Therapeutic intensification with high-dose, marrow-ablative chemotherapy and autologous hematopoietic progenitor cell rescue has been explored, but its role is not yet clear.[Level of evidence: 3iiA]
Standard treatment options for trilateral retinoblastoma include the following:
- Systemic chemotherapy followed by surgery and myeloablative chemotherapy with stem cell rescue.
- Systemic chemotherapy followed by surgery and radiation therapy.
Trilateral retinoblastoma is usually associated with a pineal lesion or, less commonly, as a suprasellar lesion.[5,6,7] In patients with the heritable form of retinoblastoma, CNS disease is less likely the result of metastatic or regional spread than of a primary intracranial focus, such as a pineal tumor. The prognosis for patients with trilateral retinoblastoma is very poor; most patients die of disseminated neuraxis disease in less than 9 months.[8,9] Trilateral retinoblastoma has been the principal cause of death from retinoblastoma in the United States during the first decade of life.
While pineoblastomas occurring in older patients are sensitive to radiation therapy, current strategies are directed towards avoiding irradiation by using intensive chemotherapy followed by consolidation with myeloablative chemotherapy and autologous hematopoietic progenitor cell rescue, an approach similar to those being used in the treatment of brain tumors in infants.
Because of the poor prognosis of trilateral retinoblastoma, screening with neuroimaging is a common practice in the follow-up of children with the heritable form of the disease. Routine baseline brain magnetic resonance imaging (MRI) is recommended at diagnosis because it may detect trilateral retinoblastoma at a subclinical stage. In a small series of patients, the 5-year overall survival was 67% for those detected at baseline, compared with 11% for the group with a delayed diagnosis. The value of screening with MRI for those suspected of having heritable disease or those with unilateral disease and a positive family history is not determined. MRI screening may be needed as often as every 6 months until the child is age 5 years. Given the short interval between the diagnosis of retinoblastoma and the occurrence of trilateral retinoblastoma, routine screening might detect most cases within 2 years. However, it is not clear whether screening by neuroimaging improves survival.