Iodine-131 Therapyand the Dialysis Patient

M.J. Bohan and R.L. Richardson

Yale-New Haven Hospital

Radiation Safety Office

YNHH RSO - HPS 2006

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

YNHH RSO - HPS 2006

Health Physics Issues Potential for increased occupational

exposures

Potential for contamination control and waste disposal issues

Early patient release issues - dose to family and the public

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Medical Physics Issues 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

Altered excretion kinetics results in greatly increased whole body dose

YNHH RSO - HPS 2006

Case Study Number 1 Female thyroid cancer patient with end stage

renal disease on hemodialysis

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

YNHH RSO - HPS 2006

YNHH RSO - HPS 2006

Patient WB ∞ Dose EstimatesInfinite Whole Body

Dose Estimates

Eff. T 1/2

(days)

Dose

(Gy)

Normal - 5.62 GBq

Patient (152 mCi) 0.33 0.17

Hemodialysis

Effective 1.5 0.78

Hemodialysis

ActualField

Measurements 1.6MIRD - Pamphlet 11 (1975), I-131 (TB <-- TB), 9.9E-6 rad/uCi-hr

YNHH RSO - HPS 2006

Case Study Number 2 Two years later, same patient, now on

peritoneal dialysis 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)

YNHH RSO - HPS 2006

YNHH RSO - HPS 2006

Patient WB ∞ Dose EstimatesInfinite Whole Body

Dose Estimates

Eff. T 1/2

(days)

Dose

(Gy)

Normal - 11 GBq

Patient (296 mCi) 0.33 0.33

Peritoneal Dialysis

Effective 1.5 1.5

Peritoneal Dialysis

ActualField

Measurements 1.8MIRD - Pamphlet 11 (1975), I-131 (TB <-- TB), 9.9E-6 rad/uCi-hr

YNHH RSO - HPS 2006

Case Study Number 3 New male patient on peritoneal dialysis with

about 15% of normal renal function

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

YNHH RSO - HPS 2006

Hours

YNHH RSO - HPS 2006

Patient WB ∞ Dose EstimatesInfinite Whole Body

Dose Estimates

Eff. T1/2

(days)

Dose

(Gy)

Normal - 1.2 GBq

Patient (31.3 mCi) 0.33 0.035

Peritoneal Dialysis

Effective 1.5 0.16

Peritoneal Dialysis

Actual

T1/2 ≈ 1 day

Field

Measurements 0.12MIRD - Pamphlet 11 (1975), I-131 (TB <-- TB), 9.9E-6 rad/uCi-hr

YNHH RSO - HPS 2006

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

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

If patients have partial kidney function, you should take it into account when calculating the adjusted dose

Reducing the administered dose also helps with patient release issues

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Consider Changing the Hemodialysis Scheduling Modification of the hemodialysis schedule will

dictate the administered dose

Schedule 1: 48 hrs post administration, MWF

Schedule 2: 48 hrs @ 24 hr post adm, TThSaMWF

Schedule 3: 24 hrs @ first 3 days then release from isolation with outpatient hemodialysis on Sa, then back to normal MWF

YNHH RSO - HPS 2006

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 Fri Sun Tue Thur

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Contamination/Waste Issues

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

YNHH RSO - HPS 2006

Occupational Dose Issues Hemodialysis nurses must stay close to the dialysis

machine and service it periodically

You need to train them in time and distance controls to minimize their occupational dose

Measured Occupational Doses

5.6 GBq (152 mCi) on in-patient hemodialysis

First Dialysis - Nursing Dose 18 mrad

Second Dialysis - Nursing Dose 42 mrad

YNHH RSO - HPS 2006

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