Information Notice No. 97-65: Failures of High-Dose-Rate Remote Afterloading (HDR) Device Source Guide Tubes, Catheters, and Applicators

                                   UNITED STATES
                           NUCLEAR REGULATORY COMMISSION
                              WASHINGTON, D.C.  20555

August 15, 1997

                                    AFTERLOADING (HDR) DEVICE SOURCE GUIDE
                                    TUBES, CATHETERS, AND APPLICATORS


All high-dose-rate (HDR) remote afterloader licensees


The U.S. Nuclear Regulatory Commission is issuing this information notice to alert addressees to
reports of failures in source guide tubes, catheters, and applicators used with HDR devices
supplied by the three major U. S. vendors of these devices.  Licensees should be aware of the
potential for similar failures during the course of patient treatments and the possible risk(s)
associated with the loss of containment of an HDR source.  It is expected that recipients will
review the information for applicability to their facilities and consider actions, as appropriate, to
avoid similar problems.  However, suggestions contained in this information notice are not new
NRC requirements; therefore, no specific action nor written response is required.

Description of Circumstances:

During the last several years, NRC has received reports of failures of HDR source guide tubes,
catheters, and applicators used to place and contain the HDR source during patient treatments. 
Most recently, the Food and Drug Administration (FDA) provided NRC with its inspection findings
documenting such failures for Nucletron Corporation devices.  A brief summary of the known
failures follows:

      1.    The FDA's March 1997, inspection findings at Nucletron Corporation included
            reported failures of Ring I/U tube applicators, Flexiguide cone catheters breaking
            inside patients, problems with numbers wearing off transfer tubes, catheter length
            variations, and one reported problem with an esophagal catheter.

      2.    A similar FDA inspection of Omnitron Corporation, in November 1993, found
            numerous reported failures with their Flexineedle applicators, and GYN and
            standard catheters.  Reports indicate that components of the Flexineedle
            applicators have separated inside patients and, in some cases, have not been

      3.    In 1993, an NRC licensee reported that a Gamma Med II source guide tube broke
            away from a vaginal cylinder.  This resulted in the HDR source being driven onto
            the table, rather than into the vaginal cylinder.  A subsequent check for defects by
            the licensee of all guide tubes and applicators, revealed that six bronchial, one
            tandem, and two intracavity tubes were defective..                                                            IN 97-65
                                                            August 15, 1997
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The causes for these defects in the applicators, guide tubes, and catheters have been variously
ascribed to design defects, errors in manufacturing, or improper sterilization procedures.  While
actions on the part of manufacturers have likely resulted in correction of most of the identified
problems, licensees performing HDR brachytherapy treatments should be aware of the potential
for failure of HDR device accessories.


Given that HDR device applicators, guide tubes, and catheters can fail suddenly and in an
unexpected manner, it is important that users of these components take appropriate precautions,
to the extent practicable, to protect their patients from injuries.  NRC is particularly concerned
about the possibility of both patients and health care providers receiving significant radiation
exposures.  The potential for significant radiation exposure could be reduced if licensees were
aware of the possibility of such failures and, as a direct result, were prepared to safely and
expeditiously handle the resulting emergency situation.

In recognition of the hazards associated with an event where an HDR source either becomes
stuck or detached during a patient treatment, NRC requested, in NRC Bulletin 93-01, that
licensees commit to providing written emergency procedures for responding to either of these
potential emergency situations.  This item was subsequently incorporated in Policy and Guidance
Directive FC 86-4 (Rev. 1) which provided NRC license reviewers with guidance for licensing HDR
device applications.  Some licensees responded to this request by stating that such an event is
improbable, since the source is always contained within the guide tube and/or applicator of the
device, thus, negating any need for establishing the requested emergency procedures.  Knowing
that there have been multiple reported failures of this containment system, licensees may wish to
reconsider the necessity of having preplanned emergency surgical procedures as an integral part
of their emergency response procedures for HDR patient treatments.  

Although the probability of a failure of the containment system simultaneous to the source sticking
or becoming detached would  be expected to be a very small,  the failure of a containment system
could, for example, increase the probability that the HDR source would become stuck or detached
by obstructing the path of the source, or an HDR source that became stuck or detached within the
source transport/containment system could stress the containment system, resulting in breaching
the containment.  Thus,  a failure of either the containment system or the source could easily
increase the probability for the failure of the other.

The FDA has the primary responsibility for regulating the design and manufacture of these HDR
guide tubes, applicators, and catheters.  Therefore, it is important that the FDA be notified of any
failures or defects with such devices, so that any problems, with a potential for patient injury, can
be corrected.  
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                                                            August 15, 1997
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Licensees should be aware that medical device user facilities are now subject to mandatory FDA
adverse event reporting requirements for medical devices.  Information concerning FDA's
mandatory reporting requirements can be obtained by contacting the Center for Devices and
Radiological Health, Office of Surveillance and Biometrics, Division of Surveillance Systems, at
(301) 594-2735.  Since the FDA mandatory reporting requirements may not be applicable to all
medical device events, FDA also depends on information voluntarily provided by device users
because they are often the first to recognize medical device-related hazards.  Any concerns that
licensees may have pertaining to the safety or quality problems associated with medical devices
can be voluntarily reported to the FDA by calling MedWatch at 1-800-FDA-1088.  Voluntary
reports can be submitted anonymously.

This information notice requires no specific action nor written response.  If you have any questions
about the information in this notice, please contact the technical contact listed below or the
appropriate NRC regional office.

                                    Donald A. Cool, Director
                                    Division of Industrial and 
                                      Medical Nuclear Safety
                                    Office of Nuclear Material Safety
                                      and Safeguards

Technical Contact: Robert L. Ayres, NMSS
                   (301) 415-5746

1.  List of Recently Issued NMSS Information Notices
2.  List of Recently Issued NRC Information Notices

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