Conformal Plaque Brachytherapy Outcomes for Peripapillary Choroidal Melanoma
Authors: Emily Xi Liao, Aqsa Saleem, Jordan Huang, Matthew Larocque, Geetha Menon, Albert Murtha, Ezekiel Weis.
Author Disclosure Block: E. Liao: None. A. Saleem: None. J. Huang: None. M. Larocque: None. G. Menon: None. A. Murtha: None. E. Weis: None.
Purpose: Uveal melanoma, the most common intra-ocular tumor and vision sparing treatment, comes with increased risk of local failure and radiation retinopathy. Treatment of peripapillary choroidal melanoma with plaque brachytherapy has historically demonstrated poor outcomes. To report on local treatment failure rate, survival rate, enucleation rate, and vision loss for patients with peripapillary, juxtapapillary, and circumpapillary choroidal melanoma treated with conformal plaque brachytherapy (CPB).
Study Design: This ethics approved study included a prospective case series of patients with peripapillary, juxtapapillary and circumpapillary choroidal melanoma treated with CPB.
Methods: Patients with peripapillary choroidal melanoma treated with Iodine-125 (125I) plaque brachytherapy between Oct 2011 to May 2021 in Alberta, Canada were enrolled. Outcomes assessed included local treatment failure rate, survival rate, enucleation rate and visual acuity.
Results: In total, 158 patients were treated with plaque brachytherapy. We reviewed 51 patients with peripapillary (1.1 mm - 2.0 mm from optic disc), 50 juxtapapillary (0.1mm - 1.0 mm from the optic disc) and 57 circumpapillary (0 mm from the optic disc) choroidal melanomas. The mean age was 63.7 ± 15.8 years. The overall survival rate for peripapillary, juxtapapillary and circumpapillary choroidal melanoma patients are 46/51 (90.2%), 40/50 (80.0%) and 52/57 (91.2%) respectively, at a mean follow-up of 3.6 ± 2.5 years. Both the local treatment failure rate and enucleation rate was 1/158 (0.6%) (both for circumpapillary 1/50 (2.0%)). Vision was better than 20/200 in 50%. Univariate logistic regression demonstrated tumor height, macular dose, and dose rate to be related to poor visual acuity (<20/200 vision). Multivariate regression demonstrated tumor height and macular dose to be the only statistically significant predictors of poor visual acuity.
Conclusions: Conformal plaque brachytherapy provided a local tumor control and eye preservation rate of 99.4% for patients with peripapillary, juxtapapillary, and circumpapillary choroidal melanoma at a mean follow-up of 3.6 ± 2.5 years. The mean survival rate was 87.1% for all three groups, which is comparable to the survival rate reported for other treatment methods, including external beam radiotherapy and nucleation. CPB provides an effective eye preserving alternative treatment in these cases.