Is retinoblastoma fatal?

Treatable. Retinoblastoma is one of the most treatable malignancies of childhood. The cure rate is 95 to 98% with currently available treatment.
Usually not! Retinoblastoma is a cancer of the back of the eye. It shows up during childhood, and can affect one or both eyes. About 1/4 of cases are due to an inherited gene (rb1). It is curable in over 90% of cases. Treatment involves radiation, chemotherapy, and surgery; sometimes it requires removal of the eye. It can recur so long-term surveillance is necessary even when it's cured.
Yes. If is diagnosed to late with brain metastasis.