oligoastrocytoma histology, tumor <6 cm, 1p/19q codeletion, and IDH1/IDH2 mutation, and high-risk features, including age >40 years, KPS <70, tumor >6 cm, tumor crossing midline, preoperative neurologic deficit, increased perfusion on imaging, absence of 1p/19q codeletion, and wild-type IDH1/IDH2 1, 2, 4, 7

For low-risk patients after gross total resection, observation with close surveillance is appropriate, while for high-risk patients, adjuvant radiotherapy (45-54 Gy) or chemotherapy is recommended 1, 2, 3, 4
For patients with oligodendrogliomas with 1p/19q codeletion, chemotherapy (temozolomide or PCV) is particularly recommended, especially in symptomatic cases 2, 3, 7

The standard dose of radiation therapy is 45-54 Gy (recommended 50-54 Gy) in 1.8-2.0 Gy fractions, with a target volume defined using T2-weighted/FLAIR sequences with 1-2 cm margin, and stereotactic radiosurgery has no established role in low-grade glioma management 1, 2, 3, 4, 5, 6

Temozolomide, PCV (lomustine, procarbazine, vincristine), nitrosourea-based regimens, and platinum-based therapy are chemotherapy options for adjuvant or recurrent disease 2, 3, 7

MRI every 3-6 months for 5 years, then at least annually, using T2-weighted and FLAIR sequences, with more frequent imaging (every 2-4 months) for patients in the first 2-3 years post-treatment 1, 6

Surgery is recommended if resectable, followed by chemotherapy in patients who previously received radiotherapy, and consideration of alternative chemotherapy regimens, re-irradiation, or palliative/best supportive care 1, 2, 4