Patient Release After Radiopharmaceutical Therapy: Complying with 10 CFR 35.75

A patient who has received radiopharmaceutical therapy may be released from the licensee's control if the total effective dose equivalent (TEDE) to any other individual from exposure to that patient is not likely to exceed 5 mSv (0.5 rem) — a dose-based limit set by 10 CFR 35.75, not a residual-activity cutoff.^{1, 2} Because the criterion is a dose to other people, the same administered activity can be releasable for one patient and not for another, and licensees demonstrate compliance using one of three accepted methods from NRC Regulatory Guide 8.39 and NUREG-1556 Volume 9: default activity and dose-rate tables, or patient-specific calculations using the measured dose rate at 1 m and — at their most refined — the patient's measured effective half-life and a realistic occupancy factor.^{2, 3}

When the projected dose to any other individual could exceed 1 mSv (0.1 rem), the licensee must also provide the patient with written radiation safety instructions, and certain releases and breast-feeding scenarios trigger specific recordkeeping under 10 CFR 35.2075.^{1, 4} This guide explains the release criterion, the three demonstration methods and the equations behind them, a worked I-131 example, the written-instruction and recordkeeping requirements, and how the framework applies to the therapies DRPS supports across Florida, Maryland, Virginia, Washington DC, California, and Nevada.

Introduction

Patient release is the single most consequential radiation-safety decision in a radiopharmaceutical therapy program, because it is the point at which a radioactive patient walks out of the controlled environment and into a home, a car, and a community. The regulation that governs it — 10 CFR 35.75 — replaced an older activity-and-dose-rate threshold (the historical 30 mCi / 5 mR/h at 1 m rule) with a modern, dose-based standard in 1997: a patient may be released if the TEDE to any other individual is unlikely to exceed 5 mSv (0.5 rem).^{1, 2} That shift matters because it ties the decision to the quantity that actually drives risk — the dose someone else receives — rather than to a fixed amount of activity in the patient.

The change had a real clinical purpose: it allowed many thyroid-cancer and other therapy patients to be treated and released as outpatients rather than admitted for radiation-isolation, reducing cost and bed pressure while keeping public exposure within a defensible limit.^{2, 5} But "dose-based" also means "calculation-based." A program cannot simply read an activity off the vial label and decide; it must either show the activity falls under a default table or perform a patient-specific dose calculation, and it must document the basis. For the broader licensing and program context this sits within, see our NRC radioactive material license guide and the radiation safety officer role that owns these procedures.

Topic Explanation

The Dose-Based Release Criterion

The operative sentence of 10 CFR 35.75(a) is short: the licensee may authorize the release of a patient who has been administered unsealed byproduct material or a permanent implant if the TEDE to any other individual is not likely to exceed 5 mSv (0.5 rem).¹ Three words in that sentence do the work:

"Any other individual" means the maximally exposed member of the public who is reasonably likely to be near the patient — typically a spouse, partner, parent, or primary caregiver who shares living space. It is not the general public passing on the street; it is the person who will spend the most time closest to the patient after release.²
"Not likely to exceed" signals a prospective, reasonable-assumption judgment rather than a measured certainty. The licensee uses conservative but realistic assumptions about distance, duration, and clearance.
"5 mSv (0.5 rem)" is a per-release limit on the dose to that other individual, distinct from the 1 mSv/yr public dose limit of 10 CFR Part 20 — the regulation explicitly carves out a higher allowance for the unavoidable, voluntary exposure of family members caring for a patient.^{1, 6}

The criterion is fundamentally different from an activity limit. A patient given a particular activity of I-131 who lives alone and can maintain distance from others may be releasable, while another patient given the same activity who is the sole caregiver for a small child may not be — the difference is entirely in the projected dose to the other individual, not in the patient.

The Written-Instruction and Breast-Feeding Triggers

A second threshold operates alongside the release limit. Under 10 CFR 35.75(b), when the dose to any other individual from the released patient could exceed 1 mSv (0.1 rem), the licensee must provide the patient — or the patient's parent or guardian — with written instructions on maintaining doses to others as low as reasonably achievable.¹ These instructions cover practical precautions: sleeping arrangements, distance and time with household members, hygiene, use of separate bathrooms and utensils, and the duration over which each precaution applies. Because most I-131 and Lu-177 therapy releases project doses above 1 mSv to at least one household member, written instructions are effectively standard for therapy.

A third, more specific trigger concerns breast-feeding. If the patient is breast-feeding an infant or child, the instructions must address interruption or discontinuation of breast-feeding and the potential consequences of failing to follow that guidance, because radioiodine and many other therapeutic radionuclides concentrate in breast milk and can deliver substantial dose — including thyroid dose — to a nursing infant.^{1, 2} For I-131 in particular, the guidance is to discontinue breast-feeding for the current child entirely. This breast-feeding instruction, where given, is itself a recordkeeping item under 10 CFR 35.2075.

Why "Released" Is Not "Unmonitored"

Release under 35.75 means the patient is no longer under the licensee's physical control — it does not mean the patient is no longer a radiation source. The released patient still carries radioactivity, may set off radiation-portal monitors at airports, borders, and some buildings for days to weeks, and may need a wallet card documenting the administration. A good release program anticipates these realities in its written instructions. The downstream side of the same isotopes — shielding and waste — is covered in our companion guides on radiopharmaceutical therapy shielding for Lu-177, Ra-223, and Ac-225 and radioactive waste management in nuclear medicine.

Key Technical Principles

Demonstrating that the dose to another individual is "not likely to exceed 5 mSv" rests on a small set of physics relationships: external dose rate from the patient treated as a point source, the decline of that dose rate over time governed by the effective half-life, and integration of the dose rate over time weighted by an occupancy factor that accounts for how much of that time the other individual is actually near the patient.

External Dose Rate From a Point Source

At distances large compared with the patient's body, the patient is approximated as a point source, and the external dose rate falls off as the inverse square of distance:

\dot{D} (r) = \frac{Γ A}{r ^{2}}

where $\dot{D} (r)$ is the dose-equivalent rate at distance $r$ , $A$ is the activity in the patient, and $Γ$ is the specific dose-rate constant (sometimes the exposure-rate or air-kerma-rate constant) for the radionuclide — the dose rate per unit activity at unit distance, with units such as mSv·m²·(GBq·h)⁻¹ or mR·h⁻¹·mCi⁻¹ at 1 cm depending on the system used. In the patient-release context, $Γ$ is most usefully expressed so that $\dot{D}$ comes out in mSv/h at $r = 1$ m for the activity in the patient.

The inverse-square term is the single most powerful precaution available to a released patient: doubling the distance to a household member cuts the dose rate to one-quarter. That is why "maintain distance" and "sleep apart" dominate the written instructions.

Effective Half-Life

The activity in the patient does not decline by physical decay alone — biological clearance (urinary, fecal, and other routes) removes activity as well. The two processes combine into the effective half-life:

T_{e f f} = \frac{T _{p} T _{b}}{T _{p} + T _{b}}

where $T_{p}$ is the physical half-life and $T_{b}$ is the biological half-life. Equivalently, the effective decay constant is the sum of the physical and biological constants, $λ_{e f f} = λ_{p} + λ_{b}$ . Because $T_{e f f}$ is always shorter than $T_{p}$ , using a patient-specific (or literature) effective half-life lowers the integrated dose relative to the conservative assumption that the patient clears nothing and decays only physically. For I-131, the physical half-life is 8.02 days, while typical post-therapy effective half-lives are considerably shorter and depend strongly on whether residual thyroid or thyroid-cancer tissue is present.^{2, 7}

Total Dose to the Maximally-Exposed Individual

If the dose rate at 1 m decays with effective half-life $T_{e f f}$ , the total integrated dose to a person who remained at 1 m continuously, starting at the time of release, is the time-integral of an exponentially decaying dose rate. Integrating $\dot{D} (t) = \dot{D}_{0} e^{- λ_{e f f} t}$ from release to infinity gives $\dot{D}_{0} / λ_{e f f} = \dot{D}_{0} T_{e f f} / ln 2$ . The NRC's model adds two real-world factors: an occupancy factor $E$ (the fraction of time the other individual is actually at the assumed distance) and unit handling so the dose rate, expressed per hour, integrates over the effective half-life expressed in days. The result is the standard NUREG-1556 / Regulatory Guide 8.39 form:^{2, 3}

D (\infty) = \frac{34.6 Γ Q _{0} T _{e f f}}{r ^{2}} (with occupancy E applied)

The constant 34.6 is not arbitrary: it is the product of 24 h/day and the factor 1.44 (which is $1/ ln 2$ , the mean life-to-half-life ratio), i.e. $34.6 = 24 \times 1.44$ . It converts a dose rate per hour and a half-life in days into a total integrated dose, assuming continuous (100% occupancy) exposure.² When the dose rate is measured directly at 1 m, the equation simplifies to a form built on the measured dose rate at 1 m rather than $Γ Q_{0} / r^{2}$ :

D (\infty) = 34.6 \times \dot{D} (1 m) \times T_{e f f} \times E

with $\dot{D} (1 m)$ in mSv/h, $T_{e f f}$ in days, and $E$ the dimensionless occupancy factor. Regulatory Guide 8.39 provides default occupancy factors — commonly an effective $E$ on the order of 0.25 for the period after release, reflecting that the other individual is not at 1 m around the clock — together with conventions for a two-phase (clearance-then-residual) decay for I-131.²

The Three Methods of Demonstrating Compliance

Regulatory Guide 8.39 and NUREG-1556 Volume 9 lay out three accepted ways to show the 5 mSv criterion is met, in increasing order of refinement and of the activity they can justify releasing:^{2, 3}

Default activity / dose-rate tables. Release is automatically justified if the administered activity is at or below the radionuclide's tabulated activity value, or if the measured dose rate at 1 m is at or below the tabulated dose-rate value. These tables are derived using conservative default assumptions (physical half-life, fixed occupancy) so that any patient under the value is releasable without further calculation. This covers the large majority of Lu-177, Ra-223, and lower-activity I-131 administrations.
Patient-specific calculation using the measured dose rate at 1 m. The licensee measures $\dot{D} (1 m)$ for the individual patient and computes $D (\infty)$ using the physical half-life and default occupancy. Because a measured dose rate is often lower than the conservative table assumption (geometry, patient size, early clearance already reflected in the measurement), this can justify releasing patients above the default-table activity.
Patient-specific calculation using measured effective half-life and occupancy. The most refined method additionally substitutes a patient-specific (or literature-supported) effective half-life and a justified occupancy factor, producing the lowest, most realistic projected dose. This is the method that releases higher-activity I-131 thyroid-cancer patients who clear quickly and live in low-occupancy situations.

Methods 2 and 3 require the licensee to keep records of the basis (10 CFR 35.2075). The deeper dosimetry that underpins individualized Lu-177 therapy — and increasingly informs release decisions — is covered in our guide to Lu-177 theranostics dosimetry.

Worked Example — Is an I-131 Patient Releasable by the Default Table?

Consider a thyroid-cancer patient administered 1.11 GBq (30 mCi) of I-131 sodium iodide. Historically this is the classic boundary case, because 30 mCi was the old fixed activity threshold and remains close to the I-131 default-table activity value for release.²

By the default-table method (Method 1), the licensee compares the administered activity to the tabulated I-131 release activity. The Regulatory Guide 8.39 default table lists an activity at or below which release is automatically justified; a 30 mCi (1.11 GBq) administration sits at or just under that default value for I-131, so this patient is generally releasable by the table without further calculation.

Now suppose the same patient is instead administered 3.7 GBq (100 mCi) for thyroid-cancer ablation. This clearly exceeds the I-131 default-table activity, so Method 1 alone does not justify release. The licensee must move to Method 2 or 3:

Measure the dose rate at 1 m after administration — say $\dot{D} (1 m) = 0.20$ mSv/h (an illustrative post-ablation value).
Apply the occupancy-weighted integral with an I-131 effective half-life. Using a single conservative $T_{e f f}$ and an occupancy factor $E = 0.25$ :

D (\infty) = 34.6 \times 0.20 \frac{mSv}{h} \times T_{e f f} (d) \times 0.25

With an illustrative effective half-life of $T_{e f f} = 0.32$ d for the early clearance phase, $D (\infty) \approx 34.6 \times 0.20 \times 0.32 \times 0.25 \approx 0.55$ mSv from the fast phase, to which the residual (thyroid-bound) component must be added before comparing to the 5 mSv limit.

The point of the worked example is the method, not the arithmetic: a 30 mCi patient clears the default table, a 100 mCi patient does not and requires a documented patient-specific calculation, and the released patient in the second case will certainly need written instructions because the projected dose to a household member exceeds 1 mSv. Every patient-specific number that drives the release decision must be measured or justified and then recorded.

Clinical Impact

Patient release sits at the intersection of regulatory compliance, treatment access, and the safety of the people the patient goes home to. Getting it right shapes both the patient's experience and the program's risk.

It expands outpatient therapy. The dose-based standard is what allows many I-131, Lu-177, and Ra-223 treatments to be delivered without inpatient radiation-isolation admission, lowering cost and freeing capacity — provided the release evaluation and instructions are done correctly.^{2, 5}
It protects household members and the public. The whole framework exists to keep the dose to a spouse, child, or caregiver within 5 mSv and to give families the practical knowledge to keep their own doses ALARA. The written instructions are not paperwork; they are the primary engineering control once the patient leaves.¹
It protects the most vulnerable contacts. The breast-feeding and pregnancy considerations exist because a nursing infant or a fetus can receive far higher organ doses — especially thyroid dose from radioiodine — than an adult contact. A missed breast-feeding instruction is among the most serious failures a release program can have.^{2, 8}
It is increasingly individualized. As therapeutic nuclear medicine moves toward higher activities and theranostic, dosimetry-guided regimens (Lu-177 DOTATATE, Lu-177 PSMA), release decisions lean more on patient-specific measurement than on default tables, raising the bar for the physics support behind them.^{7, 9}

By therapy: I-131 (thyroid cancer, hyperthyroidism) is where release calculations are most often non-trivial, because activities span from ~30 mCi outpatient hyperthyroid treatments to multi-GBq ablations. Lu-177 DOTATATE and Lu-177 PSMA are typically releasable by the default-table method given Lu-177's lower-energy emissions and the activities used, but still require instructions and records. Ra-223 dichloride, an alpha emitter with minimal external dose rate, is essentially always releasable, with instructions focused on fecal/urinary precautions rather than external distance. I-131 mIBG for neuroblastoma and certain neuroendocrine tumors, at high activities and often in pediatric patients, is the most demanding release scenario and frequently does require isolation and careful caregiver dosimetry.

Practical Optimization Tips

A defensible release program turns the regulation into a repeatable, documented workflow:

Pre-plan the release before administration. Decide which method applies based on the planned activity and the patient's living situation before dosing, so the right measurements (dose rate at 1 m) are scheduled and the instructions are ready.
Measure the dose rate at 1 m with a calibrated, appropriate instrument. A measured $\dot{D} (1 m)$ is the foundation of Methods 2 and 3; use a survey meter with a current calibration and a documented geometry, and record the time post-administration at which it was taken.
Use defensible effective half-lives. Prefer a patient-specific $T_{e f f}$ when you can measure serial dose rates; otherwise cite the literature/Reg Guide value and state the assumption. Never silently substitute physical half-life when you have claimed an effective-half-life method.
Write occupancy assumptions down. The occupancy factor and any distance assumptions are the most scrutinized inputs in an inspection. State the value, cite the source (Reg Guide 8.39 default or a documented patient-specific rationale), and keep it conservative.
Standardize the written instructions. Maintain template instruction sheets per radionuclide that cover distance, time, sleeping arrangements, hygiene, duration of precautions, and breast-feeding — and document that the patient received and understood them.
Screen every patient for pregnancy and breast-feeding. Make this a hard gate in the workflow, with the breast-feeding instruction and its recordkeeping triggered automatically. Pair this with sound occupational exposure monitoring so that staff dose around these higher-activity patients is also controlled.
Keep the records before you need them. For any patient-specific release, file the measurements, the effective half-life, the occupancy factor, the calculation, and the instruction acknowledgment together, so the 10 CFR 35.2075 record is complete and retrievable for the full retention period.

Regulatory Considerations

Patient release is a tightly regulated activity, and the citations an inspector will use are specific:

10 CFR 35.75(a) — Release criterion. A patient may be released if the TEDE to any other individual is not likely to exceed 5 mSv (0.5 rem). This is the controlling limit.¹
10 CFR 35.75(b) — Written instructions. Required when the dose to any other individual could exceed 1 mSv (0.1 rem), and must address breast-feeding interruption/discontinuation and its consequences where applicable.¹
10 CFR 35.2075 — Records of release. The licensee keeps a record of the basis for release when patient-specific factors were used, and a record of breast-feeding instructions given when the projected dose to a nursing child could exceed the defined thresholds; records are retained for three years.⁴
Regulatory Guide 8.39 / NUREG-1556 Vol. 9 — Methods. These provide the default activity and dose-rate tables, the patient-specific calculation methods, default occupancy factors, and the model instruction content the NRC expects to see implemented.^{2, 3}
10 CFR Part 20 — Public and dose framework. The general 1 mSv/yr public dose limit and the ALARA philosophy sit behind 35.75; the 5 mSv release allowance is a deliberate, bounded exception for family/caregiver exposure.⁶
ICRP Publication 94 and NCRP Report No. 155 — Consensus guidance. These provide the international and national scientific basis for release of patients after unsealed-radionuclide therapy and the management of therapy patients, and are useful authorities when defending a patient-specific approach.^{8, 10}

Jurisdiction follows the materials-program rule. The NRC directly regulates non-Agreement States and Washington DC, while Florida, Maryland, Virginia, California, and Nevada are Agreement States whose regulations must be compatible with 10 CFR 35.75 — so the 5 mSv release limit and 1 mSv instruction trigger apply uniformly across all six DRPS service areas, even though the exact section number and any supplemental state guidance should be confirmed against the applicable state code.^{2, 3} These release procedures must be written into the radiation protection program, and they intersect directly with the authorized-user and RSO duties described in our radiation safety officer role guide.

Frequently Asked Questions (FAQs)

What is the patient release limit under 10 CFR 35.75?

A licensee may release a patient who has received unsealed byproduct material or a permanent implant if the total effective dose equivalent (TEDE) to any other individual from exposure to the released patient is not likely to exceed 5 mSv (0.5 rem). The limit is a dose to other people, not a residual-activity cutoff, so the same administered activity can be releasable for one patient and not another depending on their living situation.

How do you demonstrate compliance with the 5 mSv release criterion?

Regulatory Guide 8.39 and NUREG-1556 Volume 9 describe three accepted methods: (1) the default activity and dose-rate tables, which release a patient if the administered activity or measured dose rate at 1 m is at or below the listed value; (2) a patient-specific calculation using the measured dose rate at 1 m with the physical half-life and conservative default assumptions; and (3) a patient-specific calculation that also uses the patient's measured effective half-life and a realistic occupancy factor. Methods 2 and 3 let you justify releasing patients above the default table values.

When must a patient receive written radiation safety instructions?

Under 10 CFR 35.75(b), the licensee must give the released patient (or the patient's parent or guardian) written instructions on how to keep doses to other individuals as low as reasonably achievable whenever the dose to any other individual is likely to exceed 1 mSv (0.1 rem). In practice most therapy programs provide written instructions for essentially all I-131 and Lu-177 therapy releases. If the patient is breast-feeding, the instructions must also address interruption or discontinuation of breast-feeding and the consequences of failing to follow that guidance.

What records are required after releasing a therapy patient?

Under 10 CFR 35.2075, when the dose was calculated using patient-specific factors the licensee must keep a record of the basis for authorizing release, including the measurements, the effective half-life and occupancy factor used, and the calculation. When breast-feeding instructions were given because the projected dose to a nursing infant or child could exceed defined thresholds, that record must be kept as well. These records are retained for three years.

What is the effective half-life and why does it matter for patient release?

The effective half-life combines the physical half-life of the radionuclide with the biological half-life describing how quickly the body clears it. Because biological clearance shortens the time the patient is a source, using the effective half-life rather than the physical half-life lowers the calculated dose to others. For radionuclides with significant clearance such as I-131 in many patients, a patient-specific effective half-life can make a patient releasable when the conservative physical-half-life calculation would not.

Does patient release apply the same way in Florida, Maryland, and other Agreement States?

The dose-based release framework is essentially uniform nationwide. The NRC directly regulates Washington DC and non-Agreement States, while Florida, Maryland, Virginia, California, and Nevada are Agreement States whose regulations must be compatible with 10 CFR 35.75. The 5 mSv release limit and the 1 mSv written-instruction trigger therefore apply in all of these jurisdictions, though the exact citation number and any state-specific guidance should be confirmed against the applicable state code.

Which therapies most commonly require a patient release evaluation?

The most frequent are I-131 sodium iodide for thyroid cancer and hyperthyroidism, where higher activities can exceed default release values; Lu-177 DOTATATE for neuroendocrine tumors and Lu-177 PSMA for prostate cancer; Ra-223 dichloride for bone metastases; and I-131 mIBG. Ra-223 and most Lu-177 administrations are typically releasable by the default-table method, while higher-activity I-131 thyroid-cancer treatments are where patient-specific calculations are most often needed.

Key Takeaways

The release limit is dose-based, not activity-based. Under 10 CFR 35.75, a patient is releasable if the TEDE to any other individual is unlikely to exceed 5 mSv (0.5 rem) — so living situation, not just administered activity, decides releasability.¹
There are three accepted compliance methods. Default activity/dose-rate tables, a patient-specific calculation from the measured dose rate at 1 m, and a patient-specific calculation using the measured effective half-life and occupancy factor — each more refined and able to justify higher releases than the last.^{2, 3}
The physics is inverse-square decay integrated over time. $\dot{D} (r) = Γ A / r^{2}$ , an effective half-life $T_{e f f} = T_{p} T_{b} / (T_{p} + T_{b})$ , and the NUREG-1556 dose integral whose 34.6 constant is just $24 \times 1.44$ (hours/day times $1/ ln 2$ ).²
Written instructions are triggered at 1 mSv, must address breast-feeding where relevant, and are effectively standard for I-131 and Lu-177 therapy releases.¹
Records are mandatory for patient-specific releases under 10 CFR 35.2075 — the basis, measurements, half-life, occupancy, and calculation — and are kept for three years.⁴
The framework applies uniformly across DRPS's six service areas. Florida, Maryland, Virginia, California, and Nevada are Agreement States with compatible rules; Washington DC is regulated directly by the NRC.²

Conclusion

Patient release after radiopharmaceutical therapy is deceptively simple in statement — release if the dose to any other individual is unlikely to exceed 5 mSv — and demanding in execution. The dose-based standard of 10 CFR 35.75 rewards programs that measure, calculate, and document: it lets a quickly-clearing, low-occupancy patient go home on a higher activity, while requiring real justification to do so. The equations are well established — inverse-square dose rate, the effective half-life, and the occupancy-weighted dose integral with its 34.6 constant — but the defensibility of any individual release rests on the inputs: a calibrated dose-rate measurement, a justified effective half-life, a conservative occupancy factor, complete written instructions (including breast-feeding), and a 10 CFR 35.2075 record that ties them together. As therapeutic nuclear medicine grows and individualizes, the physics support behind the release decision is exactly what keeps outpatient therapy both accessible and safe for the families patients return to.

How DRPS Can Help

Patient release demands calibrated measurement, correct dose calculation, defensible recordkeeping, and procedures that survive an inspection — work that maps directly to medical physics and RSO support. Diagnostic Radiation Physics Services (DRPS) supports nuclear medicine and theranostics programs across Florida, Maryland, Virginia, Washington DC, California, and Nevada with:

Patient-release procedure development — written 10 CFR 35.75 methodology, default-table and patient-specific calculation templates, default and patient-specific occupancy and effective-half-life conventions, and audit-ready documentation.
Release dose calculations and dose-rate measurement protocols — calibrated survey-meter measurement procedures at 1 m and the supporting math for higher-activity I-131, Lu-177, Ra-223, and I-131 mIBG releases.
Written-instruction and breast-feeding templates per radionuclide, with the recordkeeping that 10 CFR 35.2075 requires.
RSO and program support — integrating release into the radiation protection program, license amendments, and mock inspections.

Learn more about our Radiation Safety Officer services, radioactive material license support, and medical physicist consulting, or see the states we serve on our locations page.

Related Resources

References

U.S. Nuclear Regulatory Commission. 10 CFR 35.75, Release of individuals containing unsealed byproduct material or implants containing byproduct material. ecfr.gov
U.S. Nuclear Regulatory Commission. Regulatory Guide 8.39, Revision 1: Release of Patients Administered Radioactive Material. nrc.gov
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
U.S. Nuclear Regulatory Commission. 10 CFR 35.2075, Records of the release of individuals containing unsealed byproduct material or implants containing byproduct material. ecfr.gov
U.S. Nuclear Regulatory Commission. Final Rule: Criteria for the Release of Individuals Administered Radioactive Material, 62 Fed. Reg. 4120 (Jan. 29, 1997). nrc.gov
U.S. Nuclear Regulatory Commission. 10 CFR Part 20, Standards for Protection Against Radiation. ecfr.gov
Cherry SR, Sorenson JA, Phelps ME. Physics in Nuclear Medicine. 4th ed. Elsevier/Saunders; 2012.
International Commission on Radiological Protection. Release of Patients After Therapy with Unsealed Radionuclides. ICRP Publication 94. Ann ICRP 34(2); 2004. icrp.org
Society of Nuclear Medicine and Molecular Imaging. Procedure Standards and guidance for radionuclide therapy and patient release. SNMMI. snmmi.org
National Council on Radiation Protection and Measurements. Management of Radionuclide Therapy Patients. NCRP Report No. 155. NCRP; 2006. ncrponline.org