¹⁸F-FDG PET/CT for Monitoring Response to Therapy for Choroidal Metastasis

A 38-y-old woman with metastatic breast carcinoma reported seeing "halos and flashes" in her left eye. Funduscopic examination revealed an elevated mass in the choroid of the left globe consistent with metastasis. Subsequent ¹⁸F-FDG PET/CT revealed focal uptake in the nasal aspect of the left choroid of the eye corresponding to the mass seen on the funduscopic examination. Through correlation with the PET/CT study, the lesion was retrospectively identified on MRI. The fact that ¹⁸F-FDG PET/CT after radiotherapy showed a complete response supports the use of this imaging modality for diagnosis and monitoring of response. A history of breast cancer and visual symptoms should trigger the nuclear medicine physician to take extra care in reading the initial slices of the PET/CT scan through the orbits in order to make this challenging imaging diagnosis.