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

Abstract

PURPOSE To evaluate outcomes of choroidal melanoma patients treated with 125I or 103Pd plaque brachytherapy. METHODS AND MATERIALS From 1993 to 2012, our institution treated 160 patients with 103Pd (56.1%) and 125 patients with 125I (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 125I patients, 52.7 vs. 43.5 months (p < 0.01). At baseline, 103Pd 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 103Pd and 125I 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 103Pd (63% vs. 35%, p = 0.007) at 3 years. MVA demonstrated 103Pd radionuclide (odds ratio [OR]: 2.12, p = 0.028) and tumor height ≤5 mm (OR: 2.78, p = 0.017) were associated with VA better than 20/40. Propensity score analysis matched 23 125I with 107 103Pd patients. 103Pd 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 103Pd than 125I (3 years: 47.3% vs. 63.9%, p = 0.016), with radionuclide significant in MVA. CONCLUSIONS Both 125I and 103Pd achieve excellent tumor control. An increased probability of long-term VA better than 20/40 and reduced risk of radiation retinopathy is associated with 103Pd.

Monte Carlo study on the gold and gadolinium nanoparticles radio-sensitizer effect in the prostate 125I seeds radiotherapy

“…In the case of DEF of gold and gadolinium nano-particles in the brachytherapy, some paper has been published [3][4][5][6][7][8][9][10][11][12][13][14][15][16]. The studies show that for low energy sources, DEF of nanoparticles is higher than high energy sources.…”

“…Different brachytherapy sources with own design have been studied utilizing Monte Carlo (MC) simulation and experimentally by different dosimeters [1][2][3][4][5][6][7]. Among the sources, 125 I seed also has designed and used to cancerous tissue treatment [8][9][10][11][12]. Villagas et al [9] conducted a study to characterize the magnitude of the spread in specific energy deposition per cell and reported increasing in micro-dosimetric value with decreasing target size and decreasing energy of the radiation quality.…”

Regression patterns of choroidal melanoma: After palladium-103 (103Pd) plaque brachytherapy

“…In terms of visual acuity: Marconi et al 44 noted that after 106 Ru plaque brachytherapy, 56% of patients had visual acuity of 20/25 initially, out of which more than half stayed with 20/40. Patel et al 45 compared 103 Pd with 125 I and found that >20/40 visual acuity was noted in 65% with 103 Pd versus 30% with 125 I. Papakostas et al 46 noted visual acuity of ⩾20/200 in 8.7% patients and counting fingers in 22% patients after proton beam radiotherapy. In our study, we noted excellent median visual acuity of 20/32 with 103 Pd plaque brachytherapy.…”

Radiation therapy for uveal melanoma: a review of treatment methods available in 2021

“…Head-to-head studies between iodine-135 and palladium-103 plaque brachytherapies are limited but it appears plaque brachytherapy delivered by either isotope has excellent overall survival and globe salvage rates. palladium-103 may demonstrate lower rates of radiation retinopathy [88]. In theoretical models using COMS plaques, cesium-131 may have the most uniform dose distribution but cesium plaque brachytherapy remains relatively uncommon [89].…”