: Integrin αβ plays a crucial role in tumor angiogenesis and cancer progression, making it a key target for radiolabeled probes used in imaging and therapy. A previously developed probe, [I]bcRGD, exhibited high selectivity for αβ but limited tumor accumulation due to rapid blood clearance. This study aimed to address this issue through two strategies: (1) conjugating albumin-binding molecules to enhance systemic circulation and (2) dimerizing RGD peptides to improve binding affinity via multivalency effects. : Three [I]bcRGD derivatives were synthesized: [I]bcRGD (with palmitic acid), [I]bcRGD (with 4-(-iodophenyl)butyric acid), and [I]bcRGD (a dimeric bicyclic RGD peptide). Their physicochemical properties, αβ-selectivity, albumin-binding capacity, and biodistribution were assessed in vitro and in vivo using tumor-bearing mice. Tumor models included αβ-high U-87 MG and αβ-low A549 xenografts. : [I]bcRGD and [I]bcRGD exhibited prolonged blood retention (30-fold and 55-fold vs. [I]bcRGD, respectively) and increased tumor accumulation (3.9% ID/g and 3.6% ID/g at 2 h, respectively). Despite improved systemic circulation, tumor-to-blood ratios remained low (<1), indicating limited tumor retention. [I]bcRGD achieved significantly greater tumor accumulation (4.2% ID/g at 2 h) and favorable tumor-to-blood (22) and tumor-to-muscle (14) ratios, with a 5.4-fold higher uptake in U-87 MG tumors compared to A549 tumors. : Dimerization was more effective than albumin binding in enhancing bcRGD's tumor-targeting potential. The dimeric probe demonstrated improved tumor accumulation, favorable pharmacokinetics, and preserved integrin selectivity. These findings provide a foundation for further structural optimization of bicyclic RGD peptides for integrin αβ-targeted imaging and therapy applications.