Deterioration of Visual Acuity after Brachytherapy and Proton Therapy of Uveal Melanoma, and Methods of Counteracting This Complication Based on Recent Publications

Functional outcome after Brachytherapy with bi-nuclide (Ru-106/Iodine-125) plaques in large uveal melanomas

OBJECTIVE

Preservation of visual acuity remains a challenging issue after globe sparing therapy of large uveal melanoma. The aim of our study was analyzing the functional outcome after brachytherapy with bi-nuclide plaques (BBNP), maintaining prognostic factors for legal blindness (LB).

METHODS

We have analyzed all consecutive patients with large uveal melanoma treated with BBNP at our institution between 01/1999 and 12/2020. The post-treatment follow-up data were screened up to 06/2023. Univariate and multivariate Cox regression analysis was performed to identify predictive factors for development of LB following BBNP.

RESULTS

Overall, 570 patients with median age of 65.6 years (interquartile range [IQR]: 54.5-74.0) underwent BBNP. During the median post-treatment follow-up of 30.8 months (IQR: 12.9-57.3), LB was diagnosed in 287 (50.4%) patients. Patients' age (> 67 years, adjusted hazard ratio [aHR] = 1.58, 95%-confidence interval [CI] = 1.24-2.00, p < 0.0001), tumor thickness (> 8.5 mm, aHR = 1.43, 95%-CI = 1.12-1.82, p = 0.004), VA (> 0.5 LogMAR, aHR = 1.59, 95%-CI = 1.25-2.02, p < 0.0001), and ciliary body involvement (aHR = 0.77, 95%-CI = 0.60-0.97, p = 0.029) were confirmed as independent predictors of LB in the final multivariable Cox regression analysis.

CONCLUSIONS

Approximately a half of patients with large uveal melanoma develop LB around 2.5 years after brachytherapy. Further optimization of treatment strategies, including both therapeutic and preventive measures, has the potential to enhance the functional outcome after episcleral plaque therapy for large UMs.

Cataract Extraction After Brachytherapy for Malignant Melanoma of the Choroid in a Young Female Patient: A Case Report

The use of brachytherapy, a form of radiation therapy, plays a crucial role in the management of intraocular melanomas of the choroid. Ionization radiation treatment has the unfortunate side effect of developing cataracts prematurely. We present an uncommonly seen case of a 36-year-old woman who presented with blurred vision in her left eye following successful plaque radiotherapy four years prior for malignant melanoma in the same eye. The patient had developed a cataract, which hindered her visual acuity and visualization of the tumor. Prompt cataract surgery after brachytherapy for radiation-induced cataracts is necessary for the improvement of the quality of life and ensuring effective uveal and retinal examination.

Pan-Cancer Analysis of PGAM1 and Its Experimental Validation in Uveal Melanoma Progression

Phosphoglycerate mutase 1 (PGAM1) is a key enzyme regulating cancer glycolysis. However, the expression and function of PGAM1 in uveal melanoma (UVM) are unknown and systematic analysis is lacking. This study performed a comprehensive analysis of PGAM1 expression across 33 cancer types in multiple public databases. Results demonstrated PGAM1 is aberrantly overexpressed in most tumors compared to normal tissues, and this overexpression is associated with poor prognosis, advanced tumor staging, and aggressive clinical phenotypes in multiple cancers including UVM, lung, breast and bladder carcinomas. In addition, PGAM1 expression positively correlated with infiltration levels of tumor-promoting immune cells including macrophages, NK cells, myeloid dendritic cells, etc. Further experiments showed that PGAM1 was overexpressed in UVM cell lines and tissues, and it was positively associated with a poor prognosis of UVM patients. And knockdown of PGAM1 inhibited migration/invasion and induced apoptosis in UVM cells, followed by decreased levels of PD-L1, Snail, and BCl-2 and increased levels of E-cadherin. Additionally, the correlation analysis and molecular docking results suggest that PGAM1 could interact with PD-L1, Snail and BCl-2. Thus, PGAM1 may promote UVM pathogenesis via modulating immune checkpoint signaling, EMT and apoptosis. Collectively, this study reveals PGAM1 as a valuable prognostic biomarker and potential therapeutic target in aggressive cancers including UVM.