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Health condition · Clinically reviewed

Glioma, from WHO 2021 molecular classification to surgery, radiotherapy and targeted therapy.

The most common primary brain tumours in adults - now defined by histology and molecular markers. Care belongs in specialist commissioned neuro-oncology centres.

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A radiographer guides a patient onto the bed of an advanced 3 Tesla MRI scanner in a London imaging suite

Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a UK-registered clinician before publication.

  • 02

    Sourced from guidance

    Aligned with NICE, NHS England commissioning, WHO 2021 CNS classification and specialist society guidance.

  • 03

    Current for 2026

    Reflects modern molecular classification, vorasidenib for IDH-mutant disease and ONC201 for H3 K27-altered gliomas.

Key facts

Glioma at a glance.

The essentials of glioma in plain English - what it is, the main subtypes and how modern care is organised.

  • What it is

    A group of primary brain tumours arising from glial cells - astrocytes, oligodendrocytes and ependymal cells.

  • How common

    The most common primary brain tumours in adults, with glioblastoma the single most frequent malignant subtype.

  • Classification

    WHO 2021 grades gliomas by histology plus molecular markers - IDH status, 1p/19q, MGMT, ATRX, H3, BRAF and more.

  • Adult subtypes

    Astrocytoma IDH-mutant, oligodendroglioma IDH-mutant 1p/19q-codeleted and glioblastoma IDH-wildtype (grade 4).

  • Paediatric subtypes

    Diffuse midline glioma H3 K27-altered, diffuse hemispheric glioma H3 G34-mutant and circumscribed low-grade gliomas.

  • Treatment core

    Maximal safe resection - then radiotherapy, chemotherapy and targeted therapy tailored to molecular profile.

Why this guide matters

Molecular first, then a plan.

Glioma care has changed fundamentally since WHO 2021. The molecular profile now drives type, grade, treatment and prognosis.

  • Molecular status drives everything

    IDH, 1p/19q, MGMT, ATRX, H3 K27M/G34, BRAF V600E, TERT and EGFR each change how a tumour is classified and treated.

  • Surgery is the foundation

    Maximal safe resection - with intraoperative imaging, 5-ALA and awake mapping where needed - is the strongest lever we have.

  • Targeted therapy is expanding

    Vorasidenib, BRAF-MEK inhibitors and ONC201 are reshaping options for IDH-mutant, BRAF V600E and H3 K27-altered gliomas.

How the diagnosis is made

From first symptoms to an integrated diagnosis.

The pathway a UK neuro-oncology team follows - clinical assessment, imaging, tissue and molecular profiling, then MDT.

  1. 01

    Assessing

    Symptom assessment

    A careful history of headache, seizures, focal neurological change and cognitive or behavioural shift over weeks to months.

  2. 02

    Assessing

    Neurological examination

    Cranial nerves, motor and sensory function, coordination, visual fields and cognition - to localise the lesion.

  3. 03

    Assessing

    MRI brain with gadolinium

    The essential first-line scan - defines the lesion, its enhancement pattern, oedema, midline shift and involvement of eloquent areas.

  4. 04

    Confirming

    Advanced imaging

    MR spectroscopy, perfusion, diffusion and functional MRI or tractography help characterise grade and plan surgery in specialist centres.

  5. 05

    Confirming

    Specialist neuropathology

    Tissue from biopsy or resection is reviewed by a neuropathologist - histology combined with a molecular panel gives the integrated WHO diagnosis.

  6. 06

    Confirming

    Molecular profiling

    IDH1/2, 1p/19q, MGMT, ATRX, TERT, EGFR, BRAF V600E and H3 K27M/G34 - with whole-exome or whole-genome sequencing where commissioned.

  7. 07

    Planning

    Neuro-oncology MDT

    A specialist commissioned MDT (neurosurgery, neuro-oncology, neuroradiology, neuropathology, CNS-CNS) agrees the individualised plan.

Typical timeline: urgent imaging within days, integrated diagnosis and MDT plan within weeks.

Symptoms

What glioma can look like.

Symptoms depend on tumour location, size and grade - from subtle cognitive change to seizure or rapid neurological deterioration.

  • Persistent headache

    Worse in the morning or on lying flat, often with nausea - a common early feature of raised intracranial pressure.

  • New-onset seizures

    Focal or generalised seizures in an adult without prior epilepsy - always warrant urgent brain imaging.

  • Focal neurological deficit

    Weakness, sensory change, speech disturbance or visual field loss - depending on tumour location and size.

  • Cognitive and behavioural change

    Memory loss, personality shift, apathy or executive dysfunction - often noticed first by family.

  • Raised intracranial pressure

    Progressive headache, vomiting, drowsiness and papilloedema - a red flag for urgent assessment.

  • Endocrine or visual features

    Midline and optic pathway gliomas may present with hormonal disturbance or progressive visual loss in children.

  • Paediatric presentation

    Children often present with morning vomiting, unsteadiness, squint or head tilt - low threshold for imaging.

  • Red flag - rapid deterioration

    Rapidly progressive deficit, reduced consciousness or new severe headache - needs same-day emergency assessment.

Treatment

How glioma is treated in the UK.

Maximal safe resection first, then radiotherapy, chemotherapy and molecular targeted therapy - shaped by tumour type, grade and molecular profile.

  • Maximal safe resection

    Specialist neurosurgery with intraoperative MRI, neuronavigation, 5-ALA fluorescence and awake craniotomy where eloquent cortex is involved.

  • Low-grade glioma pathway

    Watch-and-wait for small, incidental lesions or adjuvant radiotherapy plus PCV chemotherapy per RTOG 9802 for higher-risk disease.

  • High-grade Stupp protocol

    Radiotherapy with concurrent and adjuvant temozolomide - the standard backbone for glioblastoma and IDH-wildtype high-grade disease.

  • BRAF plus MEK inhibition

    Dabrafenib and trametinib for BRAF V600E-mutant gliomas - specialist commissioned via national panels.

  • ONC201 for H3 K27-altered

    Dordaviprone (ONC201) and trial-based options for diffuse midline glioma - accessed through specialist paediatric and adult neuro-oncology centres.

  • Vorasidenib for IDH-mutant

    IDH1/2 inhibitor (Voranigo) - FDA-approved 2024 for residual or recurrent grade 2 IDH-mutant glioma, MHRA authorisation pending.

  • Tumour-treating fields

    Alternating electric field therapy added to temozolomide for newly diagnosed glioblastoma - specialist commissioned.

  • Recurrence and salvage therapy

    Bevacizumab, regorafenib, lomustine, re-irradiation and clinical trials of immunotherapy or CAR-T - through specialist commissioned services.

What this guide is based on

The sources behind every claim on this page.

UK national guidance, WHO classification and specialist society standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your neuro-oncology team knows your imaging, molecular profile and history. If you have new or worsening neurological symptoms, seek urgent medical assessment.

  • WHO Classification of Tumours of the Central Nervous System, 5th edition (2021).

  • NICE. Brain tumours (primary) and brain metastases in adults (NG99).

  • NHS England. Specialised neuro-oncology and paediatric neuro-oncology service specifications.

  • EANO. European Association of Neuro-Oncology guidelines for adult diffuse gliomas.

  • SIOP Europe. Paediatric neuro-oncology consensus statements.

  • The Brain Tumour Charity and Brain Tumour Research - patient information standards.

Red flags

When glioma needs urgent attention.

Any of the features below warrant urgent neurological assessment and imaging - and, where confirmed, specialist neuro-oncology referral.

  • New adult-onset seizure

    Any first seizure in an adult warrants urgent brain imaging to exclude a structural lesion including glioma.

  • Progressive focal deficit

    Weakness, dysphasia or hemianopia developing over days to weeks - needs urgent neurology or neurosurgery review.

  • Raised intracranial pressure

    Morning headache, vomiting, papilloedema or reduced consciousness - a neurosurgical emergency.

  • Rapid cognitive decline

    Marked personality or memory change over weeks - always image before attributing to mood or dementia.

  • Paediatric morning vomiting

    Persistent early-morning vomiting, unsteady gait or head tilt in a child - low threshold for urgent MRI.

  • Cauda-like spinal features

    Spinal cord gliomas may cause progressive limb weakness, sensory level or sphincter change - urgent spinal MRI.

  • Hydrocephalus

    Ventricular obstruction from midline or intraventricular gliomas can cause rapid deterioration - emergency neurosurgical assessment.

  • Neurofibromatosis or tuberous sclerosis

    Optic pathway gliomas and SEGAs occur in phakomatoses - surveillance imaging is part of specialist care.

  • Psychological distress

    Diagnosis of a brain tumour carries a heavy emotional load - early access to neuro-oncology counselling and charity support matters.

Living with it

A serious diagnosis, with real support.

Glioma affects work, driving, relationships and identity. A strong multidisciplinary team, rehabilitation and charity partners make an enormous difference.

A quiet reminder

You do not have to face this alone.

Ask your team about neuro-oncology clinical nurse specialists, rehabilitation services and charities such as The Brain Tumour Charity and Brain Tumour Research.

  1. 01 Team

    Lean on the MDT

    Neurosurgery, neuro-oncology, neuropathology, CNS clinical nurse specialists and rehabilitation - each has a defined role in your pathway.

  2. 02 Function

    Rehabilitation matters

    Neuro-rehabilitation, speech and language therapy and occupational therapy help preserve independence after surgery or radiotherapy.

  3. 03 Seizures

    Seizure control

    Anti-seizure medication, driving advice and DVLA notification are part of routine care - your team will guide you.

  4. 04 Support

    Charity and peer support

    The Brain Tumour Charity, Brain Tumour Research and Children with Cancer UK offer information, grants and community.

Frequently asked

Everything we get asked about glioma.

Quick answers on classification, diagnosis, treatment and where care should take place.

  • What is a glioma?

    A glioma is a primary brain tumour that arises from glial cells - the supporting cells of the central nervous system. It includes astrocytomas, oligodendrogliomas, ependymomas and mixed lineage tumours. The WHO 2021 classification groups gliomas by both histology and molecular features such as IDH status and 1p/19q codeletion.

  • How is glioma diagnosed?

    Diagnosis starts with MRI of the brain with gadolinium contrast, often supplemented by advanced imaging such as spectroscopy or perfusion. A definitive diagnosis needs tissue, obtained by biopsy or resection, with specialist neuropathology and a molecular panel covering IDH, 1p/19q, MGMT, ATRX, TERT, BRAF, EGFR and H3 alterations. Whole-exome or whole-genome sequencing is used in specialist commissioned centres.

  • What does the WHO 2021 classification change?

    The WHO 2021 CNS classification integrates histology with molecular markers to define tumour type and grade. For example, glioblastoma is now defined as IDH-wildtype grade 4 disease, while astrocytoma IDH-mutant and oligodendroglioma IDH-mutant 1p/19q-codeleted are separate entities. Paediatric-type diffuse gliomas including H3 K27-altered diffuse midline glioma are recognised as distinct.

  • How is glioma treated?

    Treatment is individualised by tumour type, grade, molecular profile, location and patient factors. It typically starts with maximal safe surgical resection, followed by radiotherapy and chemotherapy where indicated. Molecular targeted therapy - such as BRAF-MEK inhibition, IDH inhibitors like vorasidenib or ONC201 for H3 K27-altered disease - is used through specialist commissioned pathways.

  • What is vorasidenib and who is it for?

    Vorasidenib (Voranigo) is an oral IDH1/2 inhibitor approved by the FDA in 2024 for residual or recurrent grade 2 IDH-mutant astrocytoma or oligodendroglioma after surgery. It delays progression and the need for radiotherapy or chemotherapy in eligible patients. MHRA authorisation in the UK is pending and access is expected through specialist commissioned neuro-oncology services.

  • Where should glioma care take place?

    Glioma care should be delivered in NHS England specialist commissioned neuro-oncology centres with a full multidisciplinary team, specialist neuropathology and access to molecular testing, advanced radiotherapy including proton beam therapy where appropriate, and clinical trials. Paediatric patients should be treated in principal treatment centres for children and young people with cancer.

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