Orbital and Metastatic Retinoblastoma: Conquests and Challenges

Abstract

Orbital and metastatic retinoblastoma (RB) are advanced stages of extra-ocular retinoblastoma which present at a late stage to the clinic and carry a worse prognosis as compared to intraocular RB. The two most commonly used staging systems to denote these entities are the International Retinoblastoma Staging System and the American Joint Commission on Cancers’ TNMH staging. The imaging modality of choice is a Contrast Enhanced Magnetic Resonance Imaging of the orbit and brain to confirm the diagnosis and detect extraocular spread including optic nerve infiltration. There is scarcity of literature on a uniform and standard treatment protocol used to treat these advanced stages of disease. With the incorporation of multimodal therapy consisting of neo-adjuvant chemotherapy, enucleation, external beam orbital radiotherapy, and adjuvant chemotherapy, the outlook of orbital RB has improved dramatically, although the prognosis of metastatic disease in developing countries is still dismal. A proportion of distant metastatic disease can be cured with intensive multimodal chemotherapy and autologous stem cell rescue; however, patients with CNS disease require development of novel management strategies to improve their survival. Apart from these concerns, monitoring for and management of long-term adverse effects of treatment like sensorineural hearing loss, development of subsequent malignant neoplasms (SMN), diminished orbital growth following radiotherapy, and impaired neurocognitive functioning should also be given priority. Creating awareness among primary healthcare providers and the general population through community education programs will help in early diagnosis, when the disease is still intra-ocular, and will prevent late presentations to the clinic.