Monitor response to therapy in lymphoma: The patient shown below was a 29 year old male with a history of recurrent lymphoma despite chemotherapy and stem cell transplant. The patients initial PET scan (left) demonstrated extensive nodal disease throughtout the neck, chest, abdomen, and pelvis. The patient was treated with a repeat stem cell transplant. A post-treatment FDG PET exam demonstrated interval resolution of previously identified sites of disease consistent with a response to therapy. Note renal collecting system activity on both studies.