Enhanced 18F-FDG bone marrow uptake following G-CSF: How much does it affect tumor SUV?
628 Objectives: Patients receiving chemo or radiation therapy are often also treated with granulocyte colony stimulating factors (G-CSFs). G-CSF can enhance FDG bone marrow uptake. It has been hypothesized (Jacene et al, JNM 2006;47;950-956) that this might reduce arterial FDG available to the tumor, and so reduce tumor standardized uptake values (SUV), confounding interpretation of pre/post therapy FDG PET scans. We tested this hypothesis by segmenting all bone in whole body CT scans, measuring total FDG uptake in bone marrow, and computing its effect on tumor SUV. Methods: Total FDG in bone marrow was measured in 2 groups of PET/CT patients: one (n=12) treated with G-CSF 1 to 3 weeks prior to PET/CT, the other (n=5), a baseline group who underwent PET/CT for staging or restaging and had not received G-CSF. Neither group had bone metastases by CT or PET evaluation. Segmented CT of the full skeleton was used to measure bone marrow uptake in co-registered PET. Kinetic analysis was used
