Efficacy and safety of proton radiotherapy in treating choroidal melanoma: a systematic review and meta-analysis

Background: Proton beam therapy (PBT) has been gradually introduced for treating choroidal melanoma. This study systematically reviewed clinical reports to evaluate the efficacy and safety of PBT in choroidal melanoma patients.

Methods: This systematic review included all the primary studies involving PBT for choroidal melanoma patients through April 2024. Four publicly accessible databases were searched, and the statistical data were analyzed using STATA 15.0. The outcomes of interest included overall survival (OS), metastasis-free survival, local control rate, and adverse reactions.

Results: A total of six case series involving 1059 patients with choroidal melanoma were included. The random effect model meta-analysis showed that the 2-, 3-, 5-, and 10-year OS rates of patients with choroidal melanoma treated with PBT were 97%, 92%, 73%, and 39%, respectively. The metastasis-free survival rates at 2, 3, and 5 years were 92%, 89%, and 76%, respectively, and the local control rates at 1, 3, 5, and 10 years were 98%, 92%, 94%, and 88%, respectively. Four studies reported adverse reactions. The most common adverse reactions after PBT were glaucoma, optic neuropathy, and cataracts, with incidence rates ranging from 17.9 to 27%, 12.8-64%, and 29.6-39.8%, respectively.

Conclusions: This meta-analysis identified PBT as a vital local treatment strategy against choroidal melanoma. Both OS and local control rates showed excellent results. However, more prospective trials can help compare the efficacy of PBT with typical therapy.