Local Radiation Complications Following Proton Therapy for Uveal Melanoma

Purpose : to study the frequency and clinical symptoms of local radiation complications that occur after proton therapy in patients with uveal melanoma using pencil beam scanning technology. Patients and methods : The retrospective analysis included 35 patients with uveal melanoma who received proton therapy using pencil beam scanning technology in hypofractionation mode at a dose of 49 Gy in 7 fractions. The initial tumor prominence was 9.2 mm (Me 9.7; IQR 2.75), the base diameter was 16.1 mm (Me 16.5; IQR 11.25), and the follow-up period was 3 to 54 months (Me 13.0; IQR 9.5 months). Results . In the study group, sustained local tumor control was achieved in all patients, and complete tumor regression was observed in 3 patients in 22–26 months after the start of treatment. With a median follow-up of 13.0 months, a wide range of various radiation-related complications was observed, with the most common being ophthalmic hypertension (54.3 %), cataract (51.4 %), and neovascular glaucoma (34.3 %). In addition, dermatitis (34.4 %), dry eye syndrome (17.1 %), post-radiation retinopathy (14.3 %), hemophthalmus (8.6 %), and scleromaly (2.9 %) were recorded at various times. Secondary enucleation was performed in 6 (17.1 %) of the treated patients due to the development of secondary neovascular glaucoma or corneal ulcer with a risk of perforation. Conclusion . Proton therapy with a scanning pencil beam in hypofractionation mode in the treatment of UM is characterized by the same effectiveness of the local effect on the tumor and the range and frequency of post-radiation complications as the literature data. Not only the improvement of technology, the development of preventive measures, but also the definition of clear criteria for indications and limitations for the use of this treatment method are required to reduce the risk of developing post-radiation damage.