Abstract
Introduction: :
External beam radiotherapy (EBRT) has been employed in retinoblastoma to save eyes with visual potential which have failed primary chemotherapy, and are unsuitable for focal salvage treatments. Radiation has been implicated in the induction of secondary malignancies in children with genetic retinoblastoma, and there is a need to determine whether this risk can be justified by the satisfactory rate of preservation of eyes with useful vision.
Purpose: :
To determine the rate of eye and vision preservation in patients with bilateral (genetic) retinoblastoma after salvage EBRT
Methods and Setting: :
Retrospective observational case series (1991–2004) at St. Bartholomew’s & Royal London Hospitals, UK.
Inclusion Criteria: :
Patients with bilateral retinoblastoma who had failed primary chemotherapy and focal salvage treatment, requiring EBRT.
Outcome measures: :
After EBRT: 1) Percentage of eyes retained 2) Percentage of eyes with extrafoveal tumours and no retinal detachment 3) Radiation–induced side effects.
Results: :
Thirty–four eyes (21 patients) were included. The median follow–up duration was 50 months (range 15–153 months) from diagnosis. Thirty eyes received lens–sparing radiotherapy, and 4 eyes received whole–eye radiotherapy. Five eyes failed EBRT and were enucleated at a mean interval of 19 months (range 9–36 months) after EBRT. The rate of eye preservation was 85.3% at a median follow–up of 3 years (range 5–150 months) after EBRT. Fourteen of these eyes (48.3%) had extrafoveal tumours without retinal detachment. Cataracts and keratoconjunctivitis sicca were observed in the 4 eyes which received whole–eye radiotherapy.
Conclusions: :
The rate of eye preservation 3 years after salvage EBRT in bilateral retinoblastoma is 85.3%, and 48.3% of the retained eyes had potential for central vision. Radiation–induced side effects were only observed with whole eye radiotherapy. This information will be significant in determining the justification of EBRT against local and long–term radiation–induced side effects when treating and counselling this cohort of patients.
Keywords: retinoblastoma • radiation therapy • oncology