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{{#Wiki_filter:Public Meeting on Information Request Draft Regulatory Guide 8061, Release of Patients Administered Radioactive Material.
{{#Wiki_filter:ec Q Blr Q Blins}}
July 20, 2023
 
Welcome and Logistics
 
===Background===
Overview of Proposed Changes (Patient Perspective)
How to Prepare and Submit Comments Question and Answer Session Overview of the Modifying Factors and Examples of Calculations Question and Answer Session
 
Logistics
* Meeting is being transcribed
* Keep the line muted until you intend to speak
* Raise hand button in Teams (*5 on phone)
* Unmute button in Teams (*6 on phone)
* Chat feature available
* Presentation slides shown on the Microsoft Teams screen and in ADAMS at ML23198A203
* Phone attendees should email Brian.Allen3@nrc.gov for attendance 3
 
Purpose
* Provide an overview of the proposed changes to the NRC Regulatory Draft Guide (DG)-8061, Release of Patients Administered Radioactive Material,  to help the public prepare comments on the guide
* Share the different methods by which you may submit comments on the DG
* The NRC is not seeking comments at this meeting.
* Comments should be submitted according to the instructions in the FRN (88 FR 38407) by August 20, 2023.
4
 
Opening Remarks Kevin Williams Division Director Division of Materials Safety, Security, State, and Tribal Programs
 
===Background===
Katie Tapp, PhD Medical Physicist Medical Radiation Safety Team
 
NRC Policy on Medical Use of Radioactive Materials
* The Nuclear Regulatory Commission (NRC) will regulate the uses of radioactive material in medicine as necessary to provide the radiation safety of workers and the general public.
* The NRC will not intrude into medical judgements affecting patients, except as necessary to provide for the radiation safety of workers and the general public.
 
Patient Release Regulations (10 CFR 35.75)
* 10 CFR 35.75 allows the licensee to release from its control any patient who has been administered radioactive material if the total radiation dose to any other individual from exposure to the released patient is not likely to exceed 5 mSv (500 mrem).
* Licensees must provide written instructions to the patient to maintain doses ALARA if the exposure to any other individual is likely to exceed 1 mSv (100 mrem).
* Licensee must also provide specific instructions if the total effective dose equivalent to a nursing infant or child could exceed 1 mSv (100 mrem), assuming there was no interruption of breastfeeding.
 
Patient Release Regulations (10 CFR 35.75)
* The limits are for each patient treatment.
* The NRC regulations apply to the licensee, and not the patients.
* Regulatory Guide 8.39 provides guidance on how licensees can demonstrate they meet this requirement.
 
Evaluation of Regulatory Requirements for Patient Release
* In January 2018, the NRC completed an evaluation of its patient release program.
* Results were published in SECY-18-0015, Staff Evaluation of the U.S. Nuclear Regulatory Commission's Program Regulating Patient Release After Radioisotope Therapy
* Findings -
* The regulations are adequate to protect the public
* Guidance update is needed as methodology in the guidance can UNDERESTIMATE potential dose to a member of the public in some situations.
 
RG 8.39, Release of patients administered radioactive material, Revision 1
* Current version of patient release guidance
* Issued in April 2020 to include recommendations for:
* Pretreatment discussions
* Patient instructions to maintain doses ALARA
* Additional instructions provided to the NRC during public comments by the industry
* Patient acknowledgement of instructions
* The current draft did not include significant updates to these sections
 
General Overview of Proposed Changes Katie Tapp, PhD Medical Physicist Medical Radiation Safety Team
 
DG 8061, Release of patients administered radioactive material
* Proposed Draft Regulatory Guidance (DG) to update Regulatory Guide (RG) 8.39
* Proposed changes include
* Updated dosimetry methodology
* Updated breastfeeding cessation guidelines
* The NRC is requesting public comments until August 20, 2023 (88 FR 38407)
 
Baseline and patient specific release Two-tiered approach to release - baseline thresholds and patient specific release values Administered activity and measured dose rate baseline thresholds that licensees can use to release patients without gathering patient specific information.
The proposed revision provides updated guidance on how patient specific information can be used to demonstrate release would comply with regulations.
 
Exposure Pathways
* The equations provided in the DG consider external exposure and do not include internal exposure due to uptake by the individual other than the patient.
* Previous studies and NRC evaluation found potential intake by household members and other members of the public is negligible (less than a few percent) relative to external doses, when instructions are followed.
* Instructions and precaution recommendation were not updated in this DG as they were recently updated in the last revision.
 
Baseline Thresholds
* Added new radionuclides to the table, such as Lu-177.
* Used CONSERVATIVE assumptions to ensure all released patients are not likely to cause exposure to other individuals in excess of 5 mSv (500 mrem).
* Due to these CONSERVATIVE assumptions, licensees do not need patient specific information to release patients who have administered activity (or have measured dose rates) below values found in the tables.
 
Patient Specific Release
* If a patient has administered activity (or measured dose rate) above baseline thresholds, patient specific information is needed to determine if release can be authorized.
* Patient specific information is used to add realism to the conservative assumptions used to develop the baseline threshold values.
 
Patient Specific Release
* The proposed draft guidance recommends use of 4 modifying factors to change the baseline thresholds based on patient release information.
* Occupancy (FO)
* Geometry (FG)
* Attenuation (FA)
* Biokinetics (FB)
* Licensees can choose to use patient specific information for some factors while keeping conservative values for others
 
Occupancy Factor
* Occupancy factor is the amount of time an individual is near the patient while the radioactive material decays.
* The less time the individual is near the patient while the material decays, the less exposure they will receive.
* The baseline threshold assumes an individual is 1 meter away from a patient all the time.
* To determine a patient specific occupancy factor, patient specific information is necessary.
 
Geometry Factor
* The baseline threshold assumes:
o A conservative geometry where the source and individual exposed are points o That the patient and individual are always 1 meter away
* The geometry factor allows licensees to modify the likely exposure scenarios based on:
o Conversations with the patient to determine likely distance and geometry of exposure scenarios, and o Medical knowledge of where the radionuclide will travel inside the patient
 
Attenuation Factors
* Baseline threshold assumes no attenuation (shielding) or buildup between source and individual.
* Patient specific attenuation factor is dependent on the expected depth of the source in the body.
* Attenuation factors can be greater than 1.
* Licensees should use the most conservative attenuation factor for the radionuclide if they do not plan to determine patient specific attenuation factors as conservatism is being removed from other factors.
* The DG provides the most conservative values and graphs for licensees to select attenuation values if thickness is known.
 
Biokinetic Factors
* The baseline threshold conservatively assumes no biological removal of the radionuclide.
* Licensees can continue to use this conservative assumption when patients retention data is unknown.
* The DG provides guidance on how licensees can adjust for patient specific excretion (i.e., removal) for additional realism.
 
How to Prepare and Submit Comments
 
Tips for Preparing Comments
* Review the Commenters Checklist on Regulations.gov 25
 
Methods for Submitting Comments
* Regulations.gov: comment form Docket ID NRC-2023-0086 or
* Email: Rulemaking.Comments@nrc.gov or
* Mail: Secretary, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001 ATTN: Rulemakings and Adjudications Staff 26
 
Next Steps
* Public comment period ends: August 20, 2023
* NRC staff updates draft regulatory guide based on public comments and feedback prior to publishing final regulatory guide 8.39, Release of Patients Administered Radioactive Material.
27
 
Public Feedback and Questions WE ARE ON BREAK.
We will return at 1:30pm ET for the second part of the meeting.
 
PROPOSED PHASE 2 UPDATES TO REGULATORY GUIDE 8.39 ON PATIENT RELEASE: DOSIMETRY METHODOLOGY JULY 20, 2023
 
OVERVIEW Phase 2 revisions to Regulatory Guide 8.39 are intended to update the dosimetry methodology Proposed direction provides versatile, realistically-conservative dosimetry Basic activity thresholds with the ability, if necessary, to generate patient-specific values Thresholds are based on maximum dose equivalent limits found in 10 CFR 35.75 Through patient instruction & interruption, breastfeeding infants are protected to 1 mSv Emerging technologies are easily supported with the new methodology RCD RADIATION PROTECTION ASSOCIATES                                                            31
 
WHATS DIFFERENT GIVEN PHASE 2 REVISIONS?
If the administered activity (A0) is less than the basic activity threshold appearing in Table 1:
o there is no change for the licensee If, however, A0 is greater than the activity threshold listed in Table 1, the license should select one of the following options for patient release:
o release the patient based on measured dose rates (Table 2);
o release the patient based on retained activity instead of administered activity; o calculate patient-specific activity thresholds to determine patient release; or o calculate a hold time prior to patient release.
For a breastfeeding patient o if A0 is less than the revised breastfeeding threshold (Table 3), there is no change for the licensee o if, however, A0 is greater than the breastfeeding threshold, the licensee should calculate a breastfeeding interruption time and advise the patient accordingly RCD RADIATION PROTECTION ASSOCIATES                                                                          32
 
COLUMN 1                            COLUMN 2 RADIONUCLIDE      Patient Release Threshold            Instruction Threshold I-124            0.20                5.4 TABLE 1                                                        I-125 I-125 implanta 0.074 0.084 Ag-111 At-211 Au-198 2.0 2.3 (GBq) 4.4 17 0.88 (mCi) 120 460 24 (GBq) 0.88 3.3 0.18 (mCi) 24 89 4.9 Bi-213          210              5,700              41              1,100 COLUMN 1                      I-131 COLUMN 2                0.32          C-11  8.6      68              1,800              14                380 C-14b        0.0014              0.038          0.00028            0.0076 ACTIVITY AT OR BELOW                    In-111 DOSE RATE AT 1 METER, AT OR      0.64          Cr-51  17      1.1                30              0.23              6.2 WHICH PATIENTS MAY BE    BELOW WHICH    Ir-192 PATIENTS MAY 0.015          Cs-1310.41 Cs-131 implanta 1.1 1.1 30 30 0.21 0.23 5.7 6.2 RELEASED              BEIr-192  implantba RELEASED            0.016          Cu-640.43      9.7                260              1.9                51 Cu-67          3.7                100              0.75                20 RADIONUCLIDE                (GBq)            (mCi)  (mSv/h)      Lu-177  (mrem/h)    4.1        Dy-165 110      320              8,600              65              1,800 Ag-111                        19              520      0.08        N-13        8    140              3800 Er-169b        130              3,500              26                700 F-18          13                350              2.5                68 Au-198                        3.5            93      0.21        O-15        21    680              18,000 Ga-67          2.1                57 Several radionuclides 0.42                11 Ga-68          22                590              4.4                120 Cr-51                          4.8            130      0.02        P-32b        2    9.2        Ho-166b 250      26                700        have been added 5.2                140 Cu-64                          8.4            230      0.27        P-33b      27      64          I-1231,700    6.7                180              1.3 (from 22 to 52)        35 I-124          0.20                5.4            0.041              1.1 Cu-67                        14              390      0.22      Pd-103      22    0.27        I-125  7.3    0.074                2.0            0.015              0.41 Ga-67                          8.7            240      0.18 Pd-103 implanta18                I-125 implanta    0.084                2.3    Threshold decreases from 0.017              0.46 0.39        I-131  11      0.32                8.6            0.063              1.7 I-123                          6.0            160      0.26      Ra-223      26    0.27        In-111  7.3    0.64                17        1.2 GBq to 0.32 GBq (a 0.13              3.5 Ir-192        0.015              0.41          0.0030            0.081 I-125                          0.25            7      0.01      Rb-82        1    960              26,000 Ir-192 implanta    0.016              0.43      factor of 4) because the 0.0033              0.089 I-125 implant                  0.33            9      0.01      Re-186        1    6.2        Lu-177 170      4.1              110              0.82 assumption of 25% occupancy    22 N-13          140                3800              28                760 I-131                          1.2            33      0.07      Re-188b        7      16          O-15 430      680              18,000            140              3,800 In-111                        2.4            64      0.2                                        P-32b                                    for nuclides with T > 1 day Ru-106b 20 9.2                250              1.8                49 r 180          P-33b4,900      64              1,700              13                350 Ir-192 implant                0.074            2      0.008Ru-106b implanta 0.8      200        Pd-103 5,400    0.27                7.3          has been removed 0.055                1.5 Pd-103 implanta      0.39                11            0.077              2.1 P-32c                          c              c        c        Sc-47      c      3.1        Ra-223  84      0.27                7.3            0.054              1.5 Pd-103 implant                1.5            40      0.03        Se-75        3  0.0080 Rb-82 0.22 960              26,000            190              5,100 At this stage of the methodology, Re-186          6.2                170              1.2                32 Re-186                        28              770      0.15      Sm-153 15            6.8        Re-188b Ru-106b 180      16 180 430 4,900 3.1 100% occupancy is assumed 37 84 1,000 Re-188                        29              790      0.20      Sn-117m 20          0.29                7.8 Ru-106b implanta      200              5,400            550              15,000 Sc-47                        11              310      0.17                    17                  Sc-47          3.1                84          for all radionuclides 0.62                17 Sr-89b              3.3          Se-75  89    0.0080              0.22          0.0016              0.043 Se-75                          0.089            2      0.005                    0.5 Sr-90b            0.055      Sm-153 1.5    6.8                180              1.4                38 Sm-153                        26              700      0.3                    30                Sn-117m          0.29                7.8          Pure beta emitters 0.058              1.6 Tc-99m                30        Sr-89b  810    3.3                89              0.66                18 Sn-117m                        1.1            29      0.04                    4                Sr-90b        0.055                1.5          have been added 0.011              0.30 Tl-201              1.2        Tc-99m    32      30                810            6.1                160 Sr-89c                        c              c        c                    c                                                                    (bremsstrahlung) 28              760 Xe-127            0.073        Tl-201 2.0    1.2                32            0.23                6.2 Tc-99m                                                0.58                    58                Xe-127        0.073                2.0            0.015              0.41 Tl-201                        16              430      0.19      Xe-133      19    2.1        Xe-133  57    2.1                  57            0.42                11 b                          Y-90b          34                920            6.8                180 Yb-169                        0.37            10      0.02      Y-90          2      34        Yb-169  920    0.094                2.5            0.019              0.51 Yb-169            0.094        Zr-89 2.5    0.21                5.7            0.042              1.1 Zr-89            0.21                5.7 RCD RADIATION PROTECTION ASSOCIATES                                                                                                                                        33
 
THRESHOLD FRAMEWORK Table 1 Column 2          Table 1 Column 1 Basic Threshold            Basic Threshold for Instruction        for Patient Release Dose to Bystander                            No Regulatory                Provide          Alternative Methods Action                    ALARA          To Determine Release Instructions 1 mSv to                  5 mSv to Bystander                Bystander Release Authorized                                  No Release RCD RADIATION PROTECTION ASSOCIATES                                                                    34
 
EXAMPLE 1: BASELINE RELEASE 56-year-old male administered 1.3 GBq of 90Y microspheres for the treatment of hepatocellular carcinoma Because this is a pure beta emitter, the current release/instruction thresholds are non-existent From proposed Table 1, the basic activity thresholds are 34 GBq (for release) and 6.8 GBq (for instructions)
Because 1.3 GBq is below both thresholds, the licensee is authorized to release the patient without dose-minimizing instructions 1.3 GBq              6.8 GBq                      34 GBq Basic Threshold              Basic Threshold for Instruction                for Release Dose to                                                                        Alternative Method Bystander            No Regulatory Action                  ALARA Instructions 1 mSv to                      5 mSv to Bystander                    Bystander RCD RADIATION PROTECTION ASSOCIATES Release Authorized                              No Release    35
 
CALCULATING THE PATIENT-SPECIFIC THRESHOLDS In the proposed method, if a patient cannot be released based on the basic activity thresholds (Q) found in Table 1, the licensee may want to determine patient-specific activity thresholds (Q)
To carry out this calculation, modifying factors for biokinetics (FB), occupancy (FO),
geometry (FG), and attenuation (FA) are determined The patient-specific threshold is calculated using:
                                      =
RCD RADIATION PROTECTION ASSOCIATES                                                      36
 
EXAMPLE 2: PATIENT-SPECIFIC RELEASE 75-year-old male administered 7.4 GBq of 177Lu vipipotide tetraxetan for the treatment of metastatic castration-resistant prostate cancer From proposed Table 1, the basic activity thresholds are 4.1 GBq (for release) and 0.82 GBq (for instructions) 7.4 GBq is above both thresholds, therefore the licensee decides to calculate patient-specific thresholds 0.82 GBq                  4.1 GBq              7.4 GBq Basic Threshold              Basic Threshold for Release for Instruction Dose to Bystander                                              ALARA                Alternative Method No Regulatory Action Instructions 1 mSv to                  5 mSv to Bystander                  Bystander Release Authorized                              No Release RCD RADIATION PROTECTION ASSOCIATES                                                                              37
 
EXAMPLE 2: OCCUPANCY FACTOR During the initial patient interview, the patient states:
his spouse will drive him home after administration; he is sitting in the back seat of a private vehicle as normal, he plans to sleep next to his spouse (king-size bed) he eats meals with his spouse, but the two are in close proximity for no more than 4 waking hours in a day no other individuals live in the house, but his daughter plans to stop by for dinner a few days after treatment he is retired and can stay home for the first few days after treatment he plans to get groceries and go to church on the weekends Thus, over the first few weeks (6.7-day half-life), the maximally exposed individual is likely the patients spouse Assuming 8 hours of sleep and 4 hours of contact, the CONSERVATIVE patient-specific occupancy factor is:
(8 + 4)
                                    =            = 0.5 24 RCD RADIATION PROTECTION ASSOCIATES                                                                                    38
 
EXAMPLE 2: GEOMETRY FACTOR The patients spouse is likely the maximally exposed individual and it is assumed that exposures (on average) will occur at approximately 1 meter The licensee chooses to assume that the radiation source is a point, but that radiation dose absorbed by the spouse (bystander) is better represented assuming a line receptor From Table B-1 of the draft Regulatory Guide 8.39, this orientation results in a geometry modifying factor of:
                                                                                = 0.87 RCD RADIATION PROTECTION ASSOCIATES                                                                    39
 
EXAMPLE 2: BIOKINETIC AND ATTENUATION FACTORS In this initial determination, the licensee chooses to use the most conservative biokinetic and attenuation factors in place of patient specific values Most conservative biokinetic factor is always:        =1 Attenuation factors are radionuclide specific, and their maximum value can be found in Table A-1 of the draft regulatory guide This factor includes both attenuation and build up and, at times, can be greater than 1; the maximum value listed in Table A-1 for 177Lu is:
                                    = 1.25 RCD RADIATION PROTECTION ASSOCIATES                        40
 
EXAMPLE 2: PATIENT-SPECIFIC ACTIVITY THRESHOLDS For this patient, and depending on their stated plans, habits, etc., the release and instruction thresholds for an administration of Lu-177 are:
4.1
                                    =                    =                                = 7.5
                                      *      *
* 1
* 0.5
* 0.87
* 1.25 7.4 GBq 0.82
                                    =                      =                                = 1.5
                                      *      *
* 1
* 0.5
* 0.87
* 1.25 Recall, this patient received an administration of 7.4 GBq The patient can be released, but must be provided dose-minimizing instructions and those instructions must be consistent with stated plans, sleeping arrangement, etc. and ALARA considerations RCD RADIATION PROTECTION ASSOCIATES                                                                                              41
 
EXAMPLE 3: IODINE ADMINISTRATION 46-year-old female administered 1.8 GBq of 131I as sodium iodide Proposed basic activity thresholds (Table 1) for 131I are Qrel = 0.32 GBq (release) and      Qins =
0.063 GBq (instructions) recall, current release threshold is 1.2 GBq for 131I Because 1.8 GBq is greater than both thresholds, the licensee decides to calculate patient-specific thresholds The licensee chooses to determine a value for each modifying factor With patient-specific thresholds, is immediate release allowable?
Are instructions required?
RCD RADIATION PROTECTION ASSOCIATES                                                                    42
 
EXAMPLE 3: BIOKINETICS, FB Consistent with current guidance (Table B-1) and several citations in the literature, the licensee assumes a double-exponential retention model for elemental iodine Uptake fractions of 0.2 and 0.8 for the extrathyroidal and thyroid components are assumed, with effective half-lives of 7.7 hours and 125 hours, respectively I-131 has a radiological half-life of 192 hours The biokinetic modifying factor can be calculated as a weighted sum of effective half-lives in the two components divided by the radiological half-life:
0.2 7.7  + 0.8 125
                                      =                                  = 0.53 192 RCD RADIATION PROTECTION ASSOCIATES                                                                      43
 
EXAMPLE 3: OCCUPANCY, FO During the initial patient interview regarding the treatment plan, the patient states o    she will drive herself to/from her appointment; o    she will sleep with her husband, but will keep her distance otherwise; o    she is retired, but her husband is still working; o    and no other individuals live in their home.
Thus, the maximally exposed individual is very likely to be her husband Assuming 8 hours of sleep, the patient-specific occupancy factor is:
8
                                            =            = 0.33 24 RCD RADIATION PROTECTION ASSOCIATES                                                      44
 
EXAMPLE 3: GEOMETRY, FG The patient has been administered I-131 as sodium iodide Thus, the bulk of the radionuclide is expected to concentrate in the thyroid (a point source)
Basic thresholds assume point-to-point geometry at 1 meter, but for this patient-specific case, the licensee assumes a point source (thyroid) and a line receptor (torso of the maximum bystander)
Again, from Table B-1 of the draft Regulatory Guide, this orientation results in a geometry factor of:
                                                                                        = 0.87 RCD RADIATION PROTECTION ASSOCIATES                                                                      45
 
EXAMPLE 3: ATTENUATION, FA Because the radioactivity is likely concentrated in the thyroid, the licensee estimates 2 cm of overlying tissue in that area of the body The figure to the left is a plot of the attenuation modifying factor (FA) as a function of thickness of overlying tissue for I-131 FA accounts for both attenuation AND photon buildup (weve seen that FA can exceed 1.0)
At a thickness of 2 cm, this patient-specific attenuation factor is 1.0
                                    = 1.0 RCD RADIATION PROTECTION ASSOCIATES                                                          46
 
EXAMPLE 3: PATIENT-SPECIFIC ACTIVITY THRESHOLDS For this patient, and depending on their stated plans, habits, etc., the release and instruction thresholds for an administration of I-131 (as NaI) are:
0.32
                                    =                    =                          = 2.1
                                      *      *
* 0.53
* 0.33
* 0.87
* 1.0 1.8 GBq 0.063
                                    =                    =                          = 0.41
                                      *      *
* 0.53
* 0.33
* 0.87
* 1.0 This patient can be released, but must be provided dose-minimizing instructions consistent with stated plans, sleeping arrangement, etc.
RCD RADIATION PROTECTION ASSOCIATES                                                                    47
 
EXAMPLE 4: CALCULATION OF A HOLD TIME Lets use the previous example, but change the administered activity to 2.3 GBq With a Qrel of 2.1 GBq, the patient must be held, but for how long?
Retention data for this patient indicates that about 70% of a pretreatment I-131 administration remained in the patients body after 48 hours Then, using equation 11 (Section 2.3, Page 17), the hold time for this patient is:
48        2.1
                                    =            ln        = 12 ln(0.70)      2.3 RCD RADIATION PROTECTION ASSOCIATES                                                              48
 
EXAMPLE 5: WHAT IF THE PATIENT IS BREASTFEEDING?
26-year-old female is administered 0.04 GBq 89Zr panitumumab for imaging Proposed Table 1 indicates basic release and instruction thresholds of 0.26 GBq and 0.052 GBq for 89Zr The patient can be released without instruction HOWEVER, the patient tells you they are breastfeeding 0.04 GBq 0.052 GBq                        0.26 GBq Basic Threshold              Basic Threshold for Instruction                for Release Dose to Bystander No Regulatory Action                ALARA                  Calculate Patient-Instructions                  Specific 1 mSv to                      5 mSv to Thresholds Bystander                    Bystander Release Authorized                              No Release RCD RADIATION PROTECTION ASSOCIATES                                                                              49
 
COLUMN 1                      COLUMN 2 5-mSv Breastfeeding Activity  1-mSv Breastfeeding Activity TABLE 3 RADIO-NUCLIDE PHARMA-CEUTICAL        Requiring a Record l        Threshold for Instructions l  Breastfeeding Activity Thresholds (GBq)          (mCi)          (GBq)          (mCi)
C-11      choline            2            60            0.5            10 Cr-51      EDTA            30            800              6            200 F-18        FDG              1            30            0.2              6 Ga-67      citrate        0.08            2            0.02            0.4 Ga-68    octreotate          9            200              2            50 MIBG              1            40            0.3              8 I-123      OIH              2            40            0.3              8 NaIa          0.002          0.05          0.0004          0.01 I-124      NaIa        0.00003        0.0008        0.000006        0.0002 OIH            0.1              3            0.02            0.6 I-125 NaIa        0.00007        0.002        0.00001        0.0004 OIH            0.08            2            0.02            0.4 I-131 NaIa        0.000004        0.0001      0.0000009        0.00002 In-111 octreotate        0.9            30            0.2              5      0.04 GBq is to be administered.
WBC            0.08            2            0.02            0.4 Lu-177    octreotate        0.4            10            0.08            2 N-13        Any            10            400              3            70 O-15      water            10            300              2            60      The activity thresholds for requiring Ra-223    dichloride    0.000002        0.00005      0.0000004        0.00001 Rb-82    chloride          10            300              2            60      a record and requiring instructions DISIDA            0.2            6            0.05            1 DTPA DTPA aerosol 50 100 1000 4000 10 30 300 700 are exceeded.
glucoheptonate        20            600              5            100 HAM              0.2            7            0.05            1 MAA              2            60            0.4            10 MAG3              40            1000              8            200 Tc-99m      MDP              40            1000              9            200 MIBI            30            800              6            200 pertechnetate        0.5            10            0.1              3 PYP            0.7            20            0.1              4 RBC in vitro        50            1000            10            300 RBC in vivo          40            1000              8            200 sulfur colloid      0.5            10            0.1              3 WBC              0.8            20            0.2              4 Tl-201    chloride          2            50            0.4            10 Zr-89  panitumumab        0.01            0.3          0.002          0.07 RCD RADIATION PROTECTION ASSOCIATES                                                                                                                    50
 
WHAT IS THE RECOMMENDED INTERRUPTION TIME?
Table 3 provides the breastfeeding thresholds for maintaining records and providing instructions:
QBlrec = 0.01 GBq QBlins = 0.002 GBq With an administration of 0.04 GBq and a patient-specific effective half-life determination of 55 h, this patient is instructed to interrupt breastfeeding for
                              = 1.44 *
* ln      = 1.44
* 55 []
* ln 0.04 0.002 = 240 l
RCD RADIATION PROTECTION ASSOCIATES                                                                      51
 
ALTERNATIVE METHOD FOR DETERMINING FB Generalized and conservative approach for estimating the modifying factor for biokinetics For example, if pretreatment measurements indicate 70%
retention 48 hours after administration of I-131 (192-hr physical half-life) y-axis = 70%
x-axis = 48/192 = 0.25 FB = 0.8 RCD RADIATION PROTECTION ASSOCIATES  52
 
DETAILED MODIFYING FACTOR FOR OCCUPANCY, FO FO is the fraction of time the maximum bystander is exposed to the patient Occupancy and geometry can be taken together to help determine the maximally exposed individual The occupancy factor can be as simple as that shown earlier, i.e., FO = 8/24 = 0.33 Or it can be more detailed depending on the importance of early and late exposure potential (e.g., a radionuclide with short and long loss components)
Occupancy can be segment into (F1) short-term exposure (e.g., the initial period) and (F2) long-term exposure (e.g., the instruction period and thereafter); F1 and F2 are summed if for the same bystander F1 and F2 are essentially the fractions of time spent in close contact with the patient, modified by the expected loss of radioactive material prior to and during that exposure period (Appendix B)
RCD RADIATION PROTECTION ASSOCIATES                                                                        53
 
==SUMMARY==
 
Patient release is authorized if radiation dose to any other individual is not likely to exceed 5 mSv Written instructions must be provided to maintain ALARA if radiation dose to any other individual is likely to exceed 1 mSv Updated release methodology was presented Updated breastfeeding interruption/cessation guidelines (providing 1 mSv protection to the infant/child)
Allows for patient-specific exposure situations with modifying factors for biokinetics, occupancy, geometry, and attenuation Easily updated for emerging technologies RCD RADIATION PROTECTION ASSOCIATES                                                                    54
 
Public Feedback and Questions Contact Information and Resources Brian Allen, RES Technical Lead and COR Brian.Allen3@nrc.gov Katie Tapp, NMSS Technical Lead Katherine.Tapp@nrc.gov Harriet Karagiannis, Project Manager Harriet.Karagiannis@nrc.gov NRC Patient Release Website 56}}

Latest revision as of 18:36, 13 November 2024

Public Meeting on Information Request-Draft Regulatory Guide 8061, July 20, 2023
ML23198A203
Person / Time
Issue date: 07/20/2023
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ec Q Blr Q Blins

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