United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 86-84: Rupture of a Nominal 40-Millicurie Iodine-125 Brachytherapy Seed Causing Significant Spread of Radioactive Contamination

                                                            SSINS No.:  6835
                                                            IN 86-84 

                                UNITED STATES
                           WASHINGTON, D.C. 20555

                             September 30, 1986

Information Notice No. 86-84:   RUPTURE OF A NOMINAL 40-MILLICURIE 
                                   IODINE-125 BRACHYTHERAPY SEED CAUSING 
                                   SIGNIFICANT SPREAD OF RADIOACTIVE 


All NRC medical institution licensees. 

Purpose: This notice is to alert licensees of a spread of iodine-125 
contamination resulting from the inadvertent cutting of the seed 
encapsulation during removal of the seed from Heyer-Schulte coaxial 
catheters. The seed was one of eight seeds used for brachytherapy treatment 
of a brain tumor. It is expected that, licensees will review this 
information for applicability to their facilities and consider actions, if 
appropriate, to preclude similar problems from occurring at their 
facilities. However, suggestions contained in this information notice do not 
constitute NRC requirements; therefore, no specific action or written 
response is required. 

Description of Circumstances: 

The seeds, which are manufactured by 3M Company, are intended to be 
reusable because of the initial high activity of the seeds (40 millicuries 
per seed). Users of the seeds are motivated to reuse them for several 
patients because of the relatively high cost of the seeds. The seeds are 
removed from the old catheters and loaded into new catheters for implant 
into other patients. It was during removal of the seeds from the catheter 
that one of the seeds ruptured. The rupture was believed to have been caused 
by cutting the catheter to free the seeds with a sharp object, such as a 
razor blade or scissors. The licensee did not know that a seed had been 
ruptured. The seeds, including the ruptured seed, were reloaded into new 
catheters and implanted into a patient. As a result, the patient sustained a 
thyroid burden of about 557 microcuries and a radiation dose to the thyroid 
of about 2087 rads. 

Licensee personnel were not immediately aware that one or more seeds had 
ruptured until they found iodine-125 contamination in a source/transport 
bucket stored in the brachytherapy source storage room (BSSR) on the day 
after the implant into a patient following reloading of the seeds into the 
new catheters. 


                                                  IN 86-84 
                                                  September 30, 1986 
                                                  Page 2 of 2 

The seeds were removed from the old catheters ani loaded into new catheters 
in the BSSR an area not ventilated by a fume hood. Consequently, 
approximately 60 hospital personnel, including those involved in cleanup 
operations, received thyroid uptakes of iodine-125 from 0.04 to 209 
nanocuries. A proper radiation survey meter was used, but the high 
background radiation in the BSSR masked the positive indication of 


The isolated incident described is the only incident of its kind known by 
the NRC involving high-activity iodine-125 seeds. However, there have been 
several other similar incidents involving the use of low-activity seeds 
containing 0.1 to 1 millicuries used as permanent implants. Both types of 
seeds are manufactured by 3M Company. 

The risk of iodine-125 seed rupture is relatively high when the seeds are 
used for several patients. The incident was caused because: 

.    the seeds are susceptible to damage from sharp tools such as razor 
     blades or scissors 

.    the discolored or stained condition of the catheters after use in 
     therapy makes viewing of the seeds difficult 

The consequences of the seed rupture (involving patient exposures, other 
personnel iodine-125 uptakes, and facility contamination) can be mitigated 
by performing (1) adequate radiation surveys of the work area, using a 
radiation detection instrument capable of detecting the low-energy photons 
(average of 28 keV), (2) the proper handling of tools used to remove the 
seeds from the catheters, and (3) leak tests of the seeds. Also, 
contamination of the facilities probably can be prevented if the seed 
removal operation is performed in a fume hood. Personnel uptakes of the 
radioactive materials and facility contamination also might be mitigated by 
using radiation safety procedures designed to detect seed leakage promptly. 

No specific action or written response is required by this notice. If you 
have any questions regarding this information notice, please contact the 
Regional Administrator of the appropriate NRC regional office or this 

                                   James G. Partlow, Director 
                                   Division of Inspection Programs 
                                   Office of Inspection and Enforcement 

Technical Contacts:  J. Metzger, IE 
                     (301) 492-4947 

                     H. Karagiannis, IE 
                     (301) 492-9655 

Attachment:  List of Recently Issued IE Information Notices
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