I-125 Prostate Therapy Regs.

[Patrick Muldoon <pmuldoon@mail.arc.nasa.gov>]

Zack,

Just to add to Andy's answer, when we used to do these procedures at the VA, the company would send approximately 6 extra seeds to be used if "cold" spots were located in the prostate at the time of the procedure.  We also had the authorized user physician in the OR while the procedure was being performed to evaluate the need for extra seeds and to sign the QM if these were deemed necessary.  This would also apply to seeds that are found in the bladder.  Either additional seeds could be added to make up for those lost, or the physician would decide that the lost seeds did not adversely affect the treatment and sign for that on the QM.  Finally, as weeks go by and the cancer begins to shrink, the seeds are known to migrate.  As far as unwanted exposure as the seeds migrate through the bladder, this is not much different than any other therapy as radiopharmaceuticals pass through the body and are excreted.

Hope these two answers help to address you questions.

Patrick

Zack wrote:

>If these seeds are implanted interstitially, how are they getting to a place

>to be "passed"?  Is there any other location that these seeds might end up

>being deposited by a patient that might end up being more of a problem than

>a strainer or the sewer system?   Does this indicate migration away from the

>treatment site and exposure to others, and what does that say about the

>adequacy of treatment dose?

>

Patrick S. Muldoon,
CHP
Radiation Safety Officer
M/S 19-21
NASA Ames Research Center
Moffett Field, California 94035-1000
(650) 604-3233