Implementing 212Pb-Targeted Alpha Therapy: A Safety-First Theranostic Framework for Clinical Practice

Purpose of Review: With objective response rates (ORR) reaching 50% in early trials, lead-212 ( 212 Pb) targeted alpha therapy (TAT) represents a promising advance for neuroendocrine tumors (NETs). This review translates emerging clinical evidence into a practical, safety-first theranostic framework for nuclear medicine clinicians. Recent Findings: Early-phase data confirm the potency of 212 Pb-TAT, including in patients refractory to beta-emitting PRRT. First-in-human studies of [ 212 Pb]Pb-VMT-α-NET demonstrate favorable tolerability and disease stabilization in heavily pretreated populations. However, high-linear energy transfer (LET) radiation amplifies risks to somatostatin receptor subtype 2 (SSTR2)-expressing normal tissues, specifically the pituitary gland. Historical beta-PRRT data show hypopituitarism (≈8%) and therapy-related myeloid neoplasms (2%–3%)—risks that are likely higher with alpha-emitters. Quantitative imaging and dosimetry using the 203 Pb/ 212 Pb theranostic pair are now clinically feasible. Summary: We propose a 4-step framework: (1) quantitative patient selection using tumor-to-pituitary SUV ratios, (2) mandatory personalized dosimetry using the 203 Pb/ 212 Pb pair, (3) embedded safety monitoring for endocrine/hematologic toxicity, and (4) commitment to registry science for long-term pharmacovigilance. This framework provides a ready-to-use clinical checklist to guide multidisciplinary teams in balancing the potency of alpha therapy with rigorous patient safety protocols.