Visual Outcome and Millimeter Incremental Risk of Metastasis in 1780 Patients With Small Choroidal Melanoma Managed by Plaque Radiotherapy

Abstract

IMPORTANCE Early detection of choroidal melanoma at a small tumor size is emphasized in the literature. However, there is little published information on the specific risks of plaque-irradiated small choroidal melanoma on visual acuity and metastasis. OBJECTIVE To analyze outcomes of plaque radiotherapy for small choroidal melanoma 3 mm in thickness or less. DESIGN, SETTING, AND PARTICIPANTS This retrospective noncomparative series at a tertiary referral center included 1780 consecutive patients who had received plaque radiotherapy treatment for small choroidal melanoma. MAIN OUTCOMES AND MEASURES Visual acuity outcomes and melanoma-associated metastasis, assessed by Kaplan-Meier analyses. RESULTS The mean (SD) patient age at melanoma diagnosis was 58 (14) years. Of 1780 patients, 908 were female (51.0%), and 1752 were white (98.4%). Visual acuity was 20/40 OU or better in 1276 of the patients (71.7%), and the mean (SD) visual acuity was 20/40 (20/50) OU (median, 20/30; range, 20/20 to counting fingers). The mean (SD) tumor basal dimension was 8.8 (2.9) mm (median, 8.0 mm; range, 2.0-20.0 mm) and mean (SD) tumor thickness was 2.6 (0.5) mm (median, 2.7; range, 0.2-3.4 mm). Mean (SD) distance to the foveola was 3.4 (3.9) mm and to the optic disc was 3.7 (3.7) mm. The Kaplan-Meier rate of visual acuity loss (Ն3 Snellen lines) was 9.5% (95% CI, 8.2%-11.0%) at 1 year, 39.2% (95% CI, 36.5%-42.0%) at 5 years, and 48.9% (95% CI, 45.6%-52.3%) at 10 years, whereas poor visual acuity (Յ20/200) was 7.1% (95% CI, 5.9%-8.4%) at 1 year, 38.2% (95% CI, 35.5%-41.1%) at 5 years, and 53.5% (95% CI, 50.1%-57.1%) at 10 years. Regarding melanoma-associated metastasis, the rate was 0.2% (95% CI, 0.09%-0.6%) at 1 year, 4.5% (95% CI, 3.4%-5.9%) at 5 years, and 8.8% (95% CI, 6.9%-11.1%) at 10 years. Using 1.0-mm thickness increments, the 10-year risk for metastasis was 25.0% (95% CI, 3.9%-87.2%) at 0-mm to 1.0-mm thickness, 5.9% (95% CI, 2.5%-13.5%) at 1.1-mm to 2.0-mm thickness, 8.1% (95% CI, 5.9%-11.0%) at 2.1-mm to 3.0-mm thickness, and 13.4% (95% CI, 8.7%-20.4%) at thicknesses greater than 3.0 mm. The greater relative risk (RR) for metastasis in thinnest tumors was 1.83 (95% CI, 1.09-3.07), which likely represented more aggressive diffuse (flat) melanoma. By multivariable analysis, clinical features predictive of melanoma-associated metastasis included increasing patient age (RR, 1.32 [95% CI, 1.07-1.63] per decade; P = .01), tumor diameter (RR, 1.15 [95% CI, 1.06-1.24] per mm; P < .001), tumor thickness (RR, 2.22 [95% CI, 1.22-4.05] per mm; P = .01), photopsia symptoms (RR, 2.45 [95% CI, 1.35-4.43]; P = .003), and prior treatment before plaque radiotherapy (RR, 3.31 [95% CI, 1.31-8.33]; P = .01). CONCLUSIONS AND RELEVANCE This retrospective study suggests that small choroidal melanoma treated with plaque radiotherapy has a 10-year risk for visual acuity loss of 48.9% (95% CI, 45.6%-52.3%) and a 10-risk of systemic metastasis of 8.8% (95% CI, 6.9%-11.1%). In this analysis, each millimeter of increasing thickness and diameter contribut...

Long-Term Visual Outcomes for Small Uveal Melanoma Staged T1 Treated by Proton Beam Radiotherapy

“…A smaller irradiation volume should reduce the radiation toxicity. Recently, Shields et al [4] described visual outcome for 1780 small choroidal melanoma treated by plaque radiotherapy. With this different conservative radiotherapy, the rates of visual acuity inferior to 20/200 were 38.2% (CI95%: 35.5–41.1) at 5 years [4], which is relatively similar to our results.…”

“…Regarding vital prognosis, the overall survival rate was relatively good with 91.7% (95%CI, 88.6–94.9%) at 10 years but T1UM can be a potentially life-threatening disease with 2.8% of metastases at 5 years. Shields et al [4] described prognosis for small choroidal melanoma treated by plaque radiotherapy. They had a risk of metastases of 4.5% (95%CI: 3.4–5.9%) at 5 years, similar to ours.…”

“…Visual outcome and prognosis of small choroidal melanoma after treatment with I 125 plaque radiotherapy were recently described by Shields et al [4]. They reported that small choroidal melanoma can potentially be dangerous, with a 10-year risk for metastasis at 8.8%.…”

Impact of uveal melanoma thickness on post‐plaque radiotherapy outcomes in the prophylactic anti‐vascular endothelial growth factor era in 1131 patients

“…Radiation complications, however, can occur even in those with small melanoma. A recent analysis of 1780 eyes with irradiated small choroidal melanoma demonstrated 10‐year risk of poor visual acuity (≤20/200) in 54%, despite globe salvage in 92% and tumour‐related metastasis of 9% 6 …”

“…Radiation complications directly impact visual acuity 6‐9 . In one analysis of 1106 patients with plaque‐irradiated posterior uveal melanoma of all sizes, and with initial visual acuity of 20/20 to 20/100, long‐term visual acuity at 10 years was reduced to 20/200 or less in 68% 7 .…”