# Authorized user shortage for radionuclide therapy

Source: https://nuclide.cc/bottlenecks/b-authorized-user-shortage/  
Nuclide record `b-authorized-user-shortage` (Bottleneck). Data CC BY-NC 4.0, attribute "Data from Nuclide (nuclide.cc)"; commercial use needs a licence.

## TL;DR

In the US, only specially trained doctors are legally allowed to give radioactive cancer treatments. Whether there are enough of these doctors to keep up with demand is genuinely disputed: regulators and physician groups have looked at the numbers and reached different conclusions.

## Summary

Under US NRC rule 10 CFR 35.390, only a physician who has completed the required training and experience -- either full nuclear medicine/radiation oncology board certification, or an alternate pathway of about 700 hours (roughly four months) of structured training -- can become an 'Authorized User' (AU) and administer radionuclide therapies requiring a written directive. Since 2017-2018 the NRC's Advisory Committee on the Medical Uses of Isotopes (ACMUI) has repeatedly examined whether a future AU shortage will bottleneck access to radioligand therapy, prompted by the approval of 177Lu-DOTATATE and the shrinking pipeline of US-trained nuclear medicine physicians.

The evidence is contested. A 2019 JNM editorial estimated the existing board-certified US nuclear medicine physician workforce at around 1,200, with 50-60 new ABNM diplomates entering annually, and projected that meeting demand for 150,000-200,000 radionuclide therapy cycles a year (roughly 50,000 patients at four cycles each) would need about 150 dedicated theranostic centres -- a number the authors argued the existing and incoming workforce could support, so long as radiologists and radiation oncologists trained under the alternate pathway are counted. The NRC's own ACMUI subcommittee concluded in 2018-2019 that there was 'no objective data to confirm an authorized user shortage' and did not recommend creating a lower-training limited-scope AU pathway.

Whatever the physician-supply numbers show nationally, the practical effect for patients is the same: AU status is concentrated in nuclear medicine, radiology and radiation oncology, not in the medical oncology clinics that manage most prostate cancer and neuroendocrine tumour patients, so referral to a licensed, AU-staffed centre remains an extra step in every patient's pathway.

## Fields

- Kind: Bottleneck
- Last checked: 2026-09-22
- Tags: workforce; regulation; authorized user
- Stage: people-culture
- Severity: moderate
- Metrics: Training hours required for the 10 CFR 35.390 alternate Authorized User pathway: 700 hours (~4 months); Estimated US board-certified nuclear medicine physician workforce (2019): ~1,200, plus 50–60 new ABNM diplomates/year; Estimated dedicated theranostic centres needed for projected US radionuclide-therapy demand: ~150 centres for 150,000–200,000 cycles/year; NRC ACMUI subcommittee finding on AU shortage evidence: "No objective data to confirm an authorized user shortage" (2018–19)
- Causes: Authorized User status requires either full nuclear medicine/radiation oncology board certification or a separate, lengthy alternate training pathway that most medical oncologists never complete.; The physicians who see most prostate cancer and neuroendocrine tumour patients (medical oncologists, urologists) are usually not the physicians licensed to administer the radioactive therapy itself.; Whether a genuine national AU shortage exists is disputed between professional societies and NRC advisory findings, which has slowed any policy resolution either way.

## Sources

- JNM editorial: Delivering radionuclide therapies requires extensive training and competence: https://jnm.snmjournals.org/content/60/1/1
- NRC Advisory Committee on the Medical Uses of Isotopes, transcript on AU shortage evidence: https://www.nrc.gov/docs/ML1907/ML19077A112.pdf
- NRC: Authorized Individuals (10 CFR Part 35 training requirements): https://www.nrc.gov/materials/miau/med-use-toolkit/auth-individuals
- SNMMI Theranostics Stakeholders Summit white paper (2025): https://snmmi.org/common/Uploaded%20files/News/Theranostics_Stakeholders_Summit_White_Paper_FINAL_6-2025.pdf

## Connected records

- bottlenecks: [Nuclear medicine technologist and physicist workforce](https://nuclide.cc/bottlenecks/b-nuclear-medicine-workforce/), [Site readiness and referral pathway delays](https://nuclide.cc/bottlenecks/b-site-readiness-referral/)
- isotopes: [Lutetium-177](https://nuclide.cc/isotopes/lu-177/)
- technologies: [Peptide receptor radionuclide therapy (PRRT)](https://nuclide.cc/technologies/prrt/), [PSMA PET](https://nuclide.cc/technologies/psma-pet/), [Radioligand therapy (beta emitters)](https://nuclide.cc/technologies/radioligand-therapy/)
- institutions: [Society of Nuclear Medicine and Molecular Imaging](https://nuclide.cc/institutions/snmmi/)

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