Because of the poor prognosis of trilateral retinoblastoma, screening neuroimaging is a common practice. While it is not clear whether early diagnosis can impact survival, the frequency of screening with magnetic resonance imaging for those suspected of having hereditary disease or those with unilateral disease and a positive family history has been recommended as often as every 6 months for up to 5 years. Given the short interval between the diagnosis of retinoblastoma and the occurrence of trilateral retinoblastoma, routine screening might detect the majority of cases within 2 years. However, it is not clear that screening by neuroimaging improves survival. Computed tomography scans should be avoided for routine screening in these children because of the perceived risk of exposure to ionizing radiation.
Extracranial metastatic retinoblastoma
Hematogenous metastases may develop in the bones, bone marrow, and less frequently, in the liver. Although long-term survivors have been reported with conventional chemotherapy, these reports should be considered anecdotal; metastatic retinoblastoma is not curable with conventional chemotherapy. In recent years, however, studies of small series of patients have shown that metastatic retinoblastoma can be cured using high-dose marrow-ablative chemotherapy and autologous hematopoietic stem cell rescue.[5,6,7,8,9,10]; [Level of evidence: 3iiA]
There is no clearly proven effective or standard therapy for the treatment of extraocular retinoblastoma, although orbital irradiation and chemotherapy have been used. In the past, palliative therapy with radiation therapy (including craniospinal irradiation when there is meningeal involvement) and/or intrathecal chemotherapy with methotrexate, cytarabine, and hydrocortisone, plus supportive care has been used. A retrospective study showed that extraocular disease, manifested by gadolinium enhancement on magnetic resonance imaging of the proximal optic nerve, might respond to treatment with neoadjuvant chemotherapy prior to enucleation.[Level of evidence: 3iiDi]
Treatment Options Under Clinical Evaluation
Two reports suggest that there may be a role for intensive multimodality therapy with autologous stem cell rescue for patients with metastatic retinoblastoma.[2,11][Level of evidence: 3iiA] A few responses were noted in both CNS (including trilateral) and systemic metastases. However, these strategies remain under clinical investigation.
The following is an example of national and/or institutional clinical trial that is currently being conducted. Information about ongoing clinical trials is available from the NCI Web site.
- COG-ARET0321 (Combination Chemotherapy, Autologous Stem Cell Transplant [SCT], and/or Radiation Therapy in Treating Young Patients With Extraocular Retinoblastoma): Patients with metastatic or recurrent retinoblastoma that is beyond the globe are eligible for treatment with combined conventional chemotherapy, high-dose chemotherapy, and SCT with conventional radiation.
Current Clinical Trials
Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with extraocular retinoblastoma. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.