A cohort of long-surviving patients affected by small and medium uveal melanoma treated with ruthenium-106 plaque brachytherapy

Introduction: This study reports the long-term outcomes in patients affected by uveal melanoma (UM) treated with ruthenium-106 (106Ru) plaque brachytherapy (BT). Material and methods: From May 2005 to January 2024, 127 patients (median age: 69 years, range: 32-90 years) affected by small and medium UM were treated with 106Ru plaque BT at the University Hospital of Pisa. All the patients were treated with 106Ru plaque BT with a prescription dose of 110 Gy to the tumor apex. Results: Inclusion criteria comprised Eastern Cooperative Oncology Group performance status <= 2, life expectancy > 6 months, and tumor thickness <= 6 mm and/or diameter <= 16 mm. The 5-year rate of local control, progression-free survival, metastasis-free survival, and overall survival were 95.2%, 85.4%, 93.0%, and 95.9%, respectively. Local progression was recorded in nine patients (7.1%): two of them (1.6%) had also distant metastasis. Seven patients were retreated with photon beam and one patient with proton beam stereo- tactic radiosurgery; one patient was retreated with 125I plaque BT. Only one patient underwent enucleation for large local progression after about 10 years. Thirty-four patients (26.8%) had one or more acute and late toxicities. No grade 4 acute or late toxicity was reported. Conclusions: This study suggests that 106Ru plaque BT is a successful and well-tolerated radiotherapy technique in the management of UM.