Gamma Knife for the Treatment of Choroidal Breast Cancer Metastasis Causing Retinal Detachment: A Case Report

Jee Yan Ong¹Ereena Alfian²Ramesh Kumar²Fuad Ismail³Niki Wai Wye Ho¹Mae-Lynn Catherine Bastion¹Othmaliza Othman^1*

• ¹Department of Ophthalmology, Hospital Canselor Tuanku Muhriz, Universiti Kebangsaan Malaysia, Malaysia, Kuala Lumpur, Malaysia
• ²Neurosurgical Unit, Department of Surgery, Hospital Canselor Tuanku Muhriz, Universiti Kebangsaan Malaysia, Malaysia, Kuala Lumpur, Malaysia
• ³Department of Radiology and Oncology, Hospital Canselor Tuanku Muhriz, Universiti Kebangsaan Malaysia, Malaysia, Kuala Lumpur, Malaysia

Introduction: Choroidal metastasis generally has poor prognosis and are most commonly originated from breast carcinomas.1,2 While systemic chemotherapy offers therapeutic benefits, local therapies are often necessary for symptom management and tumor control. Gamma Knife Radiosurgery (GKR), originally developed for intracranial lesions, has emerged as a promising treatment for choroidal metastasis, offering high precision and minimized toxicity with fewer ocular side effects compared to conventional radiotherapy. This case report explores the use of GKR in a patient with choroidal and brain metastases from breast carcinoma. Case Presentation: A 44-year-old woman with a history of treated left breast carcinoma presented with 3 months gradual vision loss in her left eye. Her visual acuity at presentation was Counting Fingers (CF). Imaging revealed a choroidal metastasis along with multiple brain metastases. The patient underwent GKR for both choroidal and intracranial metastases, receiving doses ranging from 16-18 Gy at 50-90% isodose. Following treatment, significant tumor regression was observed, with marked reduction in retinal detachment and vision improvement to 6/18. At post-GKR 6 months, both the choroidal mass and retinal detachment had fully resolved, but her visual acuity remained limited due to fovea atrophy. Conclusion: This case demonstrates GKR's potential as a non-invasive and effective modality for simultaneous treatment of choroidal and intracranial metastases. In palliative settings, especially for patients with limited life expectancy, GKR can provide symptomatic relief and improved life quality with minimal invasiveness, which is particularly valuable for younger patients facing advanced metastatic cancer. The importance of a multidisciplinary approach in managing complex metastatic disease is also highlighted. Future studies are warranted to fully define the role of GKR in choroidal metastasis and its long-term sequelae.