Tumour control, eye retention and visual acuity after radiotherapy for choroidal melanoma.

OBJECTIVE: Radiotherapy modalities such as iodine-125 (I125) and ruthenium-106 (Ru106) brachytherapy and proton beam radiotherapy (PBR) are well established for the treatment of choroidal melanoma. This study aimed to evaluate the rates of local tumour control, globe retention and visual acuity (VA) outcomes in patients with choroidal melanoma treated with I125 or Ru106 brachytherapy or PBR. METHODS AND ANALYSIS: A review was conducted of all cases of choroidal melanoma treated with Ru106 or I125 brachytherapy or PBR over a 10-year period. Patient demographics, comorbidities, tumour characteristics, treatment parameters and VA outcomes were analysed. A predictive nomogram was developed to estimate final VA based on baseline clinical, tumour and radiation parameters. RESULTS: A total of 310 eyes from 310 patients were included, comprising 175 patients (56.5%) treated with Ru106, 72 (23.2%) treated with I125 brachytherapy and 63 (20.3%) treated with PBR. Local tumour control was achieved in 95.8% of cases. The recurrence rates were 4.0%, 4.2% and 4.8% for Ru106, I125 and PBR, respectively. Retention rates were 96.0% for Ru106, 94.4% for I125 and 95.2% for PBR. LogMAR VA of 1.0 or better was maintained in 50.9% of Ru106patients, 27.8% of I125patients and 39.7% of those treated with PBR. Baseline LogMAR VA, tumour volume, radiation dose to the fovea, radiotherapy modality and follow-up duration were significant predictors of final VA and were incorporated into the nomogram. CONCLUSIONS: Each radiotherapy modality demonstrated high rates of local tumour control and globe retention. The predictive nomogram may serve as a practical tool to support individualised visual prognostication and patient counselling in the management of choroidal melanoma.