Survival and complications following Gamma Knife radiosurgery or enucleation for ocular melanoma: a 20-year experience.Eduard B. Dinca1, Daniel Preotiuc-Pietro2, John Yianni3, Matthias W.R. Radatz3, Jeremy Rowe1, Paul Rundle4, Andras A. Kemeny31Sheffield, United Kingdom 2Department of Computer Sciences, University of Sheffield, UK 3The National Centre for Stereotactic Radiosurgery, Sheffield, UK 4Department of Ophtalmology, Royal Hallamshire Hospital, Sheffield, UK Keywords: melanoma, orbit, gamma knife, vision, outcome
Ocular melanoma presents distinct treatment challenges.
We present our experience in treating ocular melanoma at the National Centre for Stereotactic Radiosurgery in Sheffield, UK over the last 20 years.
We analyzed 170 ocular melanoma patients treated with Gamma Knife radiosurgery.
We recorded the evolution of visual acuity and complication rates in 170 patients after radiosurgery, and compared their survival with 620 patients treated with eye enucleation. Different peripheral doses (using the 50% therapeutic isodose) were employed: 50-70Gy in 24 patients; 45Gy in 71 patients; 35Gy in 62 patients.
The 5-year survival rates for each group were: 64% for 35Gy, 62.71% for 45Gy, 63.6% for 50-70Gy, and 65.2% for enucleated patients. There was no significant difference in survival between the 35, 45 and 50-70Gy groups when compared between themselves (p=0.168) and with the enucleation group (p=0.454). Clinical variables influencing survival for radiosurgery patients were tumour volume (p=0.014) and location (median 66.4 vs. 37.36 months for juxtapapillary vs. peripheral tumours, respectively; p=0.001) while age and gender did not prove significant. Using 35Gy led to more than 50% decrease in the incidence of cataract, glaucoma and retinal detachment, when compared to the 45Gy dose. Retinopathy, optic neuropathy and vitreous haemorrhage were not significantly influenced. Blindness decreased dramatically from 83.7% for 45Gy to 31.4% for 35Gy (p=0.006), as did post-radiosurgery enucleation: 23.9% for 45Gy vs. 6.45% for 35Gy (p=0.018). Visual acuity, recorded up to 5 years post-radiosurgery, was significantly better preserved for 35Gy than for 45Gy (p=0.0003).
This was a retrospective study but with a case-control group.
Using a therapeutic dose of 35Gy led to a dramatic decrease in complications, vision loss and salvage enucleation, while not compromising patient survival.
Gamma knife radiosurgery can be effective for ocular melanoma and is an alternative to enucleation. Project Roles:
E. Dinca (), D. Preotiuc-Pietro (), J. Yianni (), M. Radatz (), J. Rowe (), P. Rundle (), A. Kemeny ()