A single dose of VSV-IFNβ-NIS monotherapy has clinical activity in patients with TCL. Photographs (A) and PET/CT scans (B) showing resolution of FDG-avid lesions of patient 4A.3 with TCL with cutaneous relapse of nodal PTCL who achieved a CR after receiving 1 dose of VSV-IFNβ-NIS at DL4. (C) FDG PET images of patient 4A.4 with nodal PTCL showing remarkable improvement in FDG-avid cervical, mediastinal, axillary, and abdominal lymph node disease (arrows) with decreased splenic size and FDG uptake (arrowheads) at 1 month. (D) Coronal fused FDG PET/CT images demonstrate improvement in splenic disease (arrowheads), with continued response in the spleen at the 6-month evaluation.