Figure 2.

PET/CT images before and after treatment. A, PET/CT at diagnosis (PET/CT0); B, PET/CT after 2 cycles of chemotherapy (PET/CT2); C, PET/CT after 4 cycles of chemotherapy (PET/CT4); D, PET/CT at the end of treatment (F-PET/CT). If the PET/CT4 or F-PET/CT findings are compared with PET/CT0 alone, disease progression might be misinterpreted as partial remission. This patient received involved field radiotherapy after 6 cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), but the disease progressed and he died after 27 months.