# Brain Lesions in Cancer: Comprehensive Medical Research Compilation
---
## 1. What Are Brain Lesions?
**Definition:** A brain lesion is an area of abnormal tissue in the brain caused by injury, disease, or tumour growth. In the oncology context, brain lesions typically refer to tumour masses — either primary brain cancers or metastases from cancers originating elsewhere in the body.
**Key characteristics:**
- Can be focal (localized) or diffuse (spread throughout brain tissue)
- May cause mass effect (compression of surrounding structures)
- Often surrounded by perilesional oedema (fluid accumulation/swelling)
- Can be single or multiple
- Size ranges from microscopic to several centimetres
**In the context of metastatic adenocarcinoma**, brain lesions represent secondary cancer deposits that have spread from the primary adenocarcinoma site (commonly lung, breast, melanoma, colorectal, or renal) through the bloodstream to the brain parenchyma or meninges.
---
## 2. Types of Brain Lesions: Primary vs. Metastatic
### 2.1 Primary Brain Tumours
Originating within the central nervous system:
| Type | Description | Malignancy |
|------|-------------|------------|
| **Glioblastoma (GBM)** | Most common primary malignant brain tumour; aggressive, infiltrative | Grade IV (high) |
| **Astrocytoma** | Arises from astrocyte cells; grades I–IV | Varies |
| **Meningioma** | Arises from meninges; usually slow-growing | Mostly Grade I (benign) |
| **Oligodendroglioma** | Arises from oligodendrocytes; often IDH-mutant | Grade II–III |
| **Medulloblastoma** | Primitive neuroectodermal tumour; mostly paediatric | Grade IV |
| **Pituitary adenoma** | Arises from pituitary gland; usually benign | Mostly Grade I |
| **Schwannoma** | Arises from nerve sheath (e.g., vestibular schwannoma) | Mostly Grade I |
### 2.2 Metastatic Brain Tumours (Brain Metastases)
Secondary tumours that spread from a cancer elsewhere in the body. **Metastases account for 8–10% of all brain tumours but are 10x more common than primary brain tumours.**
**Most common primary cancers that metastasise to the brain:**
| Primary Cancer | % Developing Brain Mets | Notes |
|----------------|-------------------------|-------|
| **Lung cancer (NSCLC/SCLC)** | 20–40% | #1 source of brain metastases |
| **Breast cancer** | 10–15% | HER2+ and triple-negative subtypes at higher risk |
| **Melanoma** | 40–60% | Highest propensity for brain spread |
| **Colorectal cancer** | 5–10% | Often solitary |
| **Renal cell carcinoma** | 5–10% | Highly vascular |
| **Germ cell tumours** | Variable | Often in young patients |
**Key differences between primary and metastatic brain lesions:**
| Feature | Primary | Metastatic |
|---------|---------|------------|
| Origin | CNS tissue | Extracranial primary |
| Number of lesions | Usually single | Often multiple |
| Location | Throughout brain parenchyma | Typically grey-white matter junction |
| Surrounding oedema | Variable | Often disproportionate to size |
| Prognosis | Depends on grade | Depends on primary cancer control |
---
## 3. Symptoms of Brain Lesions
Symptoms depend on lesion **location, size, number**, and degree of **mass effect** and **cerebral oedema**.
### 3.1 General/Non-Focal Symptoms (Raised ICP)
- **Headache** — typically worse in the morning, worsened by Valsalva (coughing, bending); progressive and unresponsive to standard analgesics
- **Nausea and vomiting** — often projectile, may be independent of food intake
- **Drowsiness/somnolence** — ranging from fatigue to altered level of consciousness
- **Cognitive changes** — confusion, memory impairment, difficulty concentrating
- **Seizures** — can be the presenting symptom; new-onset seizure in adults is a red flag
### 3.2 Focal Neurological Symptoms (Location-Dependent)
| Location | Typical Symptoms |
|----------|-----------------|
| **Frontal lobe** | Personality changes, executive dysfunction, weakness of contralateral leg/face, speech impairment (Broca's if dominant hemisphere) |
| **Parietal lobe** | Sensory deficits, neglect, apraxia, visual-spatial disorientation |
| **Temporal lobe** | Memory impairment, language difficulty (Wernicke's if dominant), visual field defects |
| **Occipital lobe** | Visual disturbances, hemianopsia, cortical blindness |
| **Cerebellum** | Ataxia, dysmetria, dysdiadochokinesia, nystagmus, gait instability |
| **Brainstem** | Cranial nerve palsies, dysphagia, dysarthria, crossed signs, respiratory compromise |
| **Periventricular** | Hydrocephalus, visual changes |
### 3.3 Emergency Red Flags
- Rapidly deteriorating level of consciousness
- New focal weakness or severe headache
- First seizure in an adult with known cancer
- Signs of herniation: fixed and dilated pupil, Cushing's triad (hypertension, bradycardia, irregular respirations)
---
## 4. Diagnosis
### 4.1 Magnetic Resonance Imaging (MRI) — **Gold Standard**
**Protocol for known/suspected brain metastases:**
- **T1-weighted with gadolinium contrast** — best for identifying enhancing lesions; metastases typically show ring or nodular enhancement with surrounding T2/FLAIR hyperintense oedema
- **T2-weighted / FLAIR** — sensitive for oedema and non-enhancing disease
- **Diffusion-weighted imaging (DWI)** — helps differentiate abscess (restricted diffusion) from necrotic tumour
- **Perfusion MRI** — elevated relative cerebral blood volume (rCBV) suggests high-grade tumour vs. radiation necrosis
- **MR spectroscopy** — elevated choline, decreased NAA, lactate peak suggestive of tumour
**Typical MRI appearance of metastases:**
- Well-circumscribed, round lesions at grey-white matter junction
- Disproportionate perilesional vasogenic oedema (T2/FLAIR hyperintensity extending beyond the enhancing rim)
- Multiple lesions in ~50% of cases
### 4.2 Computed Tomography (CT) Head
**Role:**
- First-line imaging in acute/emergency settings (rapidly available)
- **Non-contrast CT** — detects haemorrhage, calcification, hydrocephalus, mass effect, midline shift
- **Contrast-enhanced CT** — less sensitive than MRI but useful when MRI contraindicated (pacemaker, claustrophobia)
**Limitations:**
- Poor sensitivity for posterior fossa lesions (bone artefact)
- May miss small lesions (<5 mm)
- Less detail on oedema extent and tissue characterisation
### 4.3 Positron Emission Tomography (PET)
**Role:**
- **FDG-PET** — limited utility for brain (high background glucose metabolism); useful for identifying the primary tumour when unknown
- **Amino acid PET** (FET-PET, MET-PET) — superior for differentiating tumour recurrence from radiation necrosis
- **Whole-body PET/CT** — essential for staging; evaluates systemic disease burden alongside brain involvement
### 4.4 Additional Diagnostic Tools
- **Biopsy (stereotactic)** — for uncertain diagnosis; distinguishes metastasis from primary brain tumour, infection, or demyelination
- **CSF analysis** — indicated for suspected leptomeningeal disease; cytology, flow cytometry, tumour markers
- **EEG** — for seizure evaluation and classification
- **Oncological markers** — systemic staging to assess overall disease burden
---
## 5. Treatment Options
### 5.1 Surgical Resection
**Indications:**
- Single, accessible lesion with significant mass effect
- Lesion causing symptomatic raised ICP requiring decompression
- Diagnostic uncertainty requiring histological confirmation
- Radio-resistant histology (e.g., melanoma, renal cell carcinoma, colorectal)
- Patient with good performance status (KPS ≥70) and controlled extracranial disease
**Contraindications / Inoperable Lesions:**
| Factor | Detail |
|--------|--------|
| **Deep location** | Brainstem, thalamus, basal ganglia, corpus callosum |
| **Critical eloquent areas** | Motor cortex, language cortex (unless awake craniotomy feasible) |
| **Multiple lesions** | >4 lesions typically not amenable to surgery (though SRS may be used) |
| **Extensive extracranial disease** | Poor systemic control; limited life expectancy |
| **Poor performance status** | KPS <60, ECOG ≥3 |
| **Severe comorbidities** | Uncontrolled medical conditions |
| **Diffuse/multifocal disease** | Leptomeningeal spread, gliomatosis cerebri pattern |
| **Coagulopathy** | Uncorrectable bleeding risk |
**Surgical approaches:**
- Standard craniotomy with microsurgical resection
- **Awake craniotomy** — for lesions in eloquent cortex (real-time language/motor mapping)
- Image-guided / neuronavigation-assisted surgery
- Endoscopic endonasal approach (for sellar/suprasellar lesions)
### 5.2 Stereotactic Radiosurgery (SRS)
**Definition:** Highly focused, high-dose radiation delivered in 1–5 sessions using precise 3D targeting.
**Platforms:**
- **Gamma Knife** (Leksell)
- **Linear accelerator-based** (CyberKnife, Varian Edge, TrueBeam)
- **Proton beam therapy** (increasingly available)
**Indications:**
- Lesions 1–4 cm in diameter (ideal); up to 3–4 cm possible
- 1–4 lesions (historical limit); modern SRS treats up to 10–15 lesions
- Deep-seated or eloquent-area lesions where surgery is high-risk
- Post-operative cavity irradiation after resection
- Patients unsuitable for surgery
- Recurrent or progressive metastases
**Dosing:** Typical single-fraction doses of 16–24 Gy depending on lesion size and proximity to critical structures.
**Advantages:**
- Non-invasive, outpatient procedure
- Preserves neurocognitive function compared to WBRT
- High local control rates (70–90% at 12 months)
- Rapid treatment (single day)
**Limitations:**
- Not effective for lesions >4 cm
- Risk of radiation necrosis (10–15%)
- May not relieve mass effect; steroids often needed post-SRS
### 5.3 Whole-Brain Radiation Therapy (WBRT)
**Indications:**
- Multiple brain metastases (>10–15 lesions)
- Diffuse leptomeningeal disease
- Poorly controlled systemic disease
- Patient not suitable for SRS or surgery
- Symptomatic relief in patients with short life expectancy
**Typical regimens:**
- **30 Gy in 10 fractions** — most common standard
- **20 Gy in 5 fractions** — palliative, for patients with very limited life expectancy
- **37.5 Gy in 15 fractions** — less common, used when fractionation tolerance is needed
**Advantages:**
- Treats entire brain, including microscopic disease
- Available in most centres
- Rapid initiation
**Disadvantages:**
- Significant neurocognitive decline (memory, processing speed, executive function)
- Fatigue, hair loss, skin changes
- Limited local control compared to focal therapy
**Hippocampal-sparing WBRT + memantine:**
- SHIELD trial and RTOG 0614 showed that adding **memantine** (an NMDA receptor antagonist, 5 mg loading then 10 mg daily) to WBRT significantly delays cognitive decline
- Hippocampal avoidance WBRT (HA-WBRT) further reduces cognitive toxicity
### 5.4 Systemic Therapy
**Role in brain metastases:**
- Traditional chemotherapy has **limited CNS penetration** due to the blood-brain barrier (BBB)
- **Targeted therapies** with CNS activity:
- **TKIs for EGFR-mutant NSCLC:** Osimertinib (CNS response rate ~70%), alectinib
- **ALK inhibitors:** Alectinib, lorlatinib (high CNS penetration)
- **HER2-targeted:** Trastuzumab deruxtecan, tucatinib (breast cancer)
- **BRAF/MEK inhibitors:** Dabrafenib + trametinib (melanoma, CNS response ~60%)
- **RET inhibitors:** Selpercatinib, pralsetinib
- **Immunotherapy:** Pembrolizumab, nivolumab (moderate CNS activity; checkpoint inhibitors)
- **Intrathecal chemotherapy:** For leptomeningeal disease (methotrexate, cytarabine, thiotepa)
---
## 6. Management of Brain Swelling (Cerebral Oedema)
### 6.1 Corticosteroids — First-Line Therapy
**Dexamethasone** is the preferred corticosteroid for cerebral oedema due to:
- Minimal mineralocorticoid activity (less sodium/fluid retention)
- Long half-life (~36 hours)
- Potent anti-inflammatory effect
- Good CNS penetration
**Dosing:**
| Clinical Scenario | Initial Dose | Notes |
|-------------------|-------------|-------|
| **Asymptomatic / mild oedema** | 4–8 mg/day (single dose or divided) | Lowest effective dose |
| **Symptomatic / moderate oedema** | 16 mg/day (8 mg BID) | Typical starting dose |
| **Severe oedema / raised ICP** | 96 mg/day (16 mg QID) | High-dose; reduce ASAP |
| **Post-SRS/Surgery** | 8–16 mg/day | Taper over 2–4 weeks |
**Tapering:** Reduce dose by 2–4 mg/day once symptoms improve. Aim for lowest effective dose to minimise side effects.
**Side effects of prolonged dexamethasone use:**
- Hyperglycaemia / new-onset diabetes
- Muscle weakness (steroid myopathy)
- Osteoporosis / avascular necrosis
- Immunosuppression / increased infection risk
- GI ulceration (prophylactic PPI recommended)
- Insomnia, mood changes, psychosis
- Weight gain / Cushingoid appearance
- Adrenal suppression (do not stop abruptly)
**Other corticosteroids:**
- Prednisolone — alternative if dexamethasone unavailable
- Methylprednisolone — occasionally used, particularly in spinal cord compression
### 6.2 Osmotic Diuretics — Acute ICP Management
**Mannitol:**
- **Mechanism:** Creates osmotic gradient, drawing fluid from brain parenchyma into vascular space
- **Dose:** 0.25–1 g/kg IV bolus (20% solution) over 20–30 minutes
- **Duration of effect:** 2–8 hours (varies)
- **Monitoring:** Serum osmolality (target <320 mOsm/kg), renal function, electrolytes, volume status
- **Rebound phenomenon:** Can cause worsened oedema after effects wear off
- **Contraindications:** Anuria, severe dehydration, pulmonary oedema, active intracranial bleeding
**Hypertonic saline (3% NaCl):**
- **Alternative to mannitol**; may be preferred in renal impairment
- **Dose:** 250 mL over 10–30 minutes, or continuous infusion
- **Monitoring:** Serum sodium (target 145–155 mmol/L; avoid >160 mmol/L), volume status
- **Advantages:** No rebound, no renal toxicity, provides volume expansion
### 6.3 Other ICP-Reducing Measures
| Measure | Detail |
|---------|--------|
| **Head elevation** | 30 degrees; promotes venous drainage |
| **Avoid hypercapnia** | Maintain normocapnia (PaCO₂ 35–40 mmHg); CO₂ is a potent cerebral vasodilator |
| **Seizure control** | Prevents secondary ICP elevation from seizures |
| **Avoid sedatives** | Can mask neurological deterioration; use short-acting agents if needed |
| **CSF drainage** | External ventricular drain (EVD) for hydrocephalus |
| **Surgical decompression** | Craniectomy or resection for life-threatening mass effect |
| **Decompressive craniectomy** | For malignant oedema unresponsive to medical management |
| **Hyperventilation** | Temporary (15–30 min) measure; reduces PaCO₂ to 30–35 mmHg; causes cerebral vasoconstriction |
### 6.4 Anti-Oedema Medications (Non-Steroidal)
- **Acetazolamide** — occasionally used for idiopathic intracranial hypertension
- **Bevacizumab** — anti-VEGF monoclonal antibody; shown to rapidly reduce radiation necrosis-related oedema and metastatic oedema; reduces steroid dependence (RTOG 0820, BeReMet trial)
---
## 7. Neurological Rehabilitation
### 7.1 Physical Therapy
- **Gait training** — for ataxia, hemiparesis, balance disorders
- **Strengthening exercises** — addressing weakness and steroid myopathy
- **Functional mobility** — bed transfers, standing, ambulation
- **Fall prevention** — home safety assessment, assistive devices
### 7.2 Occupational Therapy
- **Activities of daily living (ADLs)** — self-care, dressing, bathing
- **Cognitive rehabilitation** — attention, memory, executive function training
- **Visual-perceptual training** — for visual field deficits, spatial neglect
- **Home modifications** — grab bars, ramps, adaptive equipment
- **Energy conservation** — pacing strategies, fatigue management
### 7.3 Speech and Language Therapy
- **Aphasia therapy** — expressive (Broca's) and receptive (Wernicke's) language rehabilitation
- **Dysarthria management** — speech clarity, resonance, rate control
- **Swallowing assessment and therapy** — videofluoroscopic swallow study; dysphagia management; aspiration prevention
- **Cognitive-communication therapy** — for cognitive deficits affecting communication
### 7.4 Neuropsychological Assessment & Intervention
- **Formal cognitive testing** — baseline and serial assessment
- **Memory rehabilitation strategies** — external aids, compensatory techniques
- **Executive function training** — problem-solving, planning, organisation
- **Psychological support** — adjustment to diagnosis, depression/anxiety management
### 7.5 Seizure Management & Rehabilitation
- **Antiepileptic drugs (AEDs):** Levetiracetam (first-line; minimal drug interactions), lacosamide, valproate, lamotrigine
- **Avoid:** Enzyme-inducing AEDs (carbamazepine, phenytoin) due to interactions with chemotherapy/targeted therapy
- **Epilepsy surgery evaluation** — for medically refractory tumour-related epilepsy
---
## 8. Monitoring
### 8.1 Neurological Monitoring
**Clinical assessment:**
- **Neurological examination** — frequent (daily/weekly depending on acuity): mental status, cranial nerves, motor, sensory, cerebellar, reflexes, gait
- **Karnofsky Performance Status (KPS)** and **ECOG status** — functional assessment
- **Rasmussen Neuropsychological Scale** — for cognitive monitoring
### 8.2 Imaging Surveillance
| Scenario | Modality | Timing |
|----------|----------|--------|
| Post-surgery (baseline) | MRI with contrast | 48–72 hours post-op |
| Post-SRS follow-up | MRI with contrast | 3 months, then every 3–6 months |
| Post-WBRT | MRI with contrast | Every 3–4 months |
| Stable disease on systemic therapy | MRI with contrast | Every 3–6 months |
| Symptom change | MRI with contrast | Urgent/same-week |
| Suspected radiation necrosis | MRI + perfusion / PET | As indicated |
**Response assessment criteria:**
- **RANO-BM criteria** (Response Assessment in Neuro-Oncology — Brain Metastases) — standard for evaluating treatment response
- Assesses target lesions, non-target lesions, new lesions, clinical status, steroid use, and neurological function
### 8.3 Systemic Disease Monitoring
- **Whole-body imaging** — CT chest/abdomen/pelvis or PET/CT every 3–4 months
- **Tumour markers** — as appropriate for primary cancer type
- **Treatment-related monitoring** — blood counts, liver/kidney function, ECG (for certain targeted therapies)
### 8.4 Corticosteroid Monitoring
- Blood glucose (daily initially, then as needed)
- Bone density scan (baseline and periodic)
- GI prophylaxis review
- Muscle strength assessment (steroid myopathy screening)
---
## 9. When Are Brain Lesions Removable vs. Inoperable?
### 9.1 Generally Removable (Surgery Appropriate)
A brain lesion is typically considered **surgically removable** when ALL of the following apply:
| Criterion | Details |
|-----------|---------|
| **Single or few lesions** | 1–2 lesions (up to 4 in select cases) |
| **Accessible location** | Supratentorial, cortical/subcortical, cerebellar |
| **Size** | Large lesions (>3 cm) with mass effect benefit most from resection |
| **Good functional status** | KPS ≥70, ECOG 0–2 |
| **Controlled systemic disease** | Stable or responding extracranial disease |
| **Life expectancy** | >3–6 months |
| **Radio-resistant histology** | Melanoma, renal cell carcinoma, colorectal adenocarcinoma |
| **Diagnostic uncertainty** | Tissue diagnosis needed |
### 9.2 Generally Inoperable (Non-Surgical Candidates)
A brain lesion is typically considered **inoperable** when ANY of the following apply:
| Factor | Detail |
|--------|--------|
| **Deep/inaccessible location** | Brainstem, thalamus, basal ganglia, deep white matter tracts, corpus callosum |
| **Eloquent cortex involvement** | Primary motor, sensory, or language areas where resection would cause unacceptable deficit (unless awake craniotomy feasible) |
| **Diffuse/multifocal disease** | >10 lesions; diffuse infiltrative pattern |
| **Leptomeningeal spread** | Diffuse CSF dissemination |
| **Uncontrolled systemic disease** | Widespread, progressive extracranial metastases |
| **Poor performance status** | KPS <60, ECOG ≥3, bedbound |
| **Limited life expectancy** | <1–3 months |
| **Severe comorbidities** | Significant cardiopulmonary, hepatic, or renal disease |
| **Coagulopathy** | Uncorrectable bleeding diathesis |
| **Patient refusal** | Informed decision against surgery |
### 9.3 Decision-Making Framework
The **Grades of Brain Metastases** system provides a structured approach:
| Grade | Criteria | Typical Approach |
|-------|----------|-----------------|
| **1 (Best prognosis)** | Single metastasis, KPS >70, controlled systemic disease, age <65 | Resection + SRS to cavity, or SRS alone |
| **2** | Single metastasis, KPS >70, active systemic disease, OR multiple metastases, KPS >70, controlled systemic disease | SRS preferred; resection if mass effect |
| **3** | Multiple metastases, KPS >70, active systemic disease, OR single metastasis, KPS >70, age >65 | SRS or WBRT + memantine |
| **4 (Poor prognosis)** | Any + KPS <70 | WBRT, or palliative care, or supportive care only |
---
## 10. Palliative Neurological Care
### 10.1 Principles of Palliative Neurological Care for Brain Metastases
Palliative neurological care is **not end-of-life care alone** — it runs concurrently with active treatment from diagnosis onwards. It focuses on symptom control, quality of life, and supporting patients and families through the illness trajectory.
### 10.2 Symptom Management
**Pain management (WHO analgesic ladder):**
| Level | Agents | Brain Metastasis Context |
|-------|--------|--------------------------|
| **Step 1: Mild pain** | Paracetamol, NSAIDs | Headache, general discomfort |
| **Step 2: Moderate pain** | Weak opioids (codeine, tramadol) | Tramadol may lower seizure threshold — use cautiously |
| **Step 3: Severe pain** | Strong opioids (morphine, oxycodone, fentanyl, hydromorphone) | Tumour pain, post-operative pain, bone metastases |
| **Adjuvants** | Gabapentin, pregabalin, duloxetine | Neuropathic pain components |
| **Steroids** | Dexamethasone | Tumour-related pain from oedema/mass effect |
**Seizure management (palliative):**
- Levetiracetam preferred (minimal interactions)
- Midazolam buccal/nasal for acute seizure clusters
- Continuous infusion (midazolam or levetiracetam) for refractory status epilepticus
**Nausea and vomiting:**
- Dexamethasone (also treats oedema)
- Ondansetron (5-HT3 antagonist)
- Metoclopramide (prokinetic + antiemetic)
- Olanzapine (broad-spectrum; useful for refractory nausea)
**Dysphagia:**
- Diet modification (thickened liquids, pureed foods)
- Postural strategies
- Feeding tube consideration (NGT, PEG) — balanced against patient goals
- Palifermin for mucositis-related dysphagia
### 10.3 Neurological Deterioration & End-of-Life Signs
| Sign | Pathophysiology | Management |
|------|-----------------|------------|
| **Decreased consciousness** | Raised ICP, herniation, metabolic disturbance | Positioning, comfort measures, family communication |
| **Agitation/delirium** | Hypoxia, infection, metabolic derangement, steroids, uremia | Haloperidol, midazolam, treat reversible causes when aligned with goals |
| **Dyspnoea** | Raised ICP affecting respiratory centres, pulmonary embolism, pneumonia | Morphine, oxygen, positioning, fan to face |
| **Terminal seizures** | Widespread cortical involvement | Midazolam, levetiracetum, clonazepam |
| **Myoclonus** | Cortical irritation, metabolic encephalopathy | Clonazepam, levetiracetam |
| **Posturing** | Brainstem compression | Decerebrate/decorticate — comfort positioning |
### 10.4 Advance Care Planning
- **Early conversations** — discuss prognosis, treatment goals, values, preferences
- **Advance directives / living will** — documented patient preferences
- **Appointment of proxy decision-maker** — legal representative for healthcare decisions
- **Goals-of-care discussions** — transition from disease-modifying to comfort-focused care
- **Hospice eligibility** — typically KPS <50, ECOG ≥3, or limited life expectancy (<6 months)
### 10.5 Support for Carers and Families
- Information and education about the illness trajectory
- Respite care services
- Psychological support and counselling
- Bereavement support
- Financial and social care navigation
### 10.6 Best Supportive Care (BSC) Alone
For patients with:
- Grade 4 brain metastases
- Diffuse leptomeningeal carcinomatosis
- Uncontrolled widespread systemic disease
- Very poor performance status
BSC may include:
- Symptom-directed steroids (low dose for comfort)
- AEDs for seizure control
- Analgesia
- Careful communication about prognosis
- Early involvement of palliative care / hospice services
---
## 11. Prognosis
Prognosis depends on multiple factors, commonly assessed using the **Graded Prognostic Assessment (GPA) score** for brain metastases:
| Factor | Points |
|--------|--------|
| **Age** | <50 = 0.5; ≥50 = 0 |
| **KPS** | ≥70 = 0.7; <70 = 0 |
| **Controlled primary** | Yes = 0.4; No = 0 |
| **Only one metastasis** | Yes = 0.3; No = 0 |
| **No extracranial metastases** | Yes = 0.3; No = 0 |
**Median overall survival by GPA:**
- **0–1.0:** 1.5 months
- **1.01–2.0:** 4 months
- **2.01–3.0:** 7.1 months
- **3.01–4.0:** 15.4 months
*Note: These figures are from the original GPA model and may not reflect outcomes with modern therapies (SRS, targeted agents, immunotherapy) which have improved survival in many subgroups.*
---
## 12. Summary Treatment Algorithm
```
Patient with brain lesion (known/suspected cancer)
│
├── Acute neurological emergency / raised ICP?
│ └── YES → Dexamethasone + mannitol/hypertonic saline → CT head → urgent neurosurgery review
│
├── MRI brain with gadolinium (if stable)
│
├── Single accessible lesion + good PS + controlled systemic disease?
│ └── YES → Surgical resection → Post-operative SRS to cavity
│
├── 1–4 lesions + deep/ineloquent location?
│ └── YES → Stereotactic Radiosurgery (SRS)
│
├── >10 lesions or diffuse disease?
│ └── YES → WBRT + memantine (or hippocampal-sparing WBRT)
│
├── Targetable mutation?
│ └── YES → Add CNS-penetrant targeted therapy (osimertinib, lorlatinib, etc.)
│
└── Poor PS / extensive systemic disease / inoperable?
└── → Best supportive care ± WBRT → Palliative care involvement
```
---
## References & Key Clinical Trials
1. **RTOG 9508** — SRS + WBRT vs WBRT alone for 1–3 brain metastases
2. **EORTC 22952-26001** — SRS vs WBRT for limited brain metastases
3. **JROSG 99-1** — SRS + WBRT vs SRS alone for 1–3 metastases
4. **RTOG 0614 / NCCTG N0574** — Memantine with WBRT reduces cognitive decline
5. **SHIELD Trial** — Hippocampal avoidance WBRT + memantine
6. **BeReMet Trial** — Bevacizumab for radiation necrosis in brain metastases
7. **NORDIC Trial** — SRS vs SRS + WBRT for 2–4 brain metastases
8. **AWICE Trial** — SRS alone vs WBRT for 2–4 brain metastases
9. **RANO-BM Criteria** — Response assessment in brain metastases
---
*This compilation is for medical research and educational purposes. Clinical decisions should be individualised based on patient-specific factors, multidisciplinary discussion, and current evidence-based guidelines.*