Objective: To describe the clinical outcomes of patients treated by proton beam irradiation for choroidal metastatic tumors. Design: Noncomparative case series. Participants: A retrospective chart review was performed on a series of 63 patients (76 eyes) with choroidal metastases treated with proton beam therapy between December 1989 and September 2000. Methods:Patients were treated with 2 fractions of 14 cobalt gray equivalents (CGEs) (CGE=proton Gy x relative biological effectiveness 1.1), each using a nonoperative “ light- field” technique. Ophthalmologic follow- up was available for 46 patients (55 eyes), with a mean follow- up time of 10 months. The medical record or the Social Security Death Index was used to obtain survival status, which was available in 94% of cases. Main Outcome Measures: Tumor regression, recurrence, treatment associated complications, and visual acuity were evaluated by ophthalmologic examination and ultrasonography. Eye retention and length of survival also were assessed. Results: At the time of ocular diagnosis,49 patients reported a history of a primary cancer. Median survival time after ocular diagnosis was 16 months through May 2003. Most choroidal metastases were dome shaped (62% ) and located at the posterior pole (95% ). Mean tumor height was approximately 3.5 mm, and serous retinal detachment was seen in 63% of cases. Eighty- four percent of treated tumors regressed completely with in 5 months of treatment, and none of these recurred. Retinal detachment resolved in 82% of patients within 3.8 months after treatment, and visual acuity was preserved or improved in 47% of the patients. Complications occurred in 56% of cases and included madarosis, keratitis, dry eye syndrome, cataract, neovascular glaucoma, chorioretinal atrophy, radiation papillopathy, and radiation maculopathy. None of the treated eyes required enucleation. Conclusions: Proton beam irradiation is a useful therapeutic approach for choroidal metastases; it allows retention of the globe, achieves a high probability of local tumor control, and helps to avoid pain and visual loss. Although complications occur in most cases, many of these are minor and are not associated with a change in function. This modality is accurate and efficient, because it only entails 2 treatment fractions and does not require surgery for tumor localization. Objective: To describe the clinical outcomes of patients treated by proton beam irradiation for choroidal metastatic tumors. Design: Noncomparative case series. Participants: A retrospective chart review was performed on a series of 63 patients (76 eyes) with choroidal metastases treated with proton beam therapy between December 1989 and September 2000. Methods: Patients were treated with 2 fractions of 14 cobalt gray equivalents (CGEs) (CGE = proton Gy x relative biological effectiveness 1.1), each using a nonoperative “light- field” technique. Ophthalmologic follow- The medical record or the Social Security Death Index was used to obtain survival status, which was available in 94% of cases. Main Outcome Measures (55 eyes), with a mean follow-up time of 10 months. : Tumor regression, recurrence, treatment associated complications, and visual acuity were evaluated by ophthalmologic examination and ultrasonography. Eye retention and length of survival also at assessed. Results: At the time of ocular diagnosis, 49 patients reported a history of a primary cancer. Median survival time after ocular diagnosis was 16 months through May 2003. Most choroidal metastases were dome shaped (62%) and located at the Eighty-four percent of treated tumors regressed completely with in 5 months of treatment, and none of these recurred. Retinal pole (95%). Mean tumor height was approximately 3.5 mm, and serous retinal detachment was seen in 63% of cases. detachment resolved in 82% of patients within 3.8 months after treatment, and visual acuity was preserved or improved in 47% of the patients. Complications occurred in 56% of cases and included madarosis, keratitis, dry eye syndrome, cataract, neovascular glaucoma, chorioretinal atrophy, radiation papillopathy, and radiation maculopathy. None of the treated eyes required enucleation. Conclusions: Proton beam irradiation is a useful therapeutic approach for choroidal metastases; it allows retention of the globe, achieves a high probability of local tumor control, and helps to avoid pain and visual loss. Though complications occur in most cases, many of these are minor and are not associated with a change in function. This modality is accurate and efficient, because it only entails 2 treatment fractions and does not require surgery for tumor localization.