A comparison of the imaging characteristics and microregional distribution of 4 hypoxia PET tracers Journal Article


Authors: Carlin, S.; Zhang, H.; Reese, M.; Ramos, N. N.; Chen, Q.; Ricketts, S. A.
Article Title: A comparison of the imaging characteristics and microregional distribution of 4 hypoxia PET tracers
Abstract: We compared the imaging characteristics and hypoxia selectivity of 4 hypoxia PET radiotracers ((18)F-fluoromisonidazole [(18)F-FMISO], (18)F-flortanidazole [(18)F-HX4], (18)F-fluoroazomycin arabinoside [(18)F-FAZA], and (64)Cu-diacetyl-bis(N4-methylsemicarbazone) [(64)Cu-ATSM]) in a single murine xenograft tumor model condition using small-animal PET imaging and combined ex vivo autoradiography and fluorescence immunohistochemistry. Nude mice bearing SQ20b xenograft tumors were administered 1 of 4 hypoxia PET tracers and images acquired 80-90 min after injection. Frozen sections from excised tumors were then evaluated for tracer distribution using digital autoradiography and compared with histologic markers of tumor hypoxia (pimonidazole, carbonic anydrase 9 [CA9]) and vascular perfusion (Hoechst 33342). The highest tumor uptake was observed with (64)Cu-ATSM (maximum standardized uptake values [SUV(max)], 1.26 ± 0.13) and the lowest with (18)F-FAZA (SUVmax, 0.41 ± 0.24). (18)F-FMISO and (18)F-HX4 had similar intermediate tumor uptake (SUV(max), 0.76 ± 0.38 and 0.65 ± 0.19, respectively). Digital autoradiographs of hypoxia tracer distribution were compared pixel by pixel with images of immunohistochemistry stains. The fluorinated nitroimidazoles all showed radiotracer uptake increasing with pimonidazole and CA9 staining. (64)Cu-ATSM showed the opposite pattern, with highest radiotracer uptake observed in regions with the lowest pimonidazole and CA9 staining. The fluorinated nitroimidazoles showed similar tumor distributions when compared with immunohistochemistry markers of hypoxia. Variations in tumor standardized uptake value and normal tissue distribution may determine the most appropriate clinical setting for each tracer. (64)Cu-ATSM showed the highest tumor accumulation and little renal clearance. However, the lack of correlation between (64)Cu-ATSM distribution and immunohistochemistry hypoxia markers casts some doubt on the hypoxia selectivity of (64)Cu-ATSM.
Keywords: comparative study; positron emission tomography; methodology; mouse; animal; metabolism; animals; mice; immunofluorescence; cell line, tumor; hypoxia; diagnostic agent; tumor cell line; positron-emission tomography; cell hypoxia; radioactive tracers; tracer; pet; organometallic compound; organometallic compounds; thiosemicarbazone derivative; copper; copper (ii) diacetyl di(n(4) methylthiosemicarbazone); copper (ii) diacetyl-di(n(4)-methylthiosemicarbazone); thiosemicarbazones; nitroimidazole derivative; autoradiography; nitroimidazoles; copper radioisotopes; humans; human; article; animal imaging
Journal Title: Journal of Nuclear Medicine
Volume: 55
Issue: 3
ISSN: 0161-5505
Publisher: Society of Nuclear Medicine  
Date Published: 2014-03-01
Start Page: 515
End Page: 521
Language: English
PROVIDER: scopus
PUBMED: 24491409
DOI: 10.2967/jnumed.113.126615
PMCID: PMC4232233
DOI/URL:
Notes: J. Nucl. Med. -- Export Date: 2 June 2014 -- Source: Scopus
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MSK Authors
  1. Hanwen Zhang
    34 Zhang
  2. Sean Denis Carlin
    83 Carlin
  3. Megan L Reese
    4 Reese
  4. Nicholas Ramos
    8 Ramos
  5. Qing Chen
    19 Chen