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Re[2]: incontinent patient dosed with ~100 mCi of I-131
I will be out of the office from June 20 through July 4, returning July 5th.
Please contact Jennifer Smulling on x2978 if you need imediate assistance.
___________________________________________________________________________
Subject: RE: incontinent patient dosed with ~100 mCi of I-131
From: radsafe@romulus.ehs.uiuc.edu
Date: 06/20/00 09:12:23
This is a great topic. I appreciate all the comments. This case has many
gray areas.
Important clinical questions:
1. How incontinent is the patient? Many older patients, especially
females, wear Depends for occasional stress-induced (coughing, laughing,
exertion) incontinence. However, some patients rarely have an "accident".
If they do have an accident, they often lose only a small amount of urine.
2. What is the patient's assumed biological I-131 half-life? NRC
Regulatory Guide 8.39, Release of Patients Administered Radioactive
Materials, Appendix B, provides very conservative sample calculations. The
NRC's conservative estimate of the effective half-life of the extrathyroidal
component is 0.32 days.
Based on this information, I recommend the following:
1. Definitely admit the patient for therapy. No outpatient ablation in
this case.
2. If the patient is moderately or severely incontinent (requires frequent
diaper changes), place a foley bladder catheter. Have nursing personnel
instruct patient how to empty the collection bag. This eliminates health
physics personnel from repeatedly entering the room and risking spread of
contamination in unrestricted areas. If patient is mildly incontinent, have
patient collect the pads/diapers for storage and decay.
3. As always, highly encourage drinking extra fluids and urinating
frequently. To eliminate the need for nursing personnel to enter the room,
I recommend against starting an IV drip unless absolutely clinically
warrented. Discharge patient after 3 days. This represents 9 biological
half-lives using the extrathyroidal component.
4. Upon discharge, instruct patient to immediately change the pads/diapers
should there be a wetting incident. The patient is an adult, not a baby.
Therefore, he/she will know if they're wet. I recommend the patient dispose
of this waste in his/her regular household waste. At this point (4 days
post-dosing), most of the extrathyroidal I-131 has been excreted. Urinary
excretion after 9 effective half-lives have passed (3 days) will be
relatively minimal (less than 1 mCi).
5. I would not recommend canceling the ablation since the benefits of the
therapy far outweigh the potential complications.
Sincerely,
Mark D. Krueger, RPh, BCNP
CPT, MS
United States Army
Clinical Nuclear Pharmacist
Dwight D. Eisenhower Army Medical Center
Fort Gordon, GA 30905-5650
phone: (706) 787-2196
FAX: (706) 787-2181
E-mail: mark.krueger@se.amedd.army.mil
Disclaimer:
The opinions or assertions contained herein are the private views of the
author and are not to be construed as official or reflecting the views of
the US Department of the Army or the Department of Defense.
-----Original Message-----
From: David W Lee [mailto:lee_david_w@lanl.gov]
Sent: Monday, June 19, 2000 4:42 PM
To: Multiple recipients of list
Subject: RE: incontinent patient dosed with ~100 mCi of I-131
RADSAFERS:
Stupid question #3 or #4 so far on this thread. If this incontinent
patient's attending physicians already agree/know that the patient is
incontinent, what is so difficult about catheterizing the patient and
collecting the radioactive urine in a bag/bottle which could then be
periodically poured down the hospital commode by a hospital radiological
control technician supporting this operation?
Best regards David W. Lee, Radiological Engineering Team Leader, Los
Alamos National Laboratory (lee_david_w@lanl.gov), PH: (505) 667-8085;
FAX: (505) 667-9726
> I assume your patient has thyroid cancer, has undergone a sub-total
>thyroidectomy and you are treating her with 100 mCi (2.7 GBq or 2700 MBq)
of
>I-131 to ablate post-surgical thyroid tissue remnants, or you are treating
>post-thyroidectomy metastatic disease. In this case, you would expect the
>patient to excrete >95% of the administered activity, primarily through the
>urine. I would have a great deal of concern about potential deterministic
>radiation effects to the skin of the buttocks and genitals of this patient.
>NCRP Report #111 "Developing Radiation Emergency Plans for Academic,
Medical
>or Industrial Facilities" table 4.3 gives a skin contamination dose
>equivalent for I-131 of 1694 mSv per square centimetre per MBq per hour.
>
>During the first night after oral administration of the radioactivity, it
>would not be unusual for the patient to void 10% of the activity, which
>would be trapped over a surface area in her diaper of about 100 cm^2.
>Assuming the patient sleeps 8 hours with 10 mCi (370 MBq) or more of
>excreted I-131 in her diaper (direct contact with her skin), she could
>theoretically receive a skin dose of 50 Sv per cm^2 - which could lead to
a
>spectrum of nasty skin effects, including erythema, moist desquamation,
>total breakdown. The threshold dose for moist desquamation is 15 Sv. And
>that's just the skin dose for the first night. The skin in that area is
>already fragile and vulnerable to breakdown because of constant exposure to
>ammonia in the urine - have you ever seen a baby with diaper rash?? Very
>nasty and long-term effects for the patient, plus high potential for a
>successful medical malpractice suit against the physican and medical
>institution.
>
>If this were our patient, I would strongly recommend hospitalizing the
>patient for at least 48 hours so that she could be catheterised with the
>shielded "hot" urine collection bag emptied to the toilet every few hours
by
>trained nursing staff. I would make sure the patient is very well-hydrated
>(I.V. drip) and/or lots of liquid orally to flush out of her system the
>radioactivity not taken up by the target tissue As a matter of fact, I have
>done this for an incontinent patient in diapers being treated for Graves
>disease with much less activity - when we expected only about 5 mCi
excreted
>via the urine.
>
>Regards,
>
>Karin
>Gordon*********************************************************************
*
>Karin Gordon RTR, RTNM, RTT
>Radiation Safety Coordinator
>Winnipeg Regional Health Authority
>Health Sciences Centre
>GC-214, 820 Sherbrook Street
>Winnipeg, Manitoba
>CANADA, R3A 1R9
>
>phone (204) 787-2903
>fax (204) 787-1313
>e-mail kgordon@hsc.mb.ca
>************************************************************************
>Message-----
>From: Douglas Simpkin [mailto:dsimpkin@execpc.com]
>Sent: Monday, June 19, 2000 12:37 PM
>To: Multiple recipients of list
>Subject: incontinent patient dosed with ~100 mCi of I-131
>
>Folks:
>
>Ignorant question time!
>
>Our nuclear medicine physicians are talking about treating an incontinent
>patient with ~100 mCi of I-131. Even if we hold her (and her diapers) in
>the hospital for a few days, she'll still be generating I-131 waste once
>she gets home.
>
>How would others handling this?
>1. Ignore waste she generates at home, and hope the landfill doesn't
>monitor.
>2. Have her collect her own waste for decay in her basement?
>3. Have her collect her own waste, and we then pick up the trash for
>decay-in-storage here. What are the DOT repercussions of me having a
>trunk-full of hot Depends?
>
>Any comments?
>Thanks,
>Doug
>Douglas J. Simpkin, Ph.D., D.A.B.R.
>St. Luke's Medical Center
>2900 West Oklahoma Avenue
>Milwaukee, WI 53215
>phone: (414)649-6457
>fax: (414)649-5118
>email: dsimpkin@execpc.com
>
>************************************************************************
>The RADSAFE Frequently Asked Questions list, archives and subscription
>information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html
>
DAVID W. LEE, CHP
Los Alamos National Laboratory
Radiation Protection Services
Radiological Engineering Team Leader
ESH-12, MS K483
Los Alamos, NM 87545
PH: (505) 667-8085
FAX: (505) 667-9726
lee_david_w@lanl.gov
************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html
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The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html