PET and Radiopharmaceutical Therapy Isotopes Reference

The right radionuclide is the foundation of every PET scan and radiopharmaceutical therapy (RPT) treatment, and each isotope's half-life, emission type, and energy directly determine image quality, treatment delivery, occupational dose, and the radiation safety procedures a department must follow. F-18, Ga-68, and Cu-64 are positron emitters used for PET imaging; Lu-177, Ra-223, and Ac-225 are particulate emitters used for targeted therapy. This guide is the foundational isotope reference for the PhysicsPulse nuclear medicine series, and it underpins our more detailed shielding work in the PET/CT shielding calculations guide and the RPT shielding guide for Lu-177, Ra-223, and Ac-225 therapy.

At Diagnostic Radiation Physics Services (DRPS), our board-certified medical physicists support nuclear medicine and PET/CT programs across Florida, Maryland, Virginia, Washington DC, California, and Nevada, where isotope selection drives both compliance obligations and day-to-day workflow.

Introduction

Each isotope carries a distinct combination of half-life, emission type, and radiation energy that determines image quality, treatment delivery, occupational exposure, and the radiation safety procedures a department must follow. This guide summarizes the most common PET and RPT isotopes—F-18, Ga-68, Cu-64, Lu-177, Ra-223, and the emerging targeted alpha-therapy isotope Ac-225—and the physics and safety principles that govern their use.

Two technology trends make this reference more relevant than ever. First, the rise of theranostics has tied diagnostic and therapeutic radionuclides together: a Ga-68 PET scan now routinely selects patients for Lu-177 therapy using the same targeting molecule. Second, targeted alpha therapy (Ra-223 today, Ac-225 increasingly) is expanding the radiation safety conversation from penetrating photons toward contamination control and decay-chain management. Understanding the underlying isotope physics is what lets a technologist, physicist, or administrator move confidently between these worlds.

Topic Explanation: Why Isotope Physics Matters in PET and RPT

Isotope physics matters because half-life, emission type, and photon energy directly translate into clinical performance and safety controls. Modern nuclear medicine relies on carefully selected radionuclides for both diagnostic imaging and targeted therapy, and each property has practical consequences:

• Half-life sets the production model (on-site cyclotron, generator, or centralized supplier), scheduling windows, and how long waste stays radioactive.
• Emission type (positron, beta, alpha, gamma) determines whether the dominant hazard is penetrating photons or surface contamination, and therefore which shielding and PPE strategy applies.
• Radiation energy influences image quality, shielding thickness, and technologist dose during dose handling and injection.

Understanding these properties helps technologists optimize workflow, ensure regulatory compliance, and minimize occupational exposure while delivering safe and effective patient care.

Key terms

• Positron range: the average distance a positron travels in tissue before it annihilates. Longer positron range blurs PET resolution because annihilation does not occur exactly at the tracer location.
• Branching ratio: the fraction of decays that proceed by a particular mode or emit a particular photon. An isotope can decay by more than one path, and only some paths produce imageable photons.
• Specific gamma-ray (exposure-rate) constant: the dose rate per unit activity at a fixed distance from a point source, used to estimate unshielded dose. Published values are anchored to decay data such as ICRP Publication 107. ¹²
• Theranostic pair: chemically matched diagnostic and therapeutic radionuclides delivered on the same targeting vector, so the diagnostic scan predicts the therapeutic dose distribution.

Isotope Reference Table

The table below consolidates the key physical, clinical, and radiation safety properties of the isotopes covered in this guide. Half-lives and the principal emissions for F-18, Ga-68, Cu-64, Lu-177, and Ra-223 are the values used throughout this post; values for Ac-225 and the supporting decay-mode and energy detail are drawn from ICRP Publication 107 and allied decay-data compilations and should be verified against the dataset your facility adopts. ¹²⁸

The table is a quick-reference starting point, not a substitute for the decay-data source your radiation safety program formally adopts. For shielding decisions, the RPT shielding guide and PET/CT shielding guide carry these numbers into facility-specific calculations.

Common PET Imaging Isotopes

PET imaging isotopes are positron emitters: each positron annihilates with an electron to produce two 511 keV photons emitted ~180° apart, which the scanner detects in coincidence. The three most common clinical agents are F-18, Ga-68, and Cu-64. The choice among them is governed by half-life (which sets supply logistics) and positron energy (which sets spatial resolution).

Fluorine-18 (F-18) – FDG, Pylarify

• Half-life: 109.8 minutes
• Decay mode: Positron emission → 511 keV annihilation photons
• Clinical use:
  • FDG: Oncology, neurology, infection imaging
  • Pylarify (piflufolastat F-18): Prostate cancer imaging

Physics and Safety Considerations: F-18 provides excellent image quality due to its short positron range and a half-life long enough to allow distribution from a regional cyclotron yet short enough to limit residual activity. Its high-energy 511 keV annihilation photons require proper syringe shielding, typically tungsten, to reduce technologist exposure during dose handling and injection. F-18 also decays by a small fraction of electron capture, but the imageable signal and the dominant occupational hazard both come from the 511 keV annihilation photons. The short positron range is precisely why F-18 remains the resolution benchmark for oncologic PET.

Gallium-68 (Ga-68) – NETSPOT, Locametz

• Half-life: 67.7 minutes
• Decay mode: Positron emission
• Clinical use: Neuroendocrine tumor imaging (NETs), PSMA imaging

Physics and Safety Considerations: Ga-68's shorter half-life allows rapid decay but requires precise coordination between preparation and imaging. It is often produced from a germanium-68/gallium-68 (Ge-68/Ga-68) generator, making it accessible without an on-site cyclotron. Radiation exposure from waste and contaminated materials decreases quickly because of the rapid decay. One physics trade-off worth knowing: Ga-68's positron energy is substantially higher than F-18's, giving it a longer positron range and therefore slightly coarser intrinsic spatial resolution—usually a clinically acceptable cost for the convenience of generator-based supply. Ga-68 is also the diagnostic half of the most established theranostic pairs: a Ga-68 DOTATATE or Ga-68 PSMA scan selects and maps disease before Lu-177 therapy on the same molecule.

Copper-64 (Cu-64) – Detectnet

• Half-life: 12.7 hours
• Decay mode: Positron emission and beta decay
• Clinical use: Neuroendocrine tumor imaging

Physics and Safety Considerations: Cu-64's longer half-life allows centralized production and flexible scheduling, an advantage for sites without local radiopharmacy capacity. However, waste and contaminated materials remain radioactive longer and must follow proper decay-in-storage procedures before disposal. Cu-64 is unusual among clinical PET tracers because it decays by three competing routes—positron emission, beta-minus emission, and electron capture—so only a minority of decays produce the 511 keV photons used for imaging, while the beta-minus component contributes a small therapeutic-style dose locally. For radiation safety, the practical consequences are the same as any positron emitter at the point of handling (511 keV photons), plus a longer waste-management tail than F-18 or Ga-68.

Common Radiopharmaceutical Therapy (RPT) Isotopes

Radiopharmaceutical therapy isotopes deliver a cytotoxic dose to targeted tissue using particulate radiation—beta particles or alpha particles—rather than relying on imaging photons. The dominant clinical examples are Lu-177 and Ra-223, with Ac-225 emerging as a targeted alpha therapy.

Lutetium-177 (Lu-177) – Lutathera, Pluvicto

• Half-life: 6.7 days
• Decay mode: Beta emission with gamma emissions
• Clinical use:
  • Lutathera: Neuroendocrine tumors
  • Pluvicto: Prostate cancer

Physics and Safety Considerations: Lu-177 emits beta particles that deliver therapy and gamma photons that allow post-therapy imaging and dosimetry. Because patients remain measurably radioactive for several days, technologists must minimize close-contact time, follow proper radiation safety protocols, and provide patient release instructions consistent with NRC Regulatory Guide 8.39. For external radiation protection, the relevant emissions are the 113 keV and 208 keV gamma photons; the beta particles are largely absorbed within the patient. Lutathera's pivotal NETTER-1 trial established Lu-177 DOTATATE for midgut neuroendocrine tumors, and the VISION trial established Lu-177 PSMA (Pluvicto) for metastatic castration-resistant prostate cancer—two landmark results that drove the rapid expansion of beta-emitting RPT programs. ⁹¹⁰ Because Lu-177 emits an imageable gamma alongside its therapeutic beta, it is the therapeutic half of a true theranostic pair: the same DOTATATE or PSMA vector can be labeled with Ga-68 for imaging and Lu-177 for treatment. We cover the quantitative side of this in our Lu-177 theranostics dosimetry guide.

Radium-223 (Ra-223) – Xofigo

• Half-life: 11.4 days
• Decay mode: Alpha emission
• Clinical use: Treatment of bone metastases in prostate cancer

Physics and Safety Considerations: Alpha particles deposit very high energy over an extremely short range. External exposure risk is therefore low, but contamination control is critical. Internal exposure must be avoided through proper handling, PPE use, and contamination surveys, because alpha-emitting contamination is hazardous if inhaled or ingested. Ra-223 behaves as a calcium mimetic, concentrating at sites of high bone turnover, which is why it targets osteoblastic bone metastases with minimal marrow dose. Its survival benefit in metastatic castration-resistant prostate cancer was established in the ALSYMPCA trial. ¹¹ Clinically and from a safety standpoint, the key Ra-223 message is that body fluids—urine, feces, blood—are the principal contamination pathway, so the radiation safety program emphasizes spill response and hygiene instructions over structural shielding, a distinction developed in the RPT shielding guide.

Actinium-225 (Ac-225) – Targeted Alpha Therapy

• Half-life: 9.9 days
• Decay mode: Alpha emission through a multi-step decay chain (daughters include Fr-221 and Bi-213)
• Clinical use: Investigational and specialty targeted alpha therapy (for example, Ac-225 PSMA and Ac-225 DOTATATE programs)

Physics and Safety Considerations: Ac-225 is an alpha-emitting therapy, but it is not "just another Ra-223." Its decay chain delivers four net alpha particles to the target while passing through radioactive daughters that emit photons—Fr-221 and Bi-213 in particular—which can create a measurable external photon field near sources, waste, and handling areas. That changes the radiation safety problem: an Ac-225 program needs alpha contamination control like Ra-223, plus a photon-aware shielding and waste-storage review more like a beta/gamma emitter once daughters have grown in. Because Ac-225 data are still being consolidated across decay-data compilations, facilities should anchor any numeric assumption (half-life, daughter photon yield, exposure-rate constant) to a current reference such as ICRP Publication 107 or the LNHB decay tables before relying on it. ¹⁸ The shielding implications are developed in detail in the RPT shielding guide for Lu-177, Ra-223, and Ac-225 therapy.

Key Technical Principles

The radiation safety strategy for any radiopharmaceutical follows directly from its emission type. Match the control to the hazard: penetrating photons demand shielding, while particulate emitters demand contamination control. The quantitative tools below—the decay law, decay-in-storage arithmetic, and the inverse-square law—convert isotope properties into the practical decisions a department makes every day.

The decay law and half-life

All radioactive decay follows the same exponential law. For an initial activity $A_0$, the activity remaining after time $t$ is:

where the decay constant $\lambda$ is fixed by the half-life $T_{1/2}$:

This single relationship explains the operational personality of each isotope. For F-18 ($T_{1/2}=109.8$ min), $\lambda \approx 0.00631{\text{min}}^{-1}$, so a dose drawn 90 minutes before injection has decayed to $A(90)/A_0=e^{-0.00631\times 90}\approx 0.57$—roughly 57% of the calibrated activity remains, which is why F-18 scheduling is unforgiving. For Lu-177 ($T_{1/2}=6.7$ d), $\lambda \approx 0.103{\text{d}}^{-1}$, so a treated patient still carries about $e^{-0.103\times 1}\approx 90\%$ of the administered activity one day after therapy—the physical basis for patient release instructions under NRC Regulatory Guide 8.39.

Decay-in-storage: the "10 half-lives to background" rule

Isotopes with longer half-lives, such as Cu-64 and Lu-177, require decay-in-storage before disposal. A common rule of thumb is to hold material for at least 10 half-lives and confirm activity is indistinguishable from background before release. The factor of 10 half-lives is not arbitrary—it follows directly from the decay law:

After $n$ half-lives, $A/A_0=2^{-n}$. For $n=10$:

so the activity falls to under 0.1% of its starting value—generally enough to reach background for typical clinical activities, which is why 10 half-lives is the conventional hold target. The practical hold time scales with half-life: 10 half-lives of Cu-64 (12.7 h) is about 5.3 days, while 10 half-lives of Lu-177 (6.7 d) is about 67 days. Short-lived F-18 and Ga-68, by contrast, reach background within a working day, which is why decay-in-storage is mainly a Cu-64, Lu-177, Ra-223, and Ac-225 concern. Regardless of the rule of thumb, the regulatory requirement under 10 CFR 35 is to survey and confirm the material is indistinguishable from background before disposal.

The inverse-square law and a worked dose-rate example

Radiation dose rate from a point source falls with the square of distance. For an unshielded point source of activity $A$ with specific gamma-ray (exposure-rate) constant $\Gamma$, the dose rate at distance $d$ is:

Doubling the distance therefore cuts the dose rate to one quarter—the single most cost-free dose-reduction tool a technologist has. As a worked example using the AAPM TG-108 effective dose-rate constant for an F-18 patient, $\Gamma =0.092\mu \text{Sv}\cdot {\text{m}}^2\cdot {\text{MBq}}^{-1}\cdot {\text{h}}^{-1}$, a 370 MBq injected patient produces an unshielded dose rate at 1 m of: ³

Step back to 3 m and the inverse-square law drops that to:

a nearly ninefold reduction from distance alone, before any shielding. This is the arithmetic behind positioning uptake chairs and recovery areas thoughtfully rather than reaching first for lead. For isotope-specific exposure-rate constants beyond F-18, use a verified compilation such as Smith and Stabin's tabulation built on ICRP Publication 107 decay data rather than assuming one constant fits every radionuclide. ¹²

Shielding Requirements

Different radiation types require different shielding approaches:

• Positron emitters (F-18, Ga-68, Cu-64): Tungsten or lead syringe shields to attenuate 511 keV annihilation photons.
• Beta emitters (Lu-177): Low-atomic-number acrylic shielding stops beta particles while minimizing bremsstrahlung production; high-Z material would increase bremsstrahlung.
• Alpha emitters (Ra-223, Ac-225): Focus on contamination control rather than external shielding, since alpha particles are stopped by a sheet of paper or the outer layer of skin—but remember that Ac-225's photon-emitting daughters can still warrant localized shielding around sources and waste.

For department-level layout and barrier design, our PET/CT shielding calculations guide and RPT shielding guide for Lu-177, Ra-223, and Ac-225 therapy walk through the calculations in detail, and our overview of lead shielding design principles covers the underlying barrier physics.

Contamination Prevention

Technologists should:

• Use syringe shields during preparation and administration
• Use absorbent pads during injection
• Perform routine contamination surveys
• Follow proper waste handling procedures

Effective contamination control depends on the right survey instruments and response protocols; see our companion posts on decontamination best practices in nuclear medicine and choosing the right radiation survey meter.

Patient and Staff Protection (ALARA)

Radiation exposure is minimized using the three core ALARA ("As Low As Reasonably Achievable") principles:

• Time: Minimize time spent near radioactive patients and sources
• Distance: Maximize distance whenever possible (dose rate falls with the inverse square of distance, as shown above)
• Shielding: Use appropriate shielding matched to the emission type

Technologists play a critical role in maintaining these protections during imaging and therapy procedures. Routine personnel dosimetry confirms that these controls are working; see our guide to occupational exposure monitoring.

Clinical Impact

Isotope physics is not an academic detail—it shapes scheduling, throughput, and patient management every day:

• Workflow and scheduling: Short-lived isotopes (Ga-68, F-18) demand tight coordination between preparation and imaging, while longer-lived isotopes (Cu-64) tolerate flexible, centralized supply.
• Image quality: F-18's short positron range supports high spatial resolution, making it the workhorse for oncologic PET, while Ga-68's higher positron energy trades a little resolution for generator convenience.
• Theranostics: The Ga-68/Lu-177 pairing lets a single targeting molecule (DOTATATE or PSMA) be imaged with a positron emitter and treated with a beta emitter, so the diagnostic scan predicts where the therapeutic dose will go.
• Therapy and follow-up: Lu-177's accompanying gamma emissions enable post-therapy imaging and patient-specific dosimetry, while Ra-223's and Ac-225's alpha emissions concentrate dose at target sites with minimal marrow exposure.
• Patient release: Therapy patients may require release instructions and, in some cases, brief activity restrictions, all driven by the isotope's half-life and emission profile and documented under NRC Regulatory Guide 8.39.

PET uptake time, which depends directly on tracer half-life and biodistribution kinetics, is another place where isotope physics meets daily workflow; we cover it in our PET uptake time guide.

Practical Tips for Technologists

• Plan around the clock: Build draw, transport, and injection schedules around half-life, especially for Ga-68 and F-18, where a 60–90 minute delay can consume a large fraction of the calibrated activity.
• Match the shield to the emission: Tungsten/lead for positron emitters, acrylic for Lu-177 betas, contamination control for Ra-223 and Ac-225—and remember Ac-225 daughters may justify localized photon shielding.
• Use distance first: Before reaching for lead, step back; the inverse-square law makes distance the cheapest dose reduction available.
• Survey deliberately: Perform contamination surveys after every RPT administration and at end of day, and document results.
• Segregate waste by isotope: Label and store decay-in-storage waste separately so half-life-based release decisions stay traceable, and remember the hold time scales with half-life (days for Cu-64, weeks for Lu-177).
• Mind cumulative dose: Apply time-distance-shielding consistently; small habits compound across a high-volume PET or therapy schedule.

Regulatory Considerations

Medical use of these isotopes is governed by federal and state radiation regulations. In NRC Agreement States and NRC-regulated jurisdictions alike, the medical use of byproduct material falls under 10 CFR 35, with general radiation protection standards in 10 CFR 20. Patient release after therapy with Lu-177, Ra-223, or Ac-225 follows NRC Regulatory Guide 8.39. Program-specific licensing expectations are consolidated in NRC NUREG-1556, Volume 9, and Ra-223 programs have dedicated guidance in NRC FSME-13-002.

Jurisdiction matters and is easy to get wrong. Florida, Maryland, Virginia, California, and Nevada are NRC Agreement States that license medical use of byproduct material under their own radiation-control programs, while Washington, DC is regulated directly by the NRC (not an Agreement State). State requirements layer on top of federal rules: in Florida, for example, nuclear medicine programs must comply with Florida 64E-5 (Control of Radiation Hazard Regulations), administered by the Florida Department of Health. DRPS supports clients navigating these obligations across Florida, Maryland, Virginia, Washington DC, California, and Nevada. For deeper guidance, see Florida radiation safety requirements for imaging centers, our NRC radioactive material license guide, and how to avoid common radiation safety violations.

Frequently Asked Questions (FAQs)

What is the half-life of Fluorine-18 (F-18)?

Fluorine-18 has a half-life of 109.8 minutes. It is used in FDG and Pylarify for PET imaging and requires tungsten syringe shielding to reduce technologist exposure from its 511 keV annihilation photons.

Which isotope is used in Pluvicto and Lutathera?

Lutetium-177 (Lu-177) is used in both Pluvicto (prostate cancer) and Lutathera (neuroendocrine tumors). It has a 6.7-day half-life and emits beta particles for therapy plus gamma photons usable for imaging and dosimetry.

What are common PET imaging isotopes besides F-18?

Gallium-68 (Ga-68) is used for neuroendocrine tumor and PSMA imaging, and Copper-64 (Cu-64) is used for neuroendocrine imaging. Ga-68 has a 67.7-minute half-life; Cu-64 has a 12.7-hour half-life.

Why does Radium-223 (Xofigo) require strict contamination control?

Ra-223 decays by alpha emission. Alpha particles have a very short range, so external exposure is low, but internal exposure must be prevented through careful handling, PPE, and contamination surveys.

How does isotope half-life affect radioactive waste disposal?

Longer-lived isotopes such as Cu-64 and Lu-177 must be held in decay-in-storage until they meet release limits, while short-lived isotopes like Ga-68 and F-18 decay to background quickly. Decay-in-storage practices are governed by 10 CFR 35 and equivalent state rules. A common target is 10 half-lives, after which activity has fallen to about 1/1024 of its starting value.

What makes an isotope a good theranostic pair?

A theranostic pair uses chemically matched diagnostic and therapeutic radionuclides on the same targeting molecule, so imaging predicts where therapy will deposit dose. Ga-68/Lu-177 (used in DOTATATE and PSMA agents) is the classic example, pairing a Ga-68 positron emitter for PET with a Lu-177 beta emitter for treatment.

Why is Ac-225 considered different from other alpha-emitting therapies?

Actinium-225 is a targeted alpha therapy with a 9.9-day half-life whose decay chain produces several radioactive daughters, including Fr-221 and Bi-213, that emit photons. Unlike Ra-223, Ac-225 can create a measurable external photon field near sources and waste, so it needs both alpha contamination control and a photon-aware shielding review.

Key Takeaways

• F-18 (109.8-minute half-life) is the workhorse PET isotope, used in FDG and Pylarify, and requires tungsten syringe shielding for its 511 keV photons; its short positron range gives PET its best spatial resolution.
• Ga-68 (67.7-minute half-life) is generator-produced and enables PSMA and neuroendocrine PET without an on-site cyclotron, while Cu-64 (12.7-hour half-life) supports centralized supply and decays by three competing routes.
• Lu-177 (6.7-day half-life) delivers beta therapy in Lutathera and Pluvicto and emits 113 keV and 208 keV gamma photons usable for post-therapy imaging and dosimetry, making it the therapeutic half of a Ga-68/Lu-177 theranostic pair.
• Ra-223 (11.4-day half-life) is an alpha emitter used for bone metastases; its hazard is contamination via body fluids, not external exposure. Ac-225 (9.9-day half-life) is an emerging targeted alpha therapy whose decay-chain daughters add a photon component requiring extra shielding attention.
• Shielding strategy follows emission type: lead/tungsten for positron photons, acrylic for Lu-177 betas, and contamination control for Ra-223 and Ac-225 alphas; distance and the inverse-square law are the cheapest dose-reduction tools.
• Longer-lived isotopes (Cu-64, Lu-177, Ra-223, Ac-225) require decay-in-storage before disposal under 10 CFR 35 and state rules such as Florida 64E-5, with hold times of roughly 10 half-lives.

How DRPS Can Help

DRPS provides board-certified diagnostic and nuclear medical physics support—radiation safety program development, radiation shielding design, decay-in-storage and waste protocols, ALARA optimization, and regulatory compliance for NRC and Agreement State requirements. Whether you are launching a PSMA PET service or expanding a Lu-177, Ra-223, or Ac-225 therapy program in Florida, Maryland, Virginia, Washington DC, California, or Nevada, our physicists help you align isotope handling with both safety best practices and the applicable regulations. New and expanding programs can also pair this work with radiation safety officer consulting and radioactive material license support. Contact DRPS to discuss your program.

Conclusion

Each PET and therapeutic isotope has unique physical properties that directly influence imaging performance, radiation exposure, and safety protocols. Understanding isotope half-life, emission type, and clinical application allows technologists to optimize procedures, protect themselves and others, and ensure safe and effective patient care. As theranostics and targeted alpha therapy continue to expand—from established Ga-68/Lu-177 pairs to emerging Ac-225 programs—isotope knowledge remains the essential foundation of modern nuclear medicine practice.

Related Resources

• PET/CT shielding calculations guide
• RPT shielding for Lu-177, Ra-223, and Ac-225
• Lu-177 theranostics dosimetry
• Lead shielding design principles
• Nuclear medicine decontamination best practices
• Radiation shielding design
• Radiation Safety Officer consulting
• Radioactive material license support

References

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2. Smith DS, Stabin MG. Exposure rate constants and lead shielding values for over 1,100 radionuclides. Health Physics. 2012;102(3):271-291. doi:10.1097/HP.0b013e318235153a. PubMed
3. Madsen MT, Anderson JA, Halama JR, et al. AAPM Task Group 108: PET and PET/CT shielding requirements. Medical Physics. 2006;33(1):4-15. doi:10.1118/1.2135911. aapm.onlinelibrary.wiley.com
4. National Institute of Standards and Technology. Radionuclide Half-Life Measurements and Decay Data resources for fluorine-18 and other radionuclides. nist.gov
5. U.S. Nuclear Regulatory Commission. 10 CFR Part 20: Standards for Protection Against Radiation. ecfr.gov
6. U.S. Nuclear Regulatory Commission. 10 CFR Part 35: Medical Use of Byproduct Material. ecfr.gov
7. U.S. Nuclear Regulatory Commission. Regulatory Guide 8.39: Release of Patients Administered Radioactive Material. nrc.gov
8. Laboratoire National Henri Becquerel. Ac-225 decay data tables. lnhb.fr
9. Strosberg J, El-Haddad G, Wolin E, et al. Phase 3 trial of ¹⁷⁷Lu-Dotatate for midgut neuroendocrine tumors. New England Journal of Medicine. 2017;376(2):125-135. doi:10.1056/NEJMoa1607427. PubMed
10. Sartor O, de Bono J, Chi KN, et al. Lutetium-177–PSMA-617 for metastatic castration-resistant prostate cancer (VISION). New England Journal of Medicine. 2021;385(12):1091-1103. doi:10.1056/NEJMoa2107322. PubMed
11. Parker C, Nilsson S, Heinrich D, et al. Alpha emitter radium-223 and survival in metastatic prostate cancer (ALSYMPCA). New England Journal of Medicine. 2013;369(3):213-223. doi:10.1056/NEJMoa1213755. PubMed
12. U.S. Nuclear Regulatory Commission. NUREG-1556, Volume 9, Revision 3: Consolidated Guidance About Materials Licenses — Program-Specific Guidance About Medical Use Licenses. nrc.gov