The landscape of peptide receptor radionuclide therapy (PRRT) is shifting toward 212Pb, which has demonstrated ORRs in patients refractory to standard beta-emitters.1,2 First-in-human studies confirm the feasibility and tolerability of this approach, with disease stabilization observed even in heavily pretreated populations.3 The potent cytotoxicity of alpha particles results from dense ionization tracks, causing irreparable DNA damage.4,5

While effective against resistant clones, this mechanism increases the risk to the pituitary gland, which expresses the constitutively active somatostatin receptor subtype 2 (SSTR2). Long-term follow-up after beta-PRRT has established baseline rates of delayed hypopituitarism (≈8%) and therapy-related myeloid neoplasms (2%–3%).6,7 Transitioning to routine practice requires a structured protocol—one that translates radiobiological principles into a practical roadmap. The protocol must embed risk mitigation at every step of the clinical pathway—from patient selection to lifetime follow-up.

Recent advances in quantitative SPECT imaging and dosimetry for 203Pb/212Pb now make personalized treatment planning clinically feasible.8–10 As the radiotheranostic field evolves toward radiohybrid systems and antibody-mimetic proteins with enhanced specificity and faster clearance, 212Pb is positioned as a primary successor for patients who fail beta-emitting therapies.11 Comprehensive reviews of the radiotheranostic landscape confirm that this principle is now gaining recognition across the field.12

For these patients and others who are refractory to standard-of-care treatment, this article provides a practice-oriented roadmap that translates complex radiobiological principles into a visually guided, step-by-step operational plan that can be implemented immediately in the multidisciplinary radio-oncology medical center. This plan or framework is built on 4 actionable pillars—advanced biomarker selection, personalized dosimetry, prospective safety monitoring, and registry science—and culminates in a consolidated Clinical Decision Pathway (see Table 2, infra).
Our objective is to equip clinicians with the specific tools and protocols needed to harness the formidable power of targeted alpha therapy (TAT) while unequivocally prioritizing patient safety.

The fundamental biophysical mechanism that confers this agent’s high potency—alpha particle-induced DNA damage—is illustrated in Figure 1. Because an alpha particle is actually a helium nucleus (2 protons and 2 neutrons), it is much heavier than a lone proton, which is why it acts like a “cannonball,” causing that clustered, irreparable double-strand break, as illustrates​​​​​​d in Figure 1. High-resolution conceptual modeling illustrates the “bulkier” clustered damage characteristic of alpha radiation compared with the single-strand nicks typically associated with beta particles.