Transcript Iodine-131 Therapy and the Dialysis Patient

Iodine-131 Therapy
and the Dialysis Patient
M.J. Bohan and R.L. Richardson
Yale-New Haven Hospital
Radiation Safety Office
The Problem

Thyroid cancer and hyperthyroid patients with
renal failure present a number of radiation
safety and medical physics challenges

Unfortunately, there is not a lot of published
sources of information in the literature that
address the issues presented by these
patients
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Health Physics Issues
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Potential for increased occupational
exposures
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Potential for contamination control and
waste disposal issues
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Early patient release issues - dose to
family and the public
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Medical Physics Issues
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How much longer in advance should you
recommend iodine dietary restrictions and
removal of replacement hormone?

Uptake studies may be misinterpreted due to
poor systemic washout at 24 - 48 hrs
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Altered excretion kinetics results in greatly
increased whole body dose
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Case Study Number 1
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Female thyroid cancer patient with end stage
renal disease on hemodialysis
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Written directive - Administer 5.6 GBq (152 mCi)
Hemodialysis on regular schedule at 48 hrs post
administration
Patient isolated at hospital for first two dialysis
sessions and then was followed as an outpatient
for the next week
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Patient WB ∞ Dose Estimates
Infinite Whole Body
Dose Estimates
Normal - 5.62 GBq
Patient (152 mCi)
Hemodialysis
Effective
Hemodialysis
Actual
Eff. T 1/2
(days)
Dose
(Gy)
0.33
0.17
1.5
0.78
Field
Measurements
1.6
MIRD - Pamphlet 11 (1975), I-131 (TB <-- TB), 9.9E-6 rad/uCi-hr
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Case Study Number 2

Two years later, same patient, now on
peritoneal dialysis
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Written directive - Administer 11 GBq (296 mCi)
Peritoneal dialysis on regular schedule at home
Patient isolated dialysis wastes in garage
CAPD every 4-6 hours during the day
NIPD at night only, for first two days
After day 2, CCPD continuously
(CAPD - Continuous Ambulatory Peritoneal Dialysis)
(NIPD - Nocturnal Intermittent Peritoneal Dialysis)
(CCPD - Continuous Cycle Peritoneal Dialysis)
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Patient WB ∞ Dose Estimates
Infinite Whole Body
Dose Estimates
Normal - 11 GBq
Patient (296 mCi)
Peritoneal Dialysis
Effective
Peritoneal Dialysis
Actual
Eff. T 1/2
(days)
Dose
(Gy)
0.33
0.33
1.5
1.5
Field
Measurements
1.8
MIRD - Pamphlet 11 (1975), I-131 (TB <-- TB), 9.9E-6 rad/uCi-hr
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Case Study Number 3

New male patient on peritoneal dialysis with
about 15% of normal renal function
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Written directive - Administer 1.2 GBq (31.3 mCi)
Peritoneal dialysis on regular schedule at home
Patient isolated dialysis wastes on porch
NIPD at night only
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Hours
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Patient WB ∞ Dose Estimates
Infinite Whole Body
Dose Estimates
Normal - 1.2 GBq
Patient (31.3 mCi)
Peritoneal Dialysis
Effective
Peritoneal Dialysis
Actual
Eff. T1/2
(days)
Dose
(Gy)
0.33
0.035
1.5
0.16
T1/2 ≈ 1 day
Field
Measurements
0.12
MIRD - Pamphlet 11 (1975), I-131 (TB <-- TB), 9.9E-6 rad/uCi-hr
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Lessons Learned

If you give a dialysis patient a dose which would be appropriate
for a normal patient, the whole body dose is extremely high
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Because the I-131 continues to re-circulate in dialysis patients,
you should be able to titrate the administered dose based on the
calculated whole body dose and lower their dose without
compromising their thyroid uptake
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If patients have partial kidney function, you should take it into
account when calculating the adjusted dose
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Reducing the administered dose also helps with patient release
issues
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Consider Changing the
Hemodialysis Scheduling
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Modification of the hemodialysis schedule will
dictate the administered dose
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Schedule 1: 48 hrs post administration, MWF
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Schedule 2: 48 hrs @ 24 hr post adm, TThSaMWF
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Schedule 3: 24 hrs @ first 3 days then release from isolation
with outpatient hemodialysis on Sa, then back to normal MWF
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Estimated Whole Body Doses for 100 mCi Rx
Normal Pt. - 0.11 Gy
48 hr @ 48 hr - 0.80 Gy (14%)
48 hr @ 24 hr - 0.59 Gy (19%)
24 hr @ 1st 3days - 0.47 Gy (23%)
Mon
Wed
Fri
Sun
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Fri
Sun
Tue
Thur
Contamination/Waste Issues
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Hemodialysis systems are self contained and use
copious amounts of water to wash the blood.
Residual contamination levels are usually low and
easily cleaned up. Cartridges and tubing will retain
low levels of activity and should be held for decay
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Occupational Dose Issues
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Hemodialysis nurses must stay close to the dialysis
machine and service it periodically
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You need to train them in time and distance controls
to minimize their occupational dose
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Measured Occupational Doses
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5.6 GBq (152 mCi) on in-patient hemodialysis
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First Dialysis - Nursing Dose 18 mrad
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Second Dialysis - Nursing Dose 42 mrad
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References
Jimenez, R.G., et al., Iodine-131Treatment of Thyroid Papillary Carcinoma in patients Undergoing
Dialysis for Chronic Renal Failure: A Dosimetric Method, Thyroid, Vol. 11, NO. 11, 2001
Mars, D.R., et al, Iodine Retention and Thyroid Dysfunction in Patients on Hemodialysis and Continuous
Ambulatory Peritoneal Dialysis, Am. J. Kidney Dis., June 1986, 7(6):471-6)
Magne, N., et al, Disposition of Radioiodine 131-I therapy for Thyroid Carcinoma in a Patient with
Severely Impared Renal Function on Chronic Dialysis: A Case Report, Jpn. J. Clininal Oncology 2002;
32(6) 202-205
Kaptein, E.M., Radioiodine Dosimetry in Patients with End-stage Renal Disease Receiving Continuous
Ambulatory Peritoneal Dialysis Therapy, J Clin Endocrinol Metab. 2000 Sep;85(9):3058-64
Sisson, J.C., Practical Dosimetry of 131-I Patients with Thyroid Carcinoma, Cancer Biotherapy &
Radiopharmaceuticals, Vol. 17, No. 1, 2002
Thomas, S.R., Options for Radionuclide Therapy: From Fixed Activity to Patient-Specific Treatment
Planning, Cancer Biotherapy & Radiopharmaceuticals, Vol. 17, No. 1, 2002
Kaptein, E.M., Radioiodine Dosimetry in Patients with End-Stage Renal Disease Receiving Continuous
Ambulatory Peritoneal Dialysis Therapy, The Journal of Clinical Endocrinology & Metabolism, Vol. 85,
No. 9, 2000
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