12-phase flow (12)

1. 1FRAME
   Adult cancer patient with new spine pain, motor deficit, sensory level, or sphincter dysfunction → suspect MSCC; time-critical oncologic emergency (Cole-Patchell Lancet Neurol 2008 PMID 18420159)
   advance: MSCC suspected on clinical grounds; STAT MRI mobilised
2. 2ENTRY
   Capture entry trigger (new back pain in cancer patient, motor deficit, sensory level, sphincter); time of onset of motor symptoms (treatment-window driver)
   inputs: age, duration_of_motor_deficit_before_presentation
   advance: Entry phenotype assigned + STAT MRI ordered + dexamethasone bolus given
3. 3CONTEXT
   Capture primary tumour histology + extent of metastatic disease + performance status + prior RT + anticoagulant exposure + analgesic regimen (Laufer Oncologist 2013 PMID 23709750)
   inputs: primary_tumour_histology, performance_status_ecog_karnofsky, systemic_disease_burden
   advance: Context captured; oncology + neurosurgery + radiation-oncology MDM initiated within 24 h
4. 4RED_FLAGS
   Critical triggers — rapidly progressive motor deficit, sensory level, sphincter dysfunction, mechanical instability (SINS ≥7), bilateral cord signs, complete cord syndrome — STAT MRI + steroid + neurosurgery consult (Loblaw 2012 PMID 22420969)
   inputs: duration_of_motor_deficit_before_presentation, ambulatory_status_at_presentation
   actions: workup.spinal_cord_compression
   advance: Red-flag triage complete; emergent imaging + steroid + consults dispositioned
5. 5INITIAL_WORKUP
   STAT MRI WHOLE SPINE with gad (multifocal in ≈30% — never just the symptomatic level); CT for SINS bony assessment; CBC + CMP + LFT + coag + CRP/ESR (rule out infection); ECG + chest x-ray as pre-op baseline (Loblaw 2012 PMID 22420969; NICE CG75/NG41)
   inputs: mri_whole_spine_with_gad, ct_spine_for_sins_bony_assessment, cbc_cmp_lft_inr_aptt, inflammation_crp_pct_esr
   actions: workup.spinal_cord_compression, panel.cbc, panel.renal, panel.lft, panel.coag, panel.inflammation, panel.cardiac
   advance: MRI whole-spine + CT complete; level of compression + ESCC grade + SINS documented
6. 6BRANCHING_WORKUP
   If unknown primary → tumour-marker panel + age-appropriate screening + biopsy (CT-guided or open). If known primary → restaging CT/PET. Bone scan for polyostotic burden. Anti-resorptive evaluation (denosumab vs zoledronic acid). Prior-RT records for re-irradiation planning (Laufer J Neurosurg Spine 2013 PMID 23339593)
   inputs: prior_radiotherapy_to_same_level
   advance: Histology + extent + prior-RT status documented; biopsy planned if unknown primary
7. 7DIFFERENTIAL
   Phenotype — radiosensitive (breast / prostate / myeloma / lymphoma / SCLC) vs radioresistant (NSCLC / RCC / melanoma / sarcoma / colorectal / hepatocellular); polyostotic vs isolated; mechanical-instability axis (SINS); life-expectancy axis (>3 mo vs <3 mo; Tokuhashi schema-blocked). DDx: spinal epidural abscess (id pivot — fever + CRP↑↑↑), epidural hematoma, traumatic compression, transverse myelitis, osteoporotic compression fracture, discitis-osteomyelitis (Cole-Patchell PMID 18420159; MacLean Lancet Oncol 2022 PMID 35772464)
   inputs: primary_tumour_histology
   advance: NOMS axes (N/O/M/S) populated; treatment pathway selected
8. 8RISK_STRATIFICATION
   Ambulation at presentation (best prognostic factor; Patchell PMID 16112300); ECOG/Karnofsky; life-expectancy estimate. Schema-blocked: calc.sins + calc.tokuhashi + calc.tomita not registered — encoded narratively in severity_triggers. NIHSS NOT validated for cord syndromes (use ASIA grade clinically)
   inputs: ambulatory_status_at_presentation, performance_status_ecog_karnofsky
   advance: Severity tier + prognostic-band assigned; MDM decision documented
9. 9TREATMENT
   STEP-1: dexamethasone bolus IMMEDIATELY on clinical suspicion (do NOT wait for MRI). High-dose (96 mg IV bolus then 96 mg/d × 3 d then taper per Sørensen Eur J Cancer 1994 PMID 8142159) if severe deficit; standard (10 mg IV bolus then 16 mg/d in divided doses) for mild-moderate per Loblaw 2012 PMID 22420969. STEP-2: NOMS-driven decision — surgery + RT (Patchell Lancet 2005 PMID 16112300; better ambulation 84% vs 57%) for radioresistant + mechanical-instability + life-expectancy >3 mo + single-level disease; RT alone for radiosensitive + ambulatory + good life-expectancy (8 Gy single-fraction per Hoskin SCORAD JAMA 2019 PMID 31794625 for short life-expectancy; 30 Gy/10 or 20 Gy/5 for longer life-expectancy); SBRT for radioresistant + isolated lesion + good life-expectancy (Laufer J Neurosurg Spine 2013 PMID 23339593). STEP-3: bisphosphonate / denosumab for systemic bone-targeting (cross-link). STEP-4: analgesia — WHO ladder + opioid; gabapentinoid for neuropathic component
   inputs: primary_tumour_histology, ambulatory_status_at_presentation
   actions: workup.spinal_cord_compression, panel.cardiac
   advance: Steroid given + RT/surgery decision documented + analgesia titrated
10. 10DISPOSITION
    Inpatient admission for STAT MRI + RT/surgery + rehab; if RT-only ambulatory with good support — outpatient RT possible after first dexamethasone + first fraction (NICE NG41). Transfer to surgical centre if NSurg unavailable (Loblaw 2012 PMID 22420969)
    advance: Disposition + transfers arranged
11. 11MONITORING
    Daily neuro exam + ambulation + sensory level + sphincter function during admission; pain score; steroid side-effects (glucose, gastric, mood, sleep); bone-mineral burden; secondary VTE prophylaxis (LMWH 24-48 h post-decompression). Repeat MRI at 3 mo + as clinically indicated (Loblaw 2012 PMID 22420969)
    advance: Monitoring schedule documented
12. 12FOLLOWUP
    Outpatient oncology + radiation oncology + neurosurgery (if operated) + rehab; PHQ-9 depression screen (post-MSCC depression high); bowel/bladder management; recurrence-symptom education; anti-resorptive therapy ongoing; advance-care-planning discussion (life-expectancy is the dominant prognostic factor)
    advance: Long-term plan + specialty referrals + ACP scheduled