Radiovirotherapy of myeloma tumors in syngeneic, immunocompetent mice. C57BL6/KaLwRij mice with established subcutaneous myeloma tumors were treated with VSV(Δ51)-NIS or VSV(Δ51)-GFP (2 doses of 2.5 × 10⁸ TCID₅₀/dose) without or with ¹³¹I (1 mCi/mouse intraperitoneally 24 hours after virus administration) and tumor volumes are plotted against days after treatment. Arrows indicate virus injections; arrowhead, ¹³¹I injection; points, mean; bars, SE.