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/...