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Updated: Aug 29, 2026
Establishment and Propagation of Human Retinoblastoma Tumors in Immune Deficient Mice
Published on: August 4, 2011
External beam radiation "salvage" therapy in transgenic murine retinoblastoma
Lucia Sobrin1, Brandy C Hayden, Timothy G Murray
1Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami, Miami, FL 33101, USA.
Objective:
To determine the efficacy of low-dose "salvage" external beam radiation therapy (EBRT) following failed subconjunctival carboplatin chemotherapy in a murine model of heritable retinoblastoma.
Methods:
Eighty-four eyes from 8-week-old, simian virus 40, T-antigen-positive mice were treated with 6 serial subconjunctival carboplatin injections (100 microg/25 microL). At 12 weeks of age, 64 eyes received EBRT for a total dose of 480 (4.8 Gy), 1200 (12.0 Gy), 1560 (15.6 Gy), or 3000 (30.0 Gy) rad. Twenty eyes received no additional therapy following subconjunctival carboplatin injections. Ten eyes received a total dose EBRT of only 3000 rad. Eight eyes received subconjuctival injections of only an isotonic sodium chloride solution. Ten eyes served as untreated controls.
Main Outcome Measures:
Eyes were enucleated at 20 weeks to assess the presence of tumor on histopathological examination.
Results:
Salvage therapy using low-dose EBRT was able to reestablish tumor control in a dose-dependent manner. Increasing the EBRT dose to 3000 rad resulted in 100% tumor control. The dose-dependent curves were significantly different between the treatment groups-EBRT alone vs salvage EBRT after receiving subconjunctival carboplatin injections (P<.001).
Conclusion:
Low-dose hyperfractionated salvage EBRT following failed primary subconjunctival carboplatin chemotherapy is efficacious in the treatment of retinoblastoma in this animal model. Clinical Relevance Salvage EBRT using a reduced total radiation dose could be associated with a radiation-related treatment enhancement in pediatric retinoblastoma.
