This invention relates to kits for tumor imaging and methods for preparing the kits using a composition having the structureHis Ser Asp Gly lle Phe Thr Asp Ser Tyr Ser Arg Tyr Arg Lys Gln Met Ala Val Lys Lys Tyr Leu Ala Ala Val Leu yAba Lys (R) (SEQ ID NO:1) wherein the y amino group of the lysine residue is coupled to a chelator disclosed in this application.