title: [[(18)F]N-(4'-fluorobenzyl)-4-(3-bromophenyl) acetamide for imaging the sigma receptor status of tumors: comparison with [(18)F]FDG, and [(125)I]IUDR.
abstract: A series of biodistribution studies were conducted with the radiotracer, [(18)F]N-(4'-fluorobenzyl)-4-(3-bromophenyl)acetamide, [(18)F]1 in nude mice bearing tumor xenografts of the mouse mammary adenocarcinoma, line 66. This radiotracer has a high affinity for both sigma(1) and sigma(2) receptors. In vivo studies were also conducted in order to assess the effect of blocking sigma(1) receptors on tumor uptake and the tumor:background ratio of this radiotracer. The results of these studies revealed that blocking the sigma(1) receptor so that only the sigma(2) receptors are labeled in vivo, results in a higher tumor:background ratio with only a small reduction in the tumor uptake of the radiotracer relative to the no-carrier-added (i.e., nonselective) conditions. Comparative in vivo studies were also conducted with the anatomic and metabolic imaging agent, [(18)F]FDG, and a radiolabeled DNA precursor, [(125)I]IUdR. Both of these radiolabeled compounds represent classes of agents that have been proposed for imaging the proliferative status of solid tumors. The results of these studies indicated that a sigma(2)-selective imaging agent may be, 1) a better anatomic imaging agent for breast cancer than [(18)F]FDG, and 2) a better functional imaging agent than the radiolabeled DNA precursors, [(123/124)I]IUdR and [(11)C]thymidine, for measuring the proliferative status of breast tumors with PET and SPECT. However, additional studies will be needed to compare sigma(2)-selective imaging agents with [(18)F]FLT in order to determine which is the more appropriate imaging agent for measuring the proliferative status of breast tumors with PET.
authors.affiliation: Department of Radiology-PET Center, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
authors.forename: R H
authors.initials: RH
authors.lastname: Mach
authors.forename: Y
authors.initials: Y
authors.lastname: Huang
authors.forename: N
authors.initials: N
authors.lastname: Buchheimer
authors.forename: R
authors.initials: R
authors.lastname: Kuhner
authors.forename: L
authors.initials: L
authors.lastname: Wu
authors.forename: T E
authors.initials: TE
authors.lastname: Morton
authors.forename: L
authors.initials: L
authors.lastname: Wang
authors.forename: R L
authors.initials: RL
authors.lastname: Ehrenkaufer
authors.forename: C A
authors.initials: CA
authors.lastname: Wallen
authors.forename: K T
authors.initials: KT
authors.lastname: Wheeler
mesh_terms: D000081:Acetamides / Q000138:chemical synthesis*; D000230:Adenocarcinoma / Q000000981:diagnostic imaging; D000818:Animals; D005260:Female; D019788:Fluorodeoxyglucose F18; D007065:Idoxuridine; D008325:Mammary Neoplasms, Experimental / Q000000981:diagnostic imaging; D051379:Mice; D008819:Mice, Nude; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D017480:Receptors, sigma / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D000081:Acetamides; C434767:N-(4'-fluorobenzyl)-4-(3-bromophenyl)acetamide; D019275:Radiopharmaceuticals; D017480:Receptors, sigma; D019788:Fluorodeoxyglucose F18; D007065:Idoxuridine