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Τhe Epidermal Growth Factor Receptor tyrosine kinase inhibitor (EGFR-TKI) 6-amino-4-[(3-bromophenyl) amino]quinazoline was derivatized with 6-bromohexanoyl-chloride and coupled with the tridentate chelating agents N-(2-pyridylmethyl) aminoethyl acetic acid (PAMA) and <i>L</i>(+)-cysteine bearing the donor atom set NNO and SNO, respectively. The rhenium precursors ReBr(CO)₅ and <i>fac</i>-[NEt₄]₂[ReBr₃(CO)₃] were used for the preparation of the Re complexes <i>fac</i>-[Re(NNO)(CO)₃] (<b>5a</b>) and <i>fac</i>-[Re(SNO)(CO)₃] (<b>7a</b>) which were characterized by NMR and IR spectroscopies. Subsequently, the new potential EGFR inhibitors were labeled with the <i>fac</i>-[^99mTc(CO)₃]⁺ core in high yield and radiochemical purity (>90%) by ligand exchange reaction using the <i>fac</i>-[^99mTc][Tc(OH₂)₃(CO)₃]⁺ precursor. The radiolabeled complexes were characterized by comparative HPLC analysis with the analogous rhenium (Re) complexes as references. In vitro studies in the A431 cell lines showed that both ligands and Re complexes inhibit A431 cell growth. Complex <b>5a</b> demonstrated the highest potency (IC₅₀ = 8.85 ± 2.62 μM) and was further assessed for its capacity to inhibit EGFR autophosphorylation, presenting an IC₅₀ value of 26.11 nM. Biodistribution studies of the ^99mTc complexes in healthy mice showed high in vivo stability for both complexes and fast blood and soft tissue clearance with excretion occurring via the hepatobiliary system.