Patient Release Calculator – Medical Physics Consultants

MPC I-131 Patient Release Calculations Program

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Select Treatment Type

Was the patient given written instructions?

Date

Select Release Limit (NRC Default: 500 mRem)

mRem

Patient Specific Values

Activity Administered

[mCi]

Measured Uptake Value (NRC Default: 5 %)

Select Care Given (NRC Default: Normal)

Placeholder

Contact @ 1Meter During 1st 8hr (NRC Default: 6 hr)

Occupancy factor for first 8 hours

Result

[mRem]

I-131 Patient Release Calculation

Date
Patient given written instructions
Treatment Type	Post-Thyroidectomy for Thyroid Cancer
Release Limit	100 mRem
Q_o =	Activity Administered: 3 [mCi]
F2 =	Measured Uptake Value: 25%
Care Given	25%
Contact @ 1Meter During 1st 8hr	3hr

34.6	Conversion Factor of 24 Hrs/Day Times Total Integration Of Decay (1.44)
Γ =	1.7 Exposure Rate Constant For A Point Source [R/mCi x hr] at 1 cm
Q_o	3 Initial Activity At The Start Of The Time Interval [mCi]
F₁	0.97
T_1eff	0.32
F₂	0.03
T_2eff	7.3
DCF	53 [rem/mCi]
D(t))	Accumulated Dose Estimated To Member Of Public Other Than Patient 0.00667589 [rem]
D(t)) result	6.7 [mrem]

Regulatory Guide 8.39 Rev 1 Equation B.5 + Equation B.6

D(t)) = [(34.6 * Γ * Qo )/(100^2)] * [E1Tp(0.8) * (1-exp(-.693(.33)/Tp)) + exp(-.693(.33)/Tp)*E2*F1*T1eff + exp(-.693(.33)/Tp)*E2*F2*T2eff] + Q(10-5)(DCF) Based on and consistent with NUREG -1556, Volume 9, Appendix U
https://www.nrc.gov/docs/ML1923/ML19232A081.pdf