2-[18F]fludarabine, a novel positron emission tomography (PET) tracer for imaging lymphoma: a micro-PET study in murine models.

PURPOSE

Fludarabine has proven to be of considerable efficacy in the treatment of low-grade lymphomas. We have developed the labeling of this drug with fluorine-18 and evaluated 2-[(18)F]fludarabine as a novel positron emission tomography (PET) probe for in vivo imaging.

PROCEDURES

Preclinical studies were conducted with 2-[(18)F]fludarabine, in parallel with 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG), in Swiss CD-1 and CB17 severely combined immunodeficient (SCID) mice, both as tumor-free control groups, and SCID mice bearing RL lymphomas.

RESULTS

In Swiss mice, micro-PET studies with 2-[(18)F]fludarabine showed a distribution restricted to the organs of excretion and the spleen, the latter being less evident in SCID animals. In lymphoma-bearing SCID mice, 2-[(18)F]fludarabine demonstrated a rapid tumor uptake over the first 20 min which subsequently plateaued and provided an improved contrast than that of [(18)F]FDG.

CONCLUSION

This radiotracer merits further evaluation to establish its clinical usefulness to image low-grade lymphoma in humans in future clinical investigations.