Neuroblastoma is a disease that originates from the unregulated proliferation of neuroblasts—immature nerve cells—in the adrenal glands, neck, chest and spinal cord of children. It is the third most common pediatric tumor and the most common tumor under the age of one. The innovative virotherapy Celyvir fights cancer using an oncolytic virus. To avoid detection by the immune system, the virus is delivered to the tumor encapsulated in mesenchymal cells. We develop mathematical models that capture the most relevant features of the disease and treatment. With them, we perform analytical analyses and simulate many cases in a computer to identify the conditions in which Celyvir will be more successful.