title: 99mTc- and 111In-labeled alpha-melanocyte-stimulating hormone peptides as imaging probes for primary and pulmonary metastatic melanoma detection.
abstract: It is highly desired to develop new imaging probes for early detection of melanoma as early diagnosis and prompt surgical removal are a patient's best hope for a cure. The purpose of this study was to determine whether (99m)Tc- and (111)In-labeled alpha-melanocyte-stimulating hormone (alpha-MSH) peptides could be used as imaging probes for primary and metastatic melanoma using dual-modality micro-SPECT/CT detection.
  
  
  METHODS
  [Cys(3,4,10),d-Phe(7),Arg(11)]alpha-MSH(3-13) [(Arg(11))CCMSH] and [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]Re(Arg(11))CCMSH [DOTA-Re(Arg(11))CCMSH] were labeled with (99m)Tc and (111)In. The pharmacokinetics of (99m)Tc-(Arg(11))CCMSH were examined in B16/F1 flank and B16/F10 pulmonary metastatic murine melanoma-bearing C57 mice. The biodistribution of (111)In-DOTA-Re(Arg(11))CCMSH was performed in B16/F10 pulmonary metastatic murine melanoma-bearing C57 mice. SPECT/CT of (99m)Tc-(Arg(11))CCMSH and (111)In-DOTA-Re(Arg(11))CCMSH was determined in B16/F1 flank and B16/F10 pulmonary metastatic murine melanoma-bearing C57 mice.
  
  
  RESULTS
  (99m)Tc-(Arg(11))CCMSH and (111)In-DOTA-Re(Arg(11))CCMSH exhibited high tumor uptakes (14.03 +/- 2.58 percentage injected dose/gram [%ID/g] at 1 h after injection and 17.29 +/- 2.49 %ID/g at 2 h after injection) in B16/F1 melanoma-bearing mice, and the flank melanoma tumors were clearly imaged by micro-SPECT/CT. Nontarget organ uptakes were considerably lower except for the kidneys. B16/F10 pulmonary melanoma metastases were also clearly visualized by micro-SPECT/CT using (99m)Tc-(Arg(11))CCMSH or (111)In-DOTA-Re(Arg(11))CCMSH as the imaging probe. (99m)Tc-(Arg(11))CCMSH exhibited images with greater resolution of metastatic melanoma lesions compared with (111)In-DOTA-Re(Arg(11))CCMSH.
  
  
  CONCLUSIONS
  The favorable tumor imaging properties of (99m)Tc-(Arg(11))CCMSH and (111)In-DOTA-Re(Arg(11))CCMSH highlighted their potential as novel probes for primary and metastatic melanoma detection.
authors.affiliation: College of Pharmacy, University of New Mexico, Albuquerque, New Mexico, USA.
authors.forename: Yubin
authors.initials: Y
authors.lastname: Miao
authors.forename: Katherine
authors.initials: K
authors.lastname: Benwell
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Quinn
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D007205:Indium Radioisotopes; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008545:Melanoma / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D008546:Melanoma, Experimental; D051379:Mice; D008810:Mice, Inbred C57BL; D008956:Models, Chemical; D009362:Neoplasm Metastasis; D010455:Peptides / Q000737:chemistry*; D013667:Technetium; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D000521:alpha-MSH / Q000378:metabolism*
chemical_list: D007205:Indium Radioisotopes; D010455:Peptides; D000521:alpha-MSH; D013667:Technetium