In this investigation, synthetic design strategies were employed to modify the structure of an SSTR2-targeted peptide based on TOC to allow for the inclusion of Pb isotopes and to determine if these structural modifications could improve key performance metrics (e.g., in vitro binding affinity and internalization; in vivo tumor targeting and renal clearance rate), with a goal of enhancing the overall efficacy and tolerability of the radiopharmaceutical. This evidence concerns the gene SSTR2 and neoplasm.