Background: To compare iodine-125 ( 125 I) with ruthenium-106 ( 106 Ru) episcleral plaque radiation therapy in terms of the effectiveness and non-inferiority for choroidal melanoma treatment.Objective: To report the non-inferiority of new made iodine-125 ( 125 I) compared with ruthenium-106 ( 106 Ru) episcleral plaque radiation. Patients and Methods: A retrospective, non-randomized comparative case series. In this series the patients treated with 125 I and 106 Ru episcleral plaques for choroidal melanoma between September 2013 and August 2017 at Farabi Hospital are compared. Local control of choroidal melanomas after 125 I and 106 Ru plaques implantation and vision changes are the main outcome measures. Results: A total of 35 patients were identified ( 125 I = 15, 106 Ru = 20). No significant difference between two groups in visual acuity, diameter and thickness changes were observed after treatment. Multivariate linear regression (MLR) analysis showed that final diameter was only, independently and significantly, correlated with the pre-treatment diameter of the tumor (β = 0.59, 95% confidence interval [CI]: 0.29, 1.34, P = 0.003). The same MLR analysis for the final thickness and visual acuity, after adjusting for age and sex showed no significant difference between two groups. A single patient treated with 106 Ru had local tumor recurrence with no one in the 125 I group. No statistical difference in the rate of ocular complications was observed. Conclusion: The treatment with our 125 I plaques is as effective as 106 Ru plaques in controlling choroidal melanoma tumor and preserving the vision during the two and half year of follow-up. The complication rates are alike. It means that the effectiveness of 125 I is not only comparable to 106 Ru but also superior when the outcome of the interest is the thickness of the tumors.

Background To assess the impact of brachytherapy on macular microvasculature utilizing optical coherence tomography angiography (OCTA) in treated choroidal melanoma. Methods In this retrospective observational case series, we reviewed the recorded data of the patients with unilateral extramacular choroidal melanoma treated with ruthenium − 106 (106Ru) plaque radiotherapy with a follow-up period of more than 6 months. Automatically measured OCTA retinal parameters were analysed after image processing. Results Thirty-one eyes of 31 patients with the mean age of 51.1 years were recruited. Six eyes had no radiation maculopathy (RM). From 25 eyes with RM, nine eyes (36%) revealed a burnout macular microvasculature with imperceptible vascular details. Twenty-one non-irradiated fellow eyes from the enrolled patients were considered as the control group. Foveal and optic disc radiation dose had the highest value to predict the burnout pattern (ROC, AUC: 0.763, 0.727). Superficial and deep foveal avascular zone (FAZ) were larger in irradiated eyes in comparison to non-irradiated fellow eyes (1629 μm2 vs. 428 μm2, P = 0.005; 1837 μm2 vs 268 μm2, P = 0.021; respectively). Foveal and parafoveal vascular area density (VAD) and vascular skeleton density (VSD) in both superficial and deep capillary plexus (SCP and DCP) were decreased in all irradiated eyes in comparison with non-irradiated fellow eyes (P < 0.001). Compared with non-irradiated fellow eyes, irradiated eyes without RM had significantly lower VAD and VSD at foveal and parafoveal DCP (all P < 0.02). However, these differences at SCP were not statistically significant. Conclusion The OCTA is a valuable tool for evaluating RM. Initial subclinical microvascular insult after 106Ru brachytherapy is more likely to occur in DCP. The deep FAZ area was identified as a more critical biomarker of BCVA than superficial FAZ in these patients.

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