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Radiodermites

Mecanismo
  • Radiação ionizante → excitação e ionização dos tecidos → destruição dos tecidos
    • Inflammation
    • Vasodilation
    • Edema
    • Cell growth arrest
  • Células diferenciadas da epiderme são resistentes à radiação. Mas as células estaminais a multiplicar-se da camada basal são danificadas
    • Por isso, os sintomas só surgem 15-20 dias depois da irradiação, quando as células basais progridem para o estrato córneo
    • Isto difere da radiação ultravioleta, em que também as células diferenciadas são afetadas, levando a sintomas mais precoces
 
Severity depends on
  • Dose
  • Extent or area
  • Time or duration
  • Fraccionation
  • Nature of the beam (photons, electrons)
 
Fatores de risco
  • Medicamentos fotossensibilizantes
      • Medicamentos fotossensibilizantes - com estrutura química em anel
        • tetracyclines: Doxiciclina, minociclina
        • Quinolonas,
        • NSAIDs especially propionic acid derivatives
          • Ibuprofen, naproxen, cetoprofen
        • Thiazide diuretics,
        • Amiodarone,
        • Voriconazole → chronic photosensitivity iduced by coriconazole, often prescribed for long periods in immunocompromised patients, leads to skin aging with makor heliodermatosis and aggressive squamous cell carcinomas
        • Photoallergic reactions
        • Chlorpromazine,
        • Vemurafenib
  • Concomitant cytostatic chemotherapy, targeted therapies (EGFR)
  • Advanced age, comorbidities (diabetes, HIV), smoking, malnutrition
  • Prior damage to the skin
  • Certain areas
    • Skin folds
    • Areas where skin is thin
 
Clinical presentation
  • Skin
    • Acute radiodermitis
      • Inflammation, vasodilations, edema, cell growth arrest
      • Grade I: erythema
        • After 9-20 days
        • May have burning sensation
        • Resolves with desquamation
      • Grade II: moderate erythema and edema
      • Grade III: exudative radiodermatitis
        • Blisters, oozing dermis
      • Grade IV: exudative radionecrosis
        • Very painful ulceration, can expose bone
    • Chronic radiodermitis
      • fibrosis of dermis
      • Thinning of epidermis
      • Radiodystrophy
      • Cancerization
        • Basal cell carcinoma
        • Pinkus fibroepithelial tumors
    • Dermatoses in areas treated with radiotherapy
      • Vitiligo
      • Bullous pemphigoid
 
Treatment
  • Acute radiodermatitis
    • Emollients for early acute radiodermatitis
    • Trolamine for erythematous radiodermatitis
    • Sucralfate
    • Topical corticosteroids in grade III and IV
  • Chronic radiodermatitis
    • Plastic surgery
    • Surgical excision of radiodystrophic area
    • Flaps, grafts
    • Lipofilling, lipostructure