Radiosynthesis of [(18)F]fluoromethyldeoxyspergualin for molecular imaging of heat shock proteins.

To probe the in vivo role of stress response factors in normal physiology and in solid tumors we have designed a stable (18)F-labeled molecular imaging agent based on a ligand for heat shock protein 70 (HSP70). We describe the synthesis of [(18)F] fluorodeoxymethylspergualin ([(18)F]MeDSG) as a new radiopharmaceutical probe using a prosthetic group, [(18)F]SFB, for efficient and rapid radiolabeling. Ongoing molecular imaging studies are under way to detect HSP70 expression in tumors by positron emission tomography.