Neurosurgery notes/Spine/Spinal tumours/Spinal metastatic tumours/Metastatic spinal tumours cord compression (MSCC)- Bony spinal metastasis/Management of MSCC/MSCC Radiotherapy

MSCC Radiotherapy

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Management of MSCC
  • Indication
    • For MSCC-NICE
      • Fractionated RTx in patients with epidural mets without neurology, mechanical pain or instability
      • Offer patients with spinal metastases causing non-mechanical spinal pain 8 Gy single fraction palliative radiotherapy even if they are completely paralysed.
      • Contraindication
        • Asymptomatic spinal metastases should not be offered RT with the intention of preventing MSCC except as part of a RCT.
      • Must have a cancer diagnosis before RT can start
    • MSCC + not suitable for surgery, urgent radiotherapy should be offered (< 24 h)
      • unless
        • complete tetraplegia or paraplegia for >24 h + pain well controlled
        • overall poor prognosis
    • Pre or post op
      • Preoperative radiotherapy should not be carried out on patients with MSCC if surgery is planned
        • Some surgeons do allow pre op radiotherapy if for example pt had a planned RT but post RT deteriorate with evidence of instability or MSCC requiring surgery
      • postoperative fractionated radiotherapy should be offered routinely to all patients with a satisfactory surgical outcome once the wound has healed.
  • Relative CI
    • No histological diagnosis of cancer
    • Radio-resistant tumor if surgery is an option (renal cell carcinoma, sarcoma, melanoma etc.)
      • NOMS suggest using SRS
    • Vertebral displacement/spinal instability,
    • Poor general condition (irreversible) due to co-morbidities,
    • Previous radiotherapy (to cord tolerance) to same spinal site
  • Dosage
    • Multiple fractions
      • 5 fraction vs 10 fraction (30 Gy total) Patchell=3x10Gy
        • no difference in motor improvements or overall survival
    • Single fractions
      • Single vs 5 fraction
        • Single is no difference than 5 fraction
      • Prognostic
        • Age
        • Performance status
        • Tokouhasi
        • Primary tumour
        • Number of vertebral involved
        • Time to MMSC from diagnosis
    • Spinal cord myelopathy risk (2Gy per fraction)
      • Do not go above 50 gy
    • Retreatments
      • less than 60 gy
  • Two types
    • Conventional External Beam Radiation Therapy cEBRT was the standard treatment.
      • Accurate delineation of the critical structures such as the spinal cord and nerve roots/plexuses as avoidance structures for treatment planning is paramount.
    • Stereotactic body Radiotherapy (SBRT) can deliver ablative dose while sparing the cord
      • SBRT delivers ablative doses of radiation to a target volume using advanced radiotherapy techniques
      • it is possible to deliver a much higher dose of radiation to a target volume in the spine without causing a high risk of radiation myelopathy (>10 Gy per fraction)
      • Stereotactic Ablative Body Radiotherayy
        • 24Gy/2 - 30Gy/3
        • for oligometastatic disease
          • only one or two mets that can be tx more aggressively
        • no role for unstable spine as it can make it more unstable
          • vertebral compression fracture 11-30%
          • 3% only for conventional radiotherapy
  • Effectiveness of radiotherapy
    • Radiotherapy is efficacious in the treatment of MSCC and, for example, in one large study (Maranzano and Latini, 1995), all but 2 of 109 walkers retained the ability and of 82 patients who had lost the ability to walk but had some preserved power, 60% recovered ambulation.
    • See Evidence surgery vs radiotherapy
  • Complications
    • Radiation myelopathy may present as a transient or irreversible.
      • Transient (acute) radiation myelopathy
        • Clinically manifested by Lhermitte’s sign
        • Developing 3-4 months after treatment
        • Spontaneously resolves over the following 3-6 months without therapy.
      • Irreversible radiation myelopathy
        • usually is not seen earlier than 6-12 months after completion of treatment.
          • 50% who develop radiation-induced myelopathy in the cervical or thoracic cord region will do so within 20 months of treatment
          • 75% of cases will occur within 30 months.
        • Clinical features
          • Typically progressive over several months
          • Can have acute onset of plegia over several hours or a few days is possible.
        • Pathophysiology
          • Multifactorial
          • Demyelination + white matter necrosis → oligodendroglial cell depletion + microvascular injury.
        • It is a diagnosis of exclusion with the following characteristics:
          • History of radiation therapy in doses sufficient to result in injury must be present
          • The region of the irradiated cord must lie slightly above the dermatome level of expression of the lesion
          • The latent period from the completion of treatment to the onset of injury must be consistent with that observed in radiation myelopathy
          • Local tumor progression must be ruled out.
        • Outcome
          • The probability of dying from radiation myelopathy is
            • 70% with cervical lesions
            • 30% with thoracic spinal cord injury.
    • Radiation side effects in children
      • Growth abnormalities such as
        • Decreased vertebral height
        • Kyphosis
        • Scoliosis
      • Secondary malignant disease after irradiation of spinal cord tumours:
        • Bone or soft-tissue sarcomas and glioblastoma