Abstract
Purpose :
To find out the factors that determine the risk of radiation retinopathy development after Plaque radiation treatment.
Methods :
Retrospective analysis of all patients who underwent plaque brachytherapy with Iodine-125 for choroidal melanoma between 2004-2020 was done. Forty-eight patients who had minimum follow-up of 12 months post treatment were included in the analysis.
Results :
Thirty of the 48 patients developed radiation retinopathy (62.5%) of which 23 patients had non-proliferative retinopathy and 7 patients had proliferative retinopathy. Twenty-five (83.33%) of the 30 patients also developed radiation maculopathy. Kaplan Meir survival analysis showed that proportion of patients free from radiation retinopathy is 50% at 5 years and 20% at 10 years. On univariate analysis, risk factors predictive of radiation retinopathy included increased width of the tumour (Hazard ratio (HR)= 1.14191, p=0.038), surface area of the tumour (HR= 1.0082, p=0.0371), total radiation dose to the apex of the tumour (HR= 1.01413, p=0.0371) and radiation to the optic nerve head (HR=1.0056, p=0.0374). On multivariate analysis, total radiation to the optic nerve head was the best predictor of radiation retinopathy (HR=1.0056, p=0.0380). Risk factors predictive of radiation maculopathy included total radiation dose to the apex of tumour (HR= 1.0468, p=0.0357) and radiation to the optic nerve head (HR= 1.0069, p=0.0182) on univariate analysis and radiation dose to the apex of tumour (HR= 1.0486, p=0.0334) and radiation to the optic nerve head (HR= 1.0067, p=0.0159) on multivariate analysis also.
Eighteen of the 23 patients with radiation maculopathy were treated with Intravitreal-Anti VEGF injections and 1 patient received an intravitreal dexamethasone implant. A mean of 2.4 (Range 1-6) injections were given.
Conclusions :
Radiation retinopathy is a common complication of plaque brachytherapy for choroidal melanoma occurring in 50% of the patients at 5 years. The main predictive risk factors for development of radiation retinopathy in our study was total radiation dose to the apex, radiation to the optic nerve head as well as increased width and surface area of the tumour. All patients undergoing plaque brachytherapy for choroidal melanoma should be followed up closely for signs of radiation retinopathy.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.