title: Impact of anesthetics on 3'-[18F]fluoro-3'-deoxythymidine ([18F]FLT) uptake in animal models of cancer and inflammation.
abstract: The aim of this study was to evaluate the impact of different anesthetics on 3'-[18F]fluoro-3'-deoxythymidine ([18F]FLT) uptake in carcinomas and arthritic ankles. To determine the amount of [18F]FLT uptake in subcutaneous CT26 colon carcinomas or arthritic ankles, spontaneously room air/medical air-breathing mice were anesthetized with isoflurane, a combination of medetomidine/midazolam, or ketamine/xylazine. Mice were kept conscious or anesthetized during [18F]FLT uptake before the 10-minute static positron emission tomographic (PET) investigations. [18F]FLT uptake in CT26 colon carcinomas and arthritic ankles was calculated by drawing regions of interest. We detected a significantly reduced (4.4 ± 0.9 %ID/cm3) [18F]FLT uptake in the carcinomas of ketamine/xylazine-anesthetized mice compared to the [18F]FLT-uptake in carcinomas of medetomidine/midazolam- (7.0 ± 1.5 %ID/cm3) or isoflurane-anesthetized mice (6.4 ± 1.5 %ID/cm3), whereas no significant differences were observed in arthritic ankles regardless of whether mice were anesthetized or conscious during tracer uptake. The time-activity curves of carcinomas and arthritic ankles yielded diverse [18F]FLT accumulation related to the used anesthetics. [18F]FLT uptake dynamics are different in arthritic ankles and carcinoma, and the magnitude and pharmacokinetics of [18F]FLT uptake are sensitive to anesthetics. Thus, for preclinical in vivo [18F]FLT PET studies in experimental tumor or inflammation models, we recommend the use of isoflurane anesthesia as it yields a stable tracer uptake and is easy to handle.
authors.affiliation: Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, Department of Preclinical Imaging and Radiopharmacy.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Fuchs
authors.forename: Damaris
authors.initials: D
authors.lastname: Kukuk
authors.forename: Moritz
authors.initials: M
authors.lastname: Mahling
authors.forename: Leticia
authors.initials: L
authors.lastname: Quintanilla-Martinez
authors.forename: Gerald
authors.initials: G
authors.lastname: Reischl
authors.forename: Jörg
authors.initials: J
authors.lastname: Reutershan
authors.forename: Florian
authors.initials: F
authors.lastname: Lang
authors.forename: Martin
authors.initials: M
authors.lastname: Röcken
authors.forename: Bernd J
authors.initials: BJ
authors.lastname: Pichler
authors.forename: Manfred
authors.initials: M
authors.lastname: Kneilling
mesh_terms: D000777:Anesthetics / Q000494:pharmacology*; D000818:Animals; D015224:Dideoxynucleosides / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D004195:Disease Models, Animal; D005260:Female; D007150:Immunohistochemistry; D007249:Inflammation / Q000000981:diagnostic imaging* / Q000473:pathology; D019394:Ki-67 Antigen / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D011877:Radionuclide Imaging
chemical_list: D000777:Anesthetics; D015224:Dideoxynucleosides; D019394:Ki-67 Antigen; C002854:alovudine