# CIM Case: Spinal Cord Compression - Thoracic Metastasis ## Clinical Scenario **Patient:** 70-year-old man **Presentation:** 12-month history of progressive low thoracic back pain, now developing bilateral leg weakness over past 2 weeks **Relevant history:** Previously healthy, no prior malignancy, 30 pack-year smoking history (quit 10 years ago), 5kg weight loss over 6 months, no urinary or bowel symptoms (yet), no prior spine surgery **Examination findings:** - Thin, cachectic man - Point tenderness over T10-T11 spinous processes - Lower limb examination: - Power 4/5 bilateral hip flexors and knee extensors - Power 3/5 bilateral ankle dorsiflexors - Increased tone bilaterally - Brisk knee and ankle reflexes - Upgoing plantars (Babinski positive) bilaterally - Sensory level at T10 (reduced sensation below) - Anal tone intact, no saddle anaesthesia - Gait wide-based, uses walking stick --- ## Investigations Provided ### Laboratory Results | Test | Result | Normal Range | Interpretation | |------|--------|--------------|----------------| | Hb | 105 g/L | 130-170 g/L | ↓ Anaemia of chronic disease | | WCC | 9.5 ×10⁹/L | 4-11 ×10⁹/L | Normal | | Platelets | 185 ×10⁹/L | 150-400 ×10⁹/L | Normal | | CRP | 28 mg/L | <5 mg/L | ↑ Elevated | | ESR | 65 mm/hr | <20 mm/hr | ↑ Elevated | | Calcium | 2.45 mmol/L | 2.2-2.6 mmol/L | Normal | | Phosphate | 1.0 mmol/L | 0.8-1.5 mmol/L | Normal | | ALP | 185 U/L | 30-120 U/L | ↑ Elevated | | Albumin | 30 g/L | 35-50 g/L | ↓ Low | | PSA | 3.2 ng/mL | <4 ng/mL | Normal | | Protein electrophoresis | No paraprotein | - | Excludes myeloma | | LDH | 320 U/L | 120-250 U/L | ↑ Elevated | | Creatinine | 95 μmol/L | 60-110 μmol/L | Normal | ### Imaging **Image 1: Thoracic Spine X-ray** **Radiological features:** - Collapse of T10 vertebral body - Loss of vertebral height anteriorly - Pedicle destruction on AP view ("winking owl" sign) - Increased kyphosis at T10 level - No obvious lytic lesions elsewhere on plain film **Image 2: MRI Thoracic Spine (T1, T2, STIR)** **Findings:** - T10 vertebral body collapse with posterior retropulsion - **Epidural tumour extension** causing cord compression - Cord signal change at T10 level (myelomalacia) - T1 hypointense lesion replacing normal marrow signal - Additional lesions at T6 and L2 (not causing cord compression) - Paraspinal soft tissue mass **Image 3: CT Chest/Abdomen/Pelvis (Staging)** **Findings:** - 3.5cm spiculated mass in right upper lobe (primary lung cancer) - Ipsilateral hilar lymphadenopathy - Multiple small pulmonary nodules - No liver metastases - No adrenal metastases - Multiple bone lesions on bone windows --- ## Questions & Model Answers **Diagnosis: Metastatic Epidural Spinal Cord Compression (MESCC)** - Primary: Likely non-small cell lung carcinoma - Level: T10 with epidural extension and cord compression - Additional skeletal metastases at T6 and L2 **This is a Surgical Emergency Because:** | Feature | Significance | |---------|--------------| | Progressive weakness | Neurological deterioration ongoing | | Upper motor neuron signs | Spinal cord (not cauda equina) involvement | | Sensory level | Confirms cord compression | | Cord signal change on MRI | Myelomalacia - may be irreversible | | Ambulatory but deteriorating | Window for intervention closing | **Timing:** | Neurological Status | Recommended Timing | |---------------------|-------------------| | Non-ambulatory, <24h | Emergency surgery within hours | | Ambulatory but deteriorating | Urgent surgery within 24-48h | | Stable neurology | Semi-urgent, can plan surgery | | Complete paraplegia >48h | Surgery unlikely to restore function | **This Patient: Ambulatory but deteriorating → Urgent (24-48 hours)** > **Consultant Tip:** Once a patient becomes non-ambulatory from MESCC, the chance of walking again is only 10%. Operate while they can still walk! **Tokuhashi Score (Revised):** | Parameter | Score | This Patient | |-----------|-------|--------------| | **General condition (KPS)** | 0-2 | 1 (poor: 50-70%) | | **Number of extraspinal bone mets** | 0-2 | 1 (1-2 lesions) | | **Number of vertebral mets** | 0-2 | 1 (2 vertebrae) | | **Visceral mets** | 0-2 | 0 (lung nodules present) | | **Primary tumour type** | 0-5 | 1 (lung = poor prognosis) | | **Neurological status** | 0-2 | 1 (Frankel C/D) | | **Total** | 0-15 | **5** | **Tokuhashi Interpretation:** | Score | Prognosis | Recommended Treatment | |-------|-----------|----------------------| | 0-8 | <6 months survival | Palliative/radiotherapy | | 9-11 | 6-12 months survival | Palliative or excisional surgery | | 12-15 | >12 months survival | Excisional surgery | **SINS Score (Spinal Instability Neoplastic Score):** | Parameter | Score | This Patient | |-----------|-------|--------------| | Location | 0-3 | 2 (thoracic T3-T10) | | Mechanical pain | 0-3 | 3 (yes, with movement) | | Lesion type | 0-2 | 2 (lytic) | | Alignment | 0-4 | 2 (kyphosis present) | | Vertebral body involvement | 0-3 | 3 (>50% collapse) | | Posterior element involvement | 0-3 | 1 (unilateral) | | **Total** | 0-18 | **13** | **SINS Interpretation:** | Score | Stability | Recommendation | |-------|-----------|----------------| | 0-6 | Stable | Non-surgical | | 7-12 | Indeterminate | Surgical consult | | 13-18 | Unstable | Surgical stabilisation | **This Patient: SINS 13 = Unstable → Needs surgical stabilisation** > **Consultant Tip:** SINS score predicts mechanical instability and guides stabilisation. Tokuhashi predicts survival and guides extent of surgery. Use both together. **Evidence Base: Patchell Trial (2005)** Landmark RCT comparing surgery + radiotherapy vs radiotherapy alone for MESCC: | Outcome | Surgery + RT | RT Alone | |---------|-------------|----------| | Ambulatory post-treatment | 84% | 57% | | Retained ambulatory status | 62% | 19% | | Median survival | 126 days | 100 days | | Bladder function preserved | 62% | 32% | **Indications for Surgery:** | Indication | Rationale | |------------|-----------| | Single level compression | Focal intervention effective | | Mechanical instability (SINS >12) | RT cannot stabilise | | Radioresistant tumour | Renal, melanoma, sarcoma | | Unknown histology | Need tissue diagnosis | | Neurological deterioration despite RT | Salvage decompression | | Spinal cord compression causing symptoms | Direct decompression | **Indications for Radiotherapy Alone:** | Indication | Rationale | |------------|-----------| | Radiosensitive tumour (myeloma, lymphoma) | Responds well to RT | | Multiple levels of compression | Surgery too extensive | | Very poor prognosis (<3 months) | Surgery morbidity outweighs benefit | | Medically unfit for surgery | Anaesthetic risk too high | | Complete paraplegia >48 hours | Unlikely to recover function | **This Patient:** - Single dominant level (T10) - Mechanical instability (SINS 13) - Progressive neurology - Fit for surgery **→ Surgery + adjuvant radiotherapy recommended** > **Consultant Tip:** The Patchell trial changed practice - surgery + RT is better than RT alone for most patients with MESCC. But patient selection is key. **Surgical Goals:** 1. Decompress spinal cord 2. Stabilise spine 3. Obtain tissue for histology 4. Enable adjuvant radiotherapy **Approach Options:** | Approach | Indication | This Patient | |----------|------------|--------------| | **Posterior decompression + stabilisation** | Most cases, cord compression from any direction | ✓ Recommended | | Anterior corpectomy + reconstruction | Anterior disease, single level, no posterior involvement | Not ideal (posterior disease) | | Combined anterior-posterior | Extensive disease, 360° involvement | May be needed | **Posterior Approach Technique:** | Step | Description | |------|-------------| | 1. Positioning | Prone, Montreal mattress, neuromonitoring | | 2. Exposure | Midline incision, expose T8-T12 | | 3. Pedicle screws | T8, T9, T11, T12 (skip T10) | | 4. Laminectomy | T10 (± adjacent levels) for decompression | | 5. Tumour debulking | Intralesional excision, decompress cord circumferentially | | 6. Posterior stabilisation | Rods, crosslinks | | 7. Anterior support | Cement augmentation if needed | **Instrumentation Considerations:** | Factor | Recommendation | |--------|----------------| | Levels of fixation | 2 above, 2 below lesion | | Screw type | Polyaxial pedicle screws | | Cement augmentation | If osteoporotic or poor bone quality | | Crosslinks | Yes - adds rotational stability | **Intraoperative Neuromonitoring:** - SSEPs (sensory) - MEPs (motor) - EMG (nerve roots) - Baseline before positioning - Alert surgeon to changes during decompression > **Consultant Tip:** In metastatic disease, you're not aiming for cure. The goal is rapid, effective decompression and stabilisation with minimal morbidity. Don't chase every tumour cell. **Post-operative Radiotherapy:** | Parameter | Details | |-----------|---------| | Timing | 2-4 weeks post-surgery (wound healing) | | Dose | 30 Gy in 10 fractions (standard) | | Alternative | 8 Gy single fraction (palliative) | | Target | Treated level + 1 above/below | | SBRT | May be used for radioresistant tumours | **Systemic Therapy:** | Treatment | Indication | |-----------|------------| | Chemotherapy | Based on histology (lung = platinum-based) | | Targeted therapy | EGFR/ALK mutations in NSCLC | | Immunotherapy | Checkpoint inhibitors (PD-L1) | | Bisphosphonates | Zoledronic acid - reduces skeletal events | | Denosumab | Alternative bone-modifying agent | **Supportive Care:** | Measure | Purpose | |---------|---------| | VTE prophylaxis | High risk - LMWH | | Steroids | Dexamethasone 16mg pre-op, taper post-op | | Analgesia | WHO ladder, may need neuropathic agents | | Rehabilitation | Inpatient rehab, mobility, ADL training | | Nutrition | Dietitian, may need supplementation | **Multidisciplinary Team:** - Orthopaedic/neurosurgeon - Medical oncologist - Radiation oncologist - Palliative care - Physiotherapy/OT - Cancer nurse coordinator > **Consultant Tip:** Dexamethasone 16mg immediately when MESCC diagnosed - reduces oedema and can stabilise or improve neurology before surgery. **Prognosis by Primary Tumour:** | Primary | Median Survival with Bone Mets | |---------|-------------------------------| | Thyroid | 48 months | | Prostate | 24 months | | Breast | 24 months | | Kidney | 12 months | | **Lung** | **3-6 months** | | Unknown | 3 months | **This Patient's Prognosis:** - Lung primary with multiple bone metastases - Tokuhashi score 5 → <6 months expected survival - Despite poor prognosis, surgery is indicated to preserve function **Counselling Points:** | Topic | Discussion | |-------|------------| | **Prognosis** | Honest discussion - months not years expected | | **Goals of surgery** | Preserve walking, bladder/bowel function, reduce pain | | **Not curative** | Surgery controls local disease, doesn't cure cancer | | **Risks** | Infection, bleeding, neurological injury, non-union | | **Rehabilitation** | Will need intensive physiotherapy | | **Quality of life** | Aim is to maximise function for remaining time | | **Advance care planning** | Consider goals of care, resuscitation status | **What to Tell the Patient:** "You have cancer that has spread to your spine and is pressing on your spinal cord. Without treatment, you will likely become paralysed. We recommend surgery to relieve the pressure and stabilise your spine, followed by radiotherapy. This won't cure the cancer, but it gives you the best chance of continuing to walk and maintaining bladder and bowel function. The recovery will take several weeks, and you'll need rehabilitation. We'll also work with the cancer doctors to see what other treatments might help." > **Consultant Tip:** Even with 3-6 month prognosis, preserving the ability to walk transforms quality of remaining life. A mobile patient can go home; a paralysed patient dies in hospital. --- ## Key Teaching Points ### Pattern Recognition **This pattern suggests Metastatic Spinal Cord Compression:** - Older patient with progressive back pain - Constitutional symptoms (weight loss, fatigue) - Smoking history (lung cancer risk) - Progressive neurological symptoms - Upper motor neuron signs (hyperreflexia, Babinski) - Sensory level on examination **Red Flags for Spinal Cord Compression:** - New back pain in known malignancy - Progressive weakness (hours to days) - Bladder/bowel dysfunction - Sensory level - Band-like chest/abdominal pain ### Critical Management Points 1. **This is an emergency** - deteriorating neurology requires urgent action 2. **Dexamethasone 16mg** immediately on diagnosis 3. **MRI whole spine** - 30% have multiple levels involved 4. **SINS score** guides mechanical stability 5. **Tokuhashi score** guides prognosis and surgical extent 6. **Surgery + RT** superior to RT alone (Patchell trial) 7. **Preserve ambulation** - non-ambulatory patients rarely walk again --- ## Common Examiner Follow-ups **Q: "What is the NOMS framework?"** NOMS is a decision framework for metastatic spine disease: | Component | Consideration | |-----------|---------------| | **N**eurological | Degree of cord compression, myelopathy | | **O**ncological | Radiosensitivity, systemic disease control | | **M**echanical | Stability (SINS score) | | **S**ystemic | Medical fitness, expected survival | It guides treatment selection: - High-grade compression + instability → Surgery + RT - Low-grade compression + stable + radiosensitive → RT alone - Unstable + radiosensitive → Surgery for stabilisation + RT --- **Q: "When would you consider stereotactic body radiotherapy (SBRT)?"** SBRT considerations: | Indication | Rationale | |------------|-----------| | Radioresistant tumour (RCC, melanoma) | Higher doses overcome resistance | | Oligometastatic disease | Potentially curative | | Re-irradiation | Can treat previously irradiated areas | | Post-operative | Better local control after separation surgery | Contraindications: - Spinal cord directly abutting tumour (need separation surgery first) - Multiple contiguous levels - Poor expected survival (<3 months) --- **Q: "What is separation surgery?"** Separation surgery is a minimally invasive approach: - Goal: Create gap between tumour and spinal cord - Decompress cord circumferentially - Stabilise with instrumentation - Allows safe delivery of SBRT post-operatively - Not attempting gross total resection - Reduces surgical morbidity while enabling high-dose RT --- **Q: "What is the role of vertebroplasty/kyphoplasty?"** Cement augmentation: | Indication | Use | |------------|-----| | Painful vertebral metastasis | Pain relief | | Prophylactic stabilisation | Prevent collapse | | Augment pedicle screws | Improve fixation in poor bone | **NOT indicated:** - Epidural tumour extension (cord compression risk) - Vertebral body posterior wall breach - Neurological compromise - Infection For this patient with cord compression, open surgery is required - vertebroplasty alone is contraindicated. --- ## Related Topics - Metastatic Bone Disease - Spinal Tumours - Pathological Fractures - Posterior Spinal Instrumentation - Radiotherapy in Oncology - Palliative Orthopaedics