To compare tumor control, vision, and complications between patients with a choroidal melanoma <10 mm in largest basal diameter (LBD) irradiated with 10-mm or 15-mm ruthenium plaques.
Retrospective comparative case series PARTICIPANTS: One hundred sixty-four consecutive patients with a choroidal melanoma <10 mm in LBD, 76 and 88 treated with the 10-mm and 15-mm plaque, respectively, in 1998-2014 in a national ocular oncology service.
Diagnosis was based on growth or high-risk characteristics. The apical dose was 100-120 Gy aiming to deliver ≥250 Gy to the sclera. Plaque positioning was retrospectively modeled. An increase ≥0.3 mm in thickness and ≥0.5 mm in LBD indicated local recurrence. Outcomes were compared with cumulative incidence analysis and Cox regression. Median follow-up time for patients still alive was 8.4 years.
Recurrence rate, low vision, blindness, radiation maculopathy and optic neuropathy.
Melanomas treated with the 10-mm plaque were smaller (median thickness, 1.9 vs 2.6 mm; LBD 7.1 vs 8.6 mm), and located closer to foveola (median, 2.0 vs 2.8 mm) than those treated with the 15-mm plaque (P<0.001). The two plaques provided a safety margin in 43% vs 40% eyes, no safety margin, to guard foveola, in 17% vs 33%, and did not entirely cover tumor, mainly close to the disk, in 32% vs 18% of eyes, respectively (P=0.052). The incidence of a local recurrence was comparable (13% vs 15% at 10 years; P=0.31) and associated with plaque positioning (hazard ratio [HR] 2.81 for no safety margin, P=0.041). At 5 years, the incidence of low vision was 14% vs 24%, and that of blindness 3% vs 6%. Distance to foveola was associated with loss of both levels of vision (HR, 0.65 vs 0.68 per mm, P=<0.001 vs P=0.004). The incidence of radiation maculopathy was comparable (19% vs 18% at 5 years) whereas that of optic neuropathy tended to be higher with the 15-mm plaque (2% vs 9%; P=0.054).
The 10-mm ruthenium plaque contributes to better visual preservation, particularly with tumors close to fovea, without increase in local recurrence rate and, therefore, may be preferable to the 15-mm plaque.

Copyright © 2020. Published by Elsevier Inc.