NRC'S NEW PATIENT RELEASE REGULATION

[ASOLUTION8@aol.com]

I raised an issue on RADSAFE that seems to need some clarification.  I
discussed a situation in which a patient might be release shortly after
receiving a 150 mCi (5550 MBq) therapeutic administration of iodine-131.  I
was discussing the NRC's new regulation on the release of patients who have
been administered radioactive materials.  The NRC published an amendment of
its regulations on January 29, 1997 [62 Federal Register 4120].  The new
regulation is effective on May 29.

THE OLD 30 mCi (1110 MBq) WILL CEASE TO EXIST ON MAY 29.  Some people
responded that you cannot release a patient if the activity in the patient
exceeds 30 mCi (1110 MBq) or if the dose rate at 1 meter exceeds 5 mrem/hr
(.05 mSv/hr).  That is the old rule.  That rule will cease to exist for NRC
licensees on May 29.  

WHAT IS THE NEW RELEASE CRITERION?  You may release a patient is the dose to
any other individual exposed to the patient is not likely to exceed 0.5 rem
(5 mSv).

BUT DOESN'T THIS EXCEED THE PUBLIC DOSE LIMIT OF 0.1 REM (1 mSv)?  While the
annual public dose limit is usually 0.1 rem (1 mSv), NRC regulations, NCRP
recommendations, ICRP regulations, and draft EPA federal guidance all allow
0.5 rem (5 mSv) in a year in special circumstances where the exposure can be
justified and where the circumstances are not likely to be repeated.  The NRC
says the 0.5 rem (5 mSv) limit is justified, meets the criteria established
by those bodies,  and is therefore acceptable. 

UNDER THE NEW RULE, IS THE RELEASE LIMIT HIGHER OR LOWER?  It depends on the
radionuclide.  Sometimes you can release a patient with more than 30 mCi
(1110 Bq).  Sometimes release with 30 mCi (1110 Bq) would be a violation.
 Sometimes you can release a patient if the dose rate at one meter exceeds 5
mrem/hr.  Sometimes that would be a violation.

WHAT'S AN EXAMPLE OF A RADIONUCLIDE WITH A LOWER RELEASE LIMIT?  Iodine-125.
 Release based on 30 mCi (1110 MBq) would be a violation.  Release based on 5
mrem/hr (0.05 mSv/hr) would also be a violation.     

WHAT ABOUT IODINE-131?  At this time it is not possible to be sure, but early
drafts of the NRC's guidance on the rule indicate that you will probably be
able to continue using the 30 mCi (1110 MBq) or 5 mrem/hr (0.05 mSv/hr)
limit.

CAN YOU RELEASE AN IODINE-131 THERAPY PATIENT IMMEDIATELY AFTER RECEIVING AN
ADMINISTRATION OF 100 mCi (3700 MBq)?  Perhaps yes.  Release with larger
activities than generally allowed may be authorized on the basis of
patient-specific calculations according to drafts of the guidance being
prepared.  Records of these calculations would have to be maintained for
inspection.

DO THE NEW REQUIREMENT FOR WRITTEN INSTRUCTIONS AND RECORD KEEPING AFFECT
DIAGNOSTIC ADMINISTRATIONS?  Absolutely yes, particularly as they apply to
women patients who could be breast-feeding.

IS THERE AN EASY WAY TO FIGURE OUT WHEN PATIENTS CAN BE RELEASED, DO THE
PATIENT-SPECIFIC CALCULATIONS WHEN NEEDED, MAINTAIN THE NEWLY REQUIRED
RECORDS, AND PROVIDE WRITTEN INSTRUCTIONS WHEN NECESSARY?  Absolutely yes.
 My company is developing SAFE RELEASE SOFTWARE to do all that for you.  It
will be released shortly after the NRC publishes its final guidance on the
rule, now estimated for about March 17.  E-mail me at ASOLUTION8@AOL.COM if
you would like to receive more detailed information on the software.

Michael McGuire, Project Manager
Simplified Solutions Software, Inc.
1466 Chapin Street NW, Suite 1
Washington, DC 20009
ASOLUTION8@AOL.COM