Skip to main content

Health condition · Clinically reviewed

Brain metastases, focal radiosurgery, surgery and CNS-penetrant systemic therapy.

Brain metastases are the most common intracranial tumour in adults. Modern care is precise, focal and combined with drugs that cross the blood-brain barrier.

Jump to treatment
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 neuro-oncology clinician before publication.

  • 02

    Sourced from guidance

    Checked against NICE, ASTRO, EANO and peer-reviewed neuro-oncology sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern practice including stereotactic radiosurgery, hippocampal-sparing WBRT and CNS-penetrant targeted therapy.

Key facts

Brain metastases at a glance.

The essentials, in plain English. Where they come from, where they sit and how modern UK neuro-oncology teams treat them.

  • What it is

    Secondary cancer that has spread to the brain from a primary tumour elsewhere in the body. The most common intracranial tumour in adults.

  • How common

    Around ten times more frequent than primary brain tumours. Roughly 20 to 40 per cent of cancer patients develop brain metastases during their illness.

  • Where from

    Lung around half of cases, breast 15 to 25 per cent, melanoma about 10 per cent, then colorectal, kidney (RCC) and unknown primary.

  • Where they sit

    Around 80 per cent in the cerebral hemispheres at the grey-white junction, 15 per cent in the cerebellum and 5 per cent in the brainstem. Often multiple.

  • Oligometastatic

    One to four (and up to ten) lesions are usually treated with focal stereotactic radiosurgery to preserve cognition.

  • Systemic era

    CNS-penetrant targeted therapy and immunotherapy have transformed outcomes for lung, breast HER2, melanoma and RCC brain metastases.

Why this guide matters

A precise, combined approach.

The outlook for brain metastases has changed profoundly in the last decade. The three points below shape everything else on this page.

  • Focal, not whole brain, first

    For most people with a small number of lesions, stereotactic radiosurgery preserves cognition and delivers around 90 per cent local control.

  • Molecular profiling changes options

    HER2, EGFR, ALK, BRAF, KRAS G12C, MET and RET testing unlocks CNS-penetrant targeted drugs that used to be unavailable for brain disease.

  • Immunotherapy reaches the brain

    Modern checkpoint inhibitors, particularly for melanoma, lung cancer and RCC, produce durable intracranial responses.

How the diagnosis is made

From first scan to a clear neuro-oncology plan.

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

  1. 01

    Imaging

    MRI brain with gadolinium

    The gold-standard scan. Shows number, size and pattern of lesions. Classic finding is multiple ring-enhancing lesions at the grey-white junction.

  2. 02

    Imaging

    CT if MRI is contraindicated

    Used when a pacemaker, cochlear implant or claustrophobia prevents MRI. Less sensitive for small or posterior-fossa disease.

  3. 03

    Imaging

    Advanced imaging

    MR perfusion, MR spectroscopy and PET help tell a metastasis from a primary brain tumour or radionecrosis after treatment.

  4. 04

    Confirming

    Staging and prognostic scoring

    Full staging of the primary cancer plus Karnofsky Performance Status, RPA class and DS-GPA score to guide intensity of treatment.

  5. 05

    Confirming

    Selective biopsy

    Reserved for unknown primary, a solitary lesion where the diagnosis is uncertain, or when tissue is needed for molecular testing.

  6. 06

    Confirming

    CSF studies if leptomeningeal

    Cytology and flow cytometry from a lumbar puncture when cranial neuropathies, polyradiculopathy or hydrocephalus suggest leptomeningeal spread.

  7. 07

    Profiling

    Tumour molecular profiling

    Profiling the primary and, where possible, the brain lesion. HER2 in breast, EGFR and ALK in lung, BRAF in melanoma and more, to identify CNS-penetrant targeted therapy.

Typical timeline: from suspicious scan to a specialist MDT plan within one to two weeks in the UK.

Symptoms

What brain metastases can feel like.

Symptoms depend on where lesions sit and how much oedema surrounds them. Some are subtle. Others need urgent attention.

  • Headache

    Often new, progressive and worse in the morning or with straining. Reflects raised intracranial pressure or oedema around a lesion.

  • Focal neurological deficit

    Weakness, numbness, visual field loss, dysphasia or clumsiness depending on which part of the brain is involved.

  • Seizures

    New-onset focal or generalised seizures. Present in around a quarter of patients at diagnosis and always warrant urgent imaging.

  • Cognitive and personality change

    Memory loss, slowed thinking, altered mood or behaviour. Sometimes the earliest sign, especially with frontal-lobe disease.

  • Raised intracranial pressure

    Nausea, vomiting, drowsiness and papilloedema. A medical emergency needing steroids and urgent neurosurgical assessment.

  • Gait disturbance and ataxia

    Unsteady walking, falls and coordination problems. Suggests cerebellar or brainstem involvement.

  • Hydrocephalus

    Blockage of cerebrospinal fluid flow by a posterior-fossa lesion or leptomeningeal disease. May need a shunt or drain.

  • Leptomeningeal features

    Cranial nerve palsies, radicular pain, polyradiculopathy or gait ataxia. Points to spread through the meninges rather than a solid deposit.

Treatment

How brain metastases are treated.

Steroids and anti-seizure cover, focal radiosurgery or surgery for oligometastatic disease, hippocampal-sparing whole-brain radiotherapy where needed, and CNS-penetrant systemic therapy tuned to the tumour type.

  • Dexamethasone

    Steroid used at 4 to 16 mg per day to reduce oedema and relieve symptoms. Weaned as soon as possible to limit side effects.

  • Anti-epileptic drug

    Levetiracetam is first-line for patients who have had a seizure. Prophylactic use is not recommended without a documented seizure.

  • Neurosurgical resection

    Considered for large, solitary, accessible or posterior-fossa lesions and for unknown primary cancers. The classic Patchell trial supports resection plus radiotherapy.

  • Stereotactic radiosurgery (SRS)

    Gamma Knife, CyberKnife or LINAC-based SRS is first-line for small lesions up to 3 cm and up to around ten lesions. Local control approaches 90 per cent and cognition is largely preserved.

  • Fractionated SRS

    Delivered over three to five sessions for lesions larger than 3 cm or close to critical structures such as the brainstem or optic apparatus.

  • SRS to the surgical cavity

    Given after resection to reduce local recurrence, supported by the N107C trial. Preferred over whole-brain radiotherapy in most oligometastatic cases.

  • Hippocampal-sparing WBRT

    Whole-brain radiotherapy with hippocampal avoidance plus memantine, per NRG-CC001, reduces cognitive decline when diffuse or numerous lesions need treating.

  • CNS-penetrant systemic therapy

    Osimertinib, alectinib, tucatinib with trastuzumab-deruxtecan, dabrafenib-trametinib, immune checkpoint inhibitors and other tumour-specific agents that cross the blood-brain barrier.

Special situations

Leptomeningeal disease

Spread through the meninges is treated with intrathecal chemotherapy (methotrexate, cytarabine, trastuzumab in HER2 breast), focal radiotherapy and CNS-penetrant systemic therapy. Prognosis remains guarded and specialist input is essential.

Radionecrosis after SRS

New enhancement after radiosurgery must be differentiated from progression using advanced MRI or biopsy. Options include steroids, bevacizumab, surgical debulking, hyperbaric oxygen in selected cases and laser interstitial thermal therapy (LITT).

What this guide is based on

The sources behind every claim on this page.

UK national guidance, international specialist society standards and landmark trials, current at the time of last review.

Key references

Guidelines and trials we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your neuro-oncology, oncology and neurosurgery team knows your scans and history and can tell you which parts apply to you. If in doubt, get seen.

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

  • ASTRO. Clinical practice guideline on radiation therapy for brain metastases (2022).

  • EANO-ESMO. Clinical practice guidelines for diagnosis, treatment and follow-up of patients with brain metastasis from solid tumours.

  • Patchell RA et al. Postoperative radiotherapy in the treatment of single metastases to the brain.

  • Yamamoto M et al. JLGK0901 - stereotactic radiosurgery for patients with multiple brain metastases.

  • Brown PD et al. NRG Oncology CC001 - hippocampal avoidance during whole-brain radiotherapy.

  • CheckMate 204 and DESTINY-Breast03 registration data for brain-metastasis cohorts.

Red flags

When brain metastases need urgent attention.

Some symptoms and complications need same-day assessment. If any of these apply, contact your oncology team or attend the emergency department.

  • Sudden severe headache

    Thunderclap headache or a rapidly progressive headache with vomiting suggests raised intracranial pressure or bleeding into a metastasis. Needs same-day imaging.

  • New seizure

    A first seizure in an adult with known cancer is a brain metastasis until proven otherwise. Attend the emergency department for urgent MRI and neurology review.

  • Progressive weakness or speech loss

    A stroke-like presentation in a cancer patient can be a metastasis, bleed or true stroke. All three need emergency assessment.

  • Drowsiness and vomiting

    Signs of raised intracranial pressure or hydrocephalus. Treat as a neurosurgical emergency with high-dose dexamethasone and urgent scan.

  • Cranial nerve palsies

    Double vision, facial weakness or swallowing problems in a cancer patient can point to leptomeningeal disease. Discuss with the neuro-oncology team.

  • Bleeding into a metastasis

    Melanoma, renal, thyroid and choriocarcinoma metastases are prone to haemorrhage. Sudden neurological change warrants urgent CT.

  • Suspected radionecrosis

    New enhancement months to years after radiosurgery may be treatment change, not progression. Advanced MRI or biopsy is often needed to decide.

  • Cauda equina from leptomeningeal spread

    New back pain, saddle numbness or bladder or bowel change in a cancer patient is a red flag for spinal leptomeningeal disease.

  • Steroid complications

    Hyperglycaemia, infection, insomnia and mood change on dexamethasone. Wean to the lowest effective dose as soon as symptoms allow.

Living with it

Complex disease, clearer options than ever.

Four things that make the biggest difference. A specialist MDT, molecular profiling, cognition-sparing radiotherapy and the right support behind you.

A quiet reminder

Ask about surveillance and rehab, not just treatment.

Surveillance MRI every two to three months, neuro-rehabilitation, palliative-care input and psychological support are as much a part of good care as the radiotherapy plan itself.

  1. 01 Team

    Ask for a neuro-oncology MDT

    Modern care combines neurosurgery, radiation oncology, medical oncology and neurology. If your care feels fragmented, ask to be discussed at an MDT.

  2. 02 Molecular

    Push for tumour profiling

    CNS-penetrant targeted therapy depends on knowing the tumour genetics. Make sure the primary, and where possible the brain lesion, have been profiled.

  3. 03 Cognition

    Protect thinking and memory

    Where suitable, focal SRS or hippocampal-sparing whole-brain radiotherapy with memantine preserves cognition better than older techniques.

  4. 04 Support

    Use the charities that know this

    Macmillan, The Brain Tumour Charity, brainstrust and cancer-specific charities offer practical help, benefits advice and peer support.

Frequently asked

Everything we get asked about brain metastases.

Quick answers on MRI, radiosurgery, surgery, systemic therapy and radionecrosis.

  • What are brain metastases?

    Brain metastases are cancer deposits that have spread to the brain from a primary tumour elsewhere in the body. They are the most common intracranial tumour in adults and occur in roughly 20 to 40 per cent of people with cancer. The most frequent primary sources are lung (about half of cases), breast, melanoma, colorectal cancer, kidney cancer and unknown primary.

  • How are brain metastases diagnosed?

    The gold-standard investigation is an MRI brain scan with gadolinium contrast, which shows the number, size and pattern of lesions. CT is used when MRI is not possible. Advanced MRI techniques and PET help distinguish a metastasis from a primary brain tumour or from radionecrosis after previous treatment. Tumour molecular profiling of the primary, and sometimes of the brain lesion itself, guides systemic therapy.

  • Is stereotactic radiosurgery better than whole-brain radiotherapy?

    For most patients with one to four (and up to about ten) small brain metastases, focal stereotactic radiosurgery gives excellent local control of around 90 per cent and preserves cognition much better than whole-brain radiotherapy. Whole-brain radiotherapy still has a role for diffuse, numerous or leptomeningeal disease, and modern hippocampal-sparing techniques with memantine reduce the cognitive impact.

  • When is surgery needed for a brain metastasis?

    Surgery is considered for large, solitary or accessible lesions, for lesions in the posterior fossa causing pressure or hydrocephalus, and when the primary cancer is unknown and tissue is needed for diagnosis. Post-operative radiotherapy, usually to the surgical cavity, reduces the chance of local recurrence.

  • Can drug therapy alone treat brain metastases?

    For some cancers, yes. CNS-penetrant targeted drugs such as osimertinib in EGFR-mutant lung cancer, alectinib and lorlatinib in ALK-positive lung cancer, tucatinib with trastuzumab-deruxtecan in HER2 breast cancer and dabrafenib-trametinib in BRAF-mutant melanoma can achieve intracranial responses. Immunotherapy, particularly combinations in melanoma, also penetrates the central nervous system. Radiotherapy and systemic therapy are increasingly used together rather than in sequence.

  • What is radionecrosis and how is it treated?

    Radionecrosis is inflammation and tissue damage that can appear months to years after stereotactic radiosurgery, and looks very similar to tumour progression on scans. Advanced MRI or biopsy may be needed to tell them apart. Treatment options include steroids, bevacizumab, surgery, hyperbaric oxygen in selected cases and laser interstitial thermal therapy (LITT).

Related content

Keep reading.

Pulse Healthcare concierge

Send us your enquiry

A concierge service for UK private healthcare. We match you with the best vetted clinics and consultants in our network - they then contact you directly.

So we can match you to the right clinician close to you.

We reply to every enquiry within 24 hours (Mon–Fri). Confidential - your details are never shared outside our vetted consultant network.