Uveal Melanoma: Proton Beam Radiation Therapy

Radiotherapy (RT) is the standard of care for the vast majority of malignant melanomas of the uveal tract. Brachytherapy and external beam radiation with heavy charged particles, such as protons, are used to treat most choroidal and ciliary body tumors, and high rates of local control are achieved with both modalities. However, highly localized and uniform dose distributions can be delivered with proton beam radiotherapy, which makes it particularly advantageous for treating large tumors and tumors located close to the optic nerve or macula. Eye conservation and, in many cases, maintenance of useful vision are possible, but vision-threatening complications such as maculopathy and papillopathy can occur. Despite high rates of local control and maintenance of ocular function, primary treatment modality has no effect on survival, with similar rates of metastasis- and melanoma-related mortality observed in patients who undergo enucleation or receive radiotherapy. Currently there are no effective treatments for metastatic uveal melanoma, which develops in the liver in most cases. Further research to discover new therapies and preventive strategies is necessary to improve survival.