(106)Ru plaque brachytherapy for uveal melanoma: factors associated with local tumor recurrence

Plaque brachytherapy is a common form of treatment for uveal melanoma, and the Collaborative Ocular Melanoma Study (COMS) used (125)I. Recently, (106)Ru has been reintroduced for plaque brachytherapy in the United States. We reviewed our experience treating uveal melanoma with (106)Ru plaque brachytherapy using COMS planning techniques, hypothesizing that we would observe similar outcomes to those in the COMS.

Medical records of patients undergoing (106)Ru plaque brachytherapy were reviewed retrospectively. Patient, tumor, and treatment characteristics were recorded. Outcomes including visual acuity, local tumor recurrence, salvage treatment, metastasis, and survival were recorded. Cox regression analyses were used to determine factors associated with local tumor recurrence and enucleation.

Twenty-eight patients were studied. Median age was 60 years, and 50% were men. Median tumor base diameter and height were 9.4 and 2.6 mm, respectively. Ophthalmic complications were rare. Local tumor recurrence and enucleation occurred in 13 and 4 patients, respectively. Local tumor recurrence was associated with low visual acuity in the tumor-bearing eye, posterior tumors, small plaque size, and difference in plaque-tumor diameter of <6 mm. Enucleation was associated with low visual acuity and posteriorly located tumor. Estimated 5-year rate of death and metastasis was 18.5% and 11.4%, respectively.

Among patients treated with (106)Ru plaque brachytherapy using COMS planning techniques, we found a greater than expected rate of local tumor recurrence. Planning (106)Ru plaque brachytherapy should be done carefully at centers that have previously used COMS protocols and (125)I.