Visual acuity, oncologic, and toxicity outcomes with 103Pd vs. 125I plaque treatment for choroidal melanoma

PURPOSE: To evaluate outcomes of choroidal melanoma patients treated with I-125 or Pd-103 plaque brachytherapy. METHODS AND MATERIALS: From 1993 to 2012, our institution treated 160 patients with Pd-103 (56.1%) and 125 patients with I-125 (43.9%) plaque brachytherapy. Tumor outcomes, visual acuity (VA), and toxicity were compared. Multivariate analyses (MVAs) and propensity score analysis were used to help address differences in baseline characteristics. RESULTS: Median followup was longer for I-125 patients, 52.7 vs. 43.5 months (p < 0.01). At baseline, Pd-103 patients had lower rates of VA worse than 20/200 (4.4% vs. 16%, p = 0.002), T3-T4 tumors (17.5% vs. 32.8%, p = 0.03), and transpupillary thermotherapy use (3.1% vs. 9.6%, p = 0.001). Both Pd-103 and I-125 provided >90% 3-year overall survival and >93% 5-year secondary enucleation-free survival. On MVA, radionuclide was not predictive for tumor outcomes. A higher percentage maintained vision better than 20/40 with (103)d (63% vs. 35%, p = 0.007) at 3 years. MVA demonstrated (103)d radionuclide (odds ratio [OR]: 2.12, p = 0.028) and tumor height mm (OR: 2.78, p = 0.017) were associated with VA better than 20/40. Propensity score analysis matched 23 I-125 with 107 Pd-103 patients. Pd-103 continued to predict better VA at 3 years (OR: 8.10, p = 0.014). On MVA for the development of VA worse than 20/200 or degree of vision loss, radionuclide was not significant. Lower rates of radiation retinopathy were seen with (103)d than I-125 (3 years: 47.3% vs. 63.9%, p = 0.016), with radionuclide significant in MVA. CONCLUSIONS: Both I-125 and Pd-103 achieve excellent tumor control. An increased probability of long-term VA better than 20/40 and reduced risk of radiation retinopathy is associated with (103)p (C) 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.