Early Peripapillary and Macular Microvascular Changes Following Ruthenium-106 Plaque Brachytherapy For Uveal...

Area of Science:

• Ophthalmology
• Radiation Oncology
• Medical Imaging

Background:

• Uveal melanoma is the most common primary intraocular malignancy.
• Ruthenium-106 (Ru-106) episcleral plaque brachytherapy is a standard treatment for uveal melanoma.
• Assessing treatment-induced microvascular changes is crucial for understanding visual outcomes.

Purpose of the Study:

• To evaluate early peripapillary and macular microvascular changes after Ru-106 brachytherapy for uveal melanoma.
• To assess the utility of optical coherence tomography angiography (OCTA) in detecting these changes.
• To correlate microvascular changes with radiation dose and visual acuity.

Main Methods:

• Prospective case series of 24 patients with uveal melanoma treated with Ru-106 brachytherapy.
• Ophthalmic evaluation and OCTA imaging performed at baseline, 3 months, and 6 months post-treatment.
• Quantitative OCTA parameters (vessel density in superficial, deep, and radial peripapillary capillary plexuses; foveal avascular zone area) were analyzed.

Main Results:

• Best-corrected visual acuity declined significantly at 6 months (p=0.028).
• Radial peripapillary capillary density showed early significant reduction (p<0.001), correlating with optic nerve radiation dose and visual decline.
• Deep capillary plexus density declined progressively, with significant foveal avascular zone enlargement (p<0.001).
• Tumor location influenced vascular response patterns.

Conclusions:

• Ru-106 brachytherapy induces early, subclinical microvascular injury detectable by OCTA.
• OCTA can identify distinct patterns of vascular damage (RPC, SCP, DCP) related to radiation dose and tumor location.
• OCTA serves as a potential noninvasive biomarker for early detection and risk stratification of radiation-induced microvascular injury.