Reese - Ellsworth classification for intraocular tumours

Developed in the 1960s this classification isused when surgery and external-beam radiation therapy (EBRT) were the primary treatment options (1).

• is used to predict the outcome in patients who were treated with EBRT (2)
• this system is based on number, size and location of tumours and the presence of vitreous seeding (1)

The classification system has five groups:

• Group I: very favourable prognosis
  • A: Solitary tumour, smaller than 4 disc diameters in size, at or behind the equator
  • B: Multiple tumours, none greater than 4 disc diameters in size, all at or behind the equator
    
    
• Group II: favourable prognosis
  • A: Solitary tumour, 4–10 disc diameters in size, at or behind the equator
  • B: Multiple tumours, 4–10 disc diameters in size, all at or behind the equator
    
    
• Group III: doubtful prognosis
  • A: Any lesion anterior to the equator
  • B: Solitary tumour, larger than 10 disc diameter, behind the equator
    
    
• Group IV: unfavourable prognosis
  • A: Multiple tumours, some greater than 10 disc diameters
  • B: Any lesion extending anteriorly to the ora serrata
    
    
• Group V: very unfavourable prognosis
  • A: Massive tumours involving more than half of the retina
  • B: Vitreous seeding (3)

With the introduction of newer treatment modalities (e.g. - chemotherapy) which have replaced EBRT, the usefulness of this classification system is less apparent (2).

Reference:

• (1) National Cancer Institute 2012. Retinoblastoma treatment
• (2) Chintagumpala M et al. Retinoblastoma: review of current management. Oncologist. 2007;12(10):1237-46
• (3) McDaid C et al. Systematic review of effectiveness of different treatments for childhood retinoblastoma. Health Technol Assess. 2005;9(48):iii, ix-x, 1-145.