VSV therapy in subcutaneous C1498 tumors. (A) Representative SPECT/CT images of tumors (circled) in mice (n = 3 per group) that received VSV-mIFNβ-NIS, with and without anti-PD-L1 Ab (given 6 hours later). Eight serial sections through similar locations of the same mouse reveal NIS expression in VSV infectious foci distributed throughout the tumor. (B) Dose-dependent study on antitumor activity of VSV-mIFNβ-NIS against subcutaneous C1498 tumors. Mice were harvested 30 days post-tumor cell implantation and tumors were weighed. Mean ± SEM (n = 5 mice) from each group is plotted. *P ≤ .05. Unpaired Student t test was used. SEM, standard error of the mean.