Records of release of patients are required, if the TEDE is calculated by
using the retained activity rather than the administered activity, using an
occupancy factor less than 0.25 at 1 meter, using a biological or effective t1/2
or considering the shielding by tissue. Records are also required if instruc-
tions are given to a breast-feeding woman who may give a TEDE exceed-
ing 500 mrem (5 mSv) to the infant from continuous breast-feeding
(10CFR35.2075). Table 16.3 gives the activity limits that require record-
keeping in the case of breast-feeding.
Recordkeeping
Records must be maintained for the receipt, storage, and disposal of
radioactive materials, and also for various activities performed in the radi-
ation laboratories. According to the NRC regulations, these records must
contain specific information and be kept for a certain period of time. Table
16.4 lists different records that are required by the NRC and the period of
time to be kept.
Medical Uses of Radioactive Materials 291Table16.3. Limits of activities that require instructions to breast-feeding patients
and recordkeeping.*
Activity above
which Activity above
instructions are which record is Recommended
needed mCi needed mCi duration of cessation of
Radiopharmaceutical (MBq) (MBq) breast-feeding
(^131) I-NaI 0.0004 (0.01) 0.002 (0.07) complete cessation
(^123) I-NaI 0.5 (20) 3 (100) —
(^131) I-MIBG 2 (70) 10 (400) 12 hr (4 mCi/150 MBq)
99mTc-DTPA 30 (1000) 150 (6000) —
99mTc-MAA 1.3 (50) 6.5 (200) 12.6 hr (4 mCi/150 MBq)
99mTc-Pertechnetate 3 (100) 15 (600) 12 hr (12 mCi/440 MBq)
99mTc-DISIDA 30 (1000) 150 (6000) —
99mTc-Glucoheptonate 30 (1000) 170 (6000) —
99mTc-Sestamibi 30 (1000) 150 (6000) —
99mTc-MDP 30 (1000) 150 (6000) —
99mTc-PYP 25 (900) 120 (4000) —
99mTc-RBC in vivo 10 (400) 50 (2000) 6 hr (20 mCi/740 MBq)
99mTc-RBC in vitro 30 (1000) 150 (6000) —
99mTc-Sulfur colloid 7 (300) 35 (1000) 6 hr (12 mCi/440 MBq)
99mTc-MAG3 30 (1000) 150 (6000) —
99mTc-WBC 4 (100) 15 (600) 12 hr (12 mCi/440 MBq)
(^67) Ga-Citrate 0.04 (1) 0.2 (7) 1 wk (0.2 mCi/7 MBq)
(^111) In-WBC 0.2 (10) 1 (40) 1 wk (0.5 mCi/20 MBq)
- NRC regulatory Guide 8.39.