This ordinary differential equation model of cancer virotherapy dynamics is described in the publication:
Salma M. Al-Tuwairqi, Najwa O. Al-Johani, Eman A. Simbawa,
"Modeling dynamics of cancer radiovirotherapy",
Journal of Theoretical Biology, Volume 506, 2020, 110405, ISSN 0022-5193,
DOI: 10.1016/j.jtbi.2020.110405.

Comment:
This model is represented by the equations in system (2) of the publication manuscript and describes the cancer-virus interactions for the Phase I virotherapy treatment.
Abstract:
Advances in genetic engineering have paved the way for a new therapy for cancer, which is called virotherapy. This treatment uses genetically engineered viruses which selectively infect, replicate in, and destroy cancer cells without damaging normal cells. Furthermore, current research and clinical trials have indicated that these viruses can be delivered as single agents or in combination with other therapies. In this paper, we propose systems of ordinary differential equations for modeling the dynamics of aggressive tumor growth under radiovirotherapy treatment. We divide the treatment period into two phases; consequently, we present two mathematical models. First, we formulate the virotherapy model as Phase I of the treatment. Then we extend the model to include radiotherapy in combination with virotherapy as Phase II of the treatment. Comprehensive qualitative analyses of both models are conducted. Furthermore, numerical experiments are performed in order to support the analytical results. An analysis of the parameters is also carried out to investigate their effects on the outcome of the treatment. Overall, the analytical results reveal that radiovirotherapy is more effective than, and a good alternative to, virotherapy, as it is capable of eradicating tumors completely.