Radiation Oncology/Head & Neck/Sinonasal/Ethmoid sinuses

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Ethmoid cancer

Risk factors[edit]

  • Occupational
    • Sawdust, cement dust - ethmoid adenocarcinoma
    • Exposure to thoratrast, nickel, cadmium, formaldehyde
  • Pollution
  • Smoking
  • HPV (SCC)
  • ?chronic sinusitis

Pathology[edit]

  • SCC most common
  • Mucoepidermoid
  • Adenoid cystic
  • Adenocarcinoma
  • Rare:
    • Olfactory neuroblastomas (esthesioneuroblastoma)
    • Angiosarcoma
    • Rhabdomyosarcoma
    • Lymphoma

Natural history[edit]

  • Usually well differentiated, slow growing
  • Present due to local invasion beyond sinus although can sometimes present due to sinusitis or nasal obstruction
  • Tumours commonly invade through bone - through cribriform plate to anterior cranial fossa, or lamina papyracea to orbit

Route of spread[edit]

  • Primarily through local invasion; nodal metastases are uncommon (< 20%, even lower for adenoid cystic)
  • Nodal involvement is more common when there is extension into surrounding tissues
  • Sinuses themselves are lymphatic poor
  • First echelon lymph nodes are retropharyngeal

Presentation[edit]

  • Facial or nasal pain
  • Epistaxis
  • Sinus obstruction
  • Trismus (pterygoid involvement)
  • Ocular symptoms: diplopia, visual disturbance, proptosis
  • Neural involvement eg trigeminal neuralgia

Staging[edit]

See Staging

Outcomes[edit]

  • Local control 50-60%
  • Overall survival 30-50% at 5 years

Management[edit]

  • Most evidence is via retrospective single institution reports
  • Options:
    • Surgery (eg craniofacial resection, orbital exenteration)
      • Often difficult as locally advanced by the time of presentation
      • May include orbital exenteration if there is orbital invasion
    • Radiotherapy
      • Unclear whether preop or postop RT is better
        • Preop chemoRT may improve resectability
      • Adjuvant treatment does appear to increase local control although there exists no randomised data to confirm this
      • Radiotherapy as definitive management is most appropriate
        • Difficult resection anatomically
        • Dose 70Gy definitive, with chemotherapy for advanced lesions
        • Comprehensive nodal irradiation (retropharyngeal nodes) only if node positive or extrasinus involvement (skin, muscle)
        • Dose limiting structures
          • Eye, optic chiasm
          • Brain
        • Technique
          • Ant and wedged laterals (posterior to eye)
          • Treat neck nodes prophylactically if there is skin/muscle involvement otherwise target volume is antrum alone