# Lead-212

Source: https://nuclide.cc/isotopes/pb-212/  
Nuclide record `pb-212` (Isotope). Data CC BY-NC 4.0, attribute "Data from Nuclide (nuclide.cc)"; commercial use needs a licence.

## TL;DR

A radioactive metal that, once inside the body, turns itself into a much more damaging particle-emitter over the following hours. It is being explored as a way to deliver strong, short-range radiation without needing the rarer isotopes used in similar treatments.

## Summary

Lead-212 is itself a beta emitter, but it functions in practice as an in vivo generator of alpha radiation: it decays (half-life 10.64 hours) to bismuth-212 (half-life about 61 minutes), which then decays either directly by alpha emission (to thallium-208) or by a further beta decay to the pure alpha emitter polonium-212. A member of the thorium-232/232U decay series, 212Pb is drawn from generators loaded with its longer-lived parents radium-224 (half-life 3.63 days) or thorium-228 (half-life about 1.9 years).

Its 10.6-hour half-life is long enough to synthesise and ship a labelled radiopharmaceutical but short enough to limit prolonged radiation exposure, and it uses conventional chelation chemistry (unlike some other alpha emitters). 212Pb-DOTAMTATE (AlphaMedix) and other 212Pb-labelled somatostatin and PSMA-targeting agents are in early clinical trials.

Unlike actinium-225, the feedstock chain for 212Pb (natural thorium-232/uranium-232 decay) is not considered scarce: Perspective Therapeutics states its proprietary 224Ra/212Pb generator system and a long-term US DOE supply contract for 228Th could support over 100,000 doses per year, and Orano Med, RadioMedix/Thor Medical and others are commercialising 228Th-based 212Pb generators. Some reviews describe 212Pb supply as having moved from a major constraint to a largely solved production problem, though clinical-scale, GMP-qualified generator throughput is still being industrialised.

## Fields

- Kind: Isotope
- Status: phase-2
- Last checked: 2026-09-22
- Also known as: 212Pb; Pb-212
- Tags: therapy; alpha emitter; in vivo generator

## Sources

- 212Pb: Production Approaches and Targeted Therapy Applications (Pharmaceuticals, 2022): https://pmc.ncbi.nlm.nih.gov/articles/PMC8777968/
- Perspective Therapeutics: Manufacturing & Logistics (VMT-α-GEN Pb-212 generator): https://perspectivetherapeutics.com/technology/manufacturing-logistics
- DOE Isotope Program: Availability of radium-224/lead-212 generators: https://www.isotopes.gov/node/123
- Lead radionuclides for theranostic applications in nuclear medicine (PMC, 2026): https://pmc.ncbi.nlm.nih.gov/articles/PMC12775822/

## Connected records

- drugs: [212Pb-DOTAMTATE](https://nuclide.cc/drugs/alphamedix/), [Lead-212 PSV359](https://nuclide.cc/drugs/pb-212-psv359/), [Lead-212 VMT-alpha-NET](https://nuclide.cc/drugs/pb-212-vmt-alpha-net/)
- trials: [ALPHAMEDIX-02](https://nuclide.cc/trials/alphamedix-02/), [Lead-212 PSV359 Therapy for Patients With Solid Tumors](https://nuclide.cc/trials/nct06710756/), [MC1R-targeted Alpha-particle Monotherapy and Combination Therapy Trial With Nivolumab in Adults With Advanced Melanoma](https://nuclide.cc/trials/nct05655312/), [Study of [212Pb]Pb-DOTAM-MAM279 ([212Pb]Pb-MP0712) in Patients With Small Cell Lung Cancer and Other DLL3 Expressing Solid Tumors](https://nuclide.cc/trials/nct07278479/), [Targeted Alpha-Particle Therapy for Advanced Somatostatin Receptor Type 2 (SSTR2) Positive Tumors](https://nuclide.cc/trials/nct05636618/)
- technologies: [Actinium-225 supply: thorium stocks, accelerators and radium targets](https://nuclide.cc/technologies/actinium-225-supply/), [Alpha-emitter daughter redistribution ('free daughter' problem)](https://nuclide.cc/technologies/alpha-daughter-redistribution/), [Macropa chelation](https://nuclide.cc/technologies/macropa-chelation/), [Peptide receptor radionuclide therapy (PRRT)](https://nuclide.cc/technologies/prrt/), [Targeted alpha therapy](https://nuclide.cc/technologies/targeted-alpha-therapy/), [Therapeutic isotope supply chain (Mo-99, Lu-177, Ac-225)](https://nuclide.cc/technologies/therapy-isotope-supply-chain/)
- isotopes: [Bismuth-213](https://nuclide.cc/isotopes/bi-213/), [Radium-224](https://nuclide.cc/isotopes/ra-224/)
- ideas: [Fund alpha emitters beyond actinium-225: lead-212, terbium-149 and astatine-211](https://nuclide.cc/ideas/idea-reg-alpha-emitter-portfolio/)
- companies: [AdvanCell](https://nuclide.cc/companies/advancell/), [ARTBIO](https://nuclide.cc/companies/artbio/), [Orano Med](https://nuclide.cc/companies/orano-med/), [Perspective Therapeutics](https://nuclide.cc/companies/perspective-therapeutics/), [RadioMedix](https://nuclide.cc/companies/radiomedix/)
- indications: [Neuroendocrine tumours](https://nuclide.cc/indications/neuroendocrine/)
- targets: [Somatostatin receptor 2](https://nuclide.cc/targets/sstr2/)
- terms: [PRRT (peptide receptor radionuclide therapy)](https://nuclide.cc/terms/prrt-term/)
- pairings: [Beta PRRT → alpha PRRT](https://nuclide.cc/pairings/prrt-then-alpha-net/)
- roadmaps: [Alpha-emitter roadmap: radium-223 → 225Ac-PSMA-617 → a phase 3 pipeline](https://nuclide.cc/roadmaps/alpha-therapy-roadmap/), [Radiopharmaceutical roadmap: iodine → lutetium → actinium](https://nuclide.cc/roadmaps/radiopharma-roadmap/), [SSTR theranostics roadmap: octreotide scintigraphy → 68Ga-DOTATATE → 177Lu-DOTATATE → alpha](https://nuclide.cc/roadmaps/sstr-theranostics-roadmap/)

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