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Health condition · Clinically reviewed

Glioma brain tumours, molecular classification, surgery and precision therapies.

A modern guide for patients and families. Under WHO 2021, biology decides treatment as much as location. See our companion pages on glioma and glioblastoma.

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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 with neuro-oncology experience before publication.

  • 02

    Guideline-anchored

    Cross-checked against NICE, the WHO 2021 CNS tumour classification, EANO and NCCN sources you can inspect at the end.

  • 03

    Current for 2026

    Reflects modern practice: molecular typing (IDH, 1p/19q, MGMT), vorasidenib, BRAF/MEK inhibitors, Optune and proton beam therapy.

Key facts

Glioma at a glance.

The essentials in plain English - what glioma means today, the main subtypes and how UK neuro-oncology treats them.

  • What they are

    A family of primary brain tumours arising from glial cells - astrocytes, oligodendrocytes and ependymal lineages - now defined by molecular biology, not just microscopy.

  • Classification

    WHO 2021 groups gliomas by IDH mutation status, 1p/19q co-deletion, histone H3 mutations and other markers - each pointing to a distinct treatment path.

  • Main subtypes

    IDH-wildtype glioblastoma, IDH-mutant astrocytoma, IDH-mutant and 1p/19q co-deleted oligodendroglioma, and paediatric-type diffuse gliomas.

  • Grade still counts

    WHO grades 1 to 4 remain, but grade is now assigned within a molecular class, so an IDH-mutant grade 4 astrocytoma differs from an IDH-wildtype glioblastoma.

  • Standard of care

    Maximal safe resection followed by radiotherapy, temozolomide (Stupp protocol) and, for eligible patients, tumour-treating fields (Optune).

  • Precision therapy

    Vorasidenib for IDH-mutant low-grade glioma, dabrafenib plus trametinib for BRAF V600E-mutant tumours, and proton beam therapy for selected younger adults.

Why this guide matters

Biology drives the plan.

Under WHO 2021 the same-looking tumour can have very different behaviour depending on IDH, 1p/19q, H3 and BRAF status. Three ideas shape everything below.

  • Molecular class before grade

    IDH-mutant, IDH-wildtype and paediatric-type gliomas behave differently at every grade - treatment is chosen inside the molecular class, not on grade alone.

  • Maximal safe resection matters

    The extent of surgical removal is one of the strongest modifiable predictors of outcome - awake craniotomy and intraoperative imaging exist to make more safe.

  • Targeted therapy is here

    Vorasidenib for IDH-mutant disease and BRAF/MEK inhibitors for BRAF V600E-mutant tumours have changed what is possible for selected patients.

How the diagnosis is made

From first symptom to an integrated diagnosis.

The steps a UK neuro-oncology team will follow, in order, so you know what to expect and why each one matters.

  1. 01

    Assessing

    Neurological history and examination

    A careful history of new headaches, seizures, focal weakness, speech change or personality shift - followed by a full cranial nerve and motor exam.

  2. 02

    Assessing

    Contrast-enhanced MRI brain

    The imaging cornerstone - T1 post-gadolinium, T2/FLAIR, diffusion and perfusion sequences help localise the tumour and estimate grade.

  3. 03

    Assessing

    Advanced MRI when needed

    MR spectroscopy, perfusion (rCBV) and functional MRI refine the differential and map eloquent cortex before surgery.

  4. 04

    Confirming

    Neurosurgical planning

    Multidisciplinary review decides between biopsy, awake craniotomy or asleep resection, guided by tumour location and functional risk.

  5. 05

    Confirming

    Histology and molecular profiling

    Tissue is tested for IDH1/IDH2 mutation, 1p/19q co-deletion, ATRX, TERT promoter, MGMT methylation, CDKN2A/B, BRAF and H3 mutations.

  6. 06

    Preparing

    Integrated WHO 2021 diagnosis

    Histology plus molecular findings produce a single integrated diagnosis that drives treatment intensity and prognosis.

  7. 07

    Preparing

    Staging and baseline function

    Baseline cognition, seizure control, steroid needs and performance status are recorded before treatment begins.

Typical timeline: from first MRI to an integrated WHO 2021 diagnosis in two to four weeks.

Symptoms

What glioma can look like.

Symptoms depend on where in the brain the tumour sits and how quickly it grows. These are the patterns that most often bring people to hospital.

  • New-onset headache

    A new pattern of headache - worse in the morning, on lying flat, or with cough or strain - deserves imaging, especially with other neurological features.

  • First seizure in an adult

    A new focal or generalised seizure in an adult is one of the commonest presentations of a glioma and should trigger MRI.

  • Focal weakness or numbness

    Progressive weakness, clumsiness or sensory change on one side can reflect a growing tumour in the motor or sensory pathways.

  • Speech and language change

    Word-finding difficulty, expressive dysphasia or reading problems point to dominant hemisphere involvement.

  • Personality or cognitive change

    Slowed thinking, apathy, disinhibition or memory decline - especially if noticed by family - can be an early frontal or temporal glioma sign.

  • Visual disturbance

    Field loss, double vision or blurred vision may reflect a tumour affecting the visual pathway, occipital lobe or third nerve.

  • Raised intracranial pressure

    Progressive headache with nausea, vomiting, drowsiness or papilloedema signals raised pressure and needs urgent assessment.

  • Red flag - rapid deterioration

    Sudden severe headache, collapse, uncontrolled seizures or new focal deficit is an emergency - call 999 or attend A&E.

Treatment

How glioma is treated in the UK.

Maximal safe surgery, tailored radiotherapy, temozolomide-based chemotherapy and, for selected patients, vorasidenib, BRAF/MEK inhibitors, Optune and proton beam therapy.

  • Maximal safe resection

    The single most important prognostic step - removing as much tumour as safely possible using neuronavigation, 5-ALA fluorescence and intraoperative MRI where available.

  • Awake craniotomy

    Used when the tumour sits near speech, language or motor cortex - the patient is awakened intraoperatively to map function and preserve it during resection.

  • Radiotherapy

    Fractionated external-beam radiotherapy targeted to the tumour bed and margin - dose and schedule depend on molecular class, age and performance status.

  • Temozolomide (Stupp protocol)

    Concurrent chemoradiotherapy followed by six adjuvant cycles - the standard backbone for glioblastoma and many IDH-mutant grade 3 and 4 tumours.

  • Vorasidenib

    An oral IDH1/IDH2 inhibitor that delays progression in residual or recurrent IDH-mutant grade 2 gliomas - a genuinely new option for younger adults.

  • BRAF plus MEK inhibitors

    Dabrafenib with trametinib for BRAF V600E-mutant gliomas, including some pilocytic astrocytomas and paediatric-type tumours - targeted, oral therapy.

  • Tumour-treating fields (Optune)

    Alternating electric fields delivered via scalp arrays worn continuously - approved for newly-diagnosed and recurrent glioblastoma alongside temozolomide.

  • Proton beam therapy

    Highly conformal radiotherapy that spares surrounding brain - considered for selected younger patients, low-grade gliomas and paediatric-type disease.

Ask about a second opinion

Molecular data is only useful if it changes the plan.

If you have an IDH-mutant, BRAF V600E-mutant or MGMT-methylated tumour and haven’t discussed vorasidenib, dabrafenib plus trametinib or Optune, ask your team - or request a specialist second opinion.

What this guide is based on

The sources behind every claim on this page.

International classification, UK national guidance and the pivotal trials that shape modern glioma treatment.

Key references

Guidelines, classification and pivotal trials.

A quiet reminder

This guide is for information, not medical advice.

Your neuro-oncology team knows your imaging, molecular profile and history and can tell you which parts of this apply to you.

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

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

  • European Association of Neuro-Oncology (EANO) guideline on the diagnosis and treatment of adult diffuse gliomas.

  • National Comprehensive Cancer Network (NCCN). Central Nervous System Cancers guideline.

  • Stupp R et al. Radiotherapy plus concomitant and adjuvant temozolomide for glioblastoma. NEJM.

  • Mellinghoff IK et al. Vorasidenib in IDH1- or IDH2-mutant low-grade glioma (INDIGO trial). NEJM.

Red flags

When glioma needs urgent attention.

A glioma journey needs a low threshold for phoning your team. These are the situations that should trigger an urgent call or A&E visit.

  • Uncontrolled seizures

    Prolonged or clustered seizures need urgent anti-seizure treatment and same-day neurology or A&E review.

  • New focal deficit

    Sudden new weakness, speech loss or visual field defect can indicate tumour bleed, oedema or stroke and warrants emergency imaging.

  • Signs of raised pressure

    Worsening headache with vomiting, drowsiness or reduced consciousness suggests raised intracranial pressure - urgent hospital assessment.

  • Steroid side effects

    Dexamethasone controls oedema but can cause diabetes, mood change, insomnia and infection risk - dose should be tapered as soon as possible.

  • Venous thromboembolism

    Glioma patients have a high risk of DVT and pulmonary embolus - new leg swelling or breathlessness needs same-day review.

  • Post-operative complications

    New neurological deficit, wound infection, CSF leak or seizure after surgery must be reported urgently to the neurosurgical team.

  • Chemoradiotherapy toxicity

    Persistent nausea, low blood counts, fatigue or opportunistic infection during temozolomide need prompt oncology contact.

  • Pseudo-progression

    Apparent MRI worsening within three months of chemoradiotherapy can mimic tumour growth - specialist re-review avoids premature treatment change.

  • Recurrence signals

    New symptoms months or years after treatment - even subtle ones - should prompt an earlier follow-up scan.

Living with it

A serious diagnosis, with real support behind it.

Four practical things that make the biggest difference across the months and years after a glioma diagnosis - team, driving, rehabilitation and community.

A quiet reminder

You do not have to do this alone.

Your clinical nurse specialist, GP and charities are there for the ordinary days, not only the appointments.

  1. 01 Team

    Stay in touch with the neuro-oncology MDT

    A named clinical nurse specialist, oncologist and neurosurgeon working together is the single biggest support you have.

  2. 02 Driving

    Understand DVLA rules

    Seizures and brain tumours affect driving eligibility - your team and the DVLA will guide when and if you can return to the wheel.

  3. 03 Rehab

    Use rehabilitation early

    Physiotherapy, occupational therapy, speech and language therapy and neuropsychology all measurably improve function and mood after treatment.

  4. 04 Support

    Lean on charities and peer networks

    The Brain Tumour Charity, Brain Tumour Research and Maggie’s Centres offer counselling, information and community that hospitals rarely replicate.

Frequently asked

Everything we get asked about glioma.

Straightforward answers on molecular typing, the Stupp protocol, vorasidenib, Optune and proton beam therapy.

  • What is a glioma?

    Glioma is an umbrella term for primary brain tumours that arise from glial cells - the support cells of the central nervous system. Under WHO 2021 they are classified by molecular features such as IDH mutation, 1p/19q co-deletion and histone H3 status, alongside microscopic grade 1 to 4.

  • How is a glioma different from glioblastoma?

    Glioblastoma is a specific WHO grade 4 glioma that is IDH-wildtype in adults. All glioblastomas are gliomas, but not all gliomas are glioblastomas - many are lower-grade, IDH-mutant tumours with a very different prognosis and treatment plan.

  • Why does molecular testing matter so much?

    Two tumours that look identical under the microscope can behave very differently based on their molecular profile. IDH status, 1p/19q co-deletion, MGMT methylation and BRAF mutations directly determine whether temozolomide, vorasidenib or BRAF/MEK inhibitors are likely to help.

  • What is the Stupp protocol?

    The Stupp regimen is concurrent radiotherapy plus daily temozolomide over roughly six weeks, followed by six months of adjuvant temozolomide cycles. It remains the backbone of treatment for newly-diagnosed glioblastoma and many other high-grade gliomas.

  • When is proton beam therapy considered?

    Proton therapy is considered for younger adults, some low-grade gliomas, tumours near critical structures and paediatric-type disease - situations where sparing surrounding brain reduces long-term cognitive and endocrine side effects.

  • What does Optune (tumour-treating fields) do?

    Optune delivers low-intensity alternating electric fields to the tumour through scalp arrays worn for most of the day. Added to temozolomide it has been shown to extend progression-free and overall survival in newly-diagnosed glioblastoma for patients able to wear it consistently.

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