Post-radiation macular edema after brachytherapy for choroidal melanoma (Ru/Rh106): risk factors and correction possibilities

Objective. To improve the immediate results of brachytherapy for choroidal melanoma by identifying risk factors for the development of post-radiation macular edema. Material and methods. The study included 63 patients (63 eyes) who underwent Ru/Rh106 brachytherapy for choroidal melanoma (CM). The mean total focal dose (TFD) at the apex was 123.95±8.1 Gy, and the mean TFD on the sclera was 760.88±503.81 Gy. TNM staging: T1 — 18 patients, T2 — 18, T3 — 27. The mean tumor prominence was 4.37±2.21 mm, and the mean base width was 11.07±2.93 mm. We analyzed nine risk factors for the development of post-radiation macular edema. The observation period ranged from 12 to 48 months. Results and discussion. Post-radiation macular edema was found in 41% of cases. Medical therapy for post-radiation macular edema in 11 patients began with periocular administration of extended-release glucocorticoids (GCs). In 4 cases, this therapy led to complete regression of post-radiation macular edema. Seven patients required additional intravitreal injections of extended-release GC implants, resulting in complete regression of macular edema in 6 patients. In 12 patients, secondary neovascularization in the macular and paramacular areas was detected based on optical coherence tomography angiography data. Intravitreal injections of angiogenesis inhibitors were performed for these patients. Treatment led to complete regression of post-radiation macular edema in 7 patients and partial regression in 5. Conclusion. Significant risk factors for developing this complication include post-equatorial CM location and pronounced early postoperative radiation reactions. Medical treatment of post-radiation macular edema is possible using extended-release GCs and intravitreal injections of angiogenesis inhibitors.