United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 94-37: Misadministration Caused by a Bent Interstitial Needle During Brachytherapy Procedure


May 27, 1994



All U.S. Nuclear Regulatory Commission Medical Licensees authorized to use
brachytherapy sources in high-, medium-, and pulsed-dose-rate remote


NRC is issuing this information notice to alert NRC licensees of an incident
involving an interstitial needle bent inside the patient's body during a
high-dose-rate procedure with an Omnitron 2000 brachytherapy system.  The
bend in the Omnitron interstitial needle, through which the radioactive
source travels, prevented the source from retracting beyond the point of the
bend. This resulted in the actual radiation dose received by the patient
exceeding the prescribed dose by approximately 75 percent.  It is expected
that recipients will review this information for applicability to their
facilities and consider actions, as appropriate.  However, suggestions
contained in this information notice are not new NRC requirements; therefore,
no specific actions nor written response is required.

Description of Circumstances

On January 13, 1994, at the end of an interstitial lung treatment, the source
wire containing a 144.3 gigabecquerel (3.9 curie) iridium-192 source failed to
retract to the shielded storage position.  Members of the medical staff
followed appropriate emergency procedures and removed the needle from the
patient.  Licensee personnel noted a kink in the interstitial needle after
removal.  Once outside the patient's body, the source retracted into the
shielded position.  As a result of the stuck source, the dose to the last
treatment position was 17.32 gray (Gy) (1732 rads) versus the prescribed dose
of 10 Gy (1000 rads).  In addition, an area just below the last treatment
location received a dose of approximately 14 Gy (1400 rads) versus the 8 Gy
(800 rads) intended in the prescribed treatment plan.

The kink in the needle occurred at a location where the interstitial needle
extended beyond a biopsy needle to facilitate the insertion.  Under this
configuration, the biopsy needle acted as a sleeve covering approximately 75
percent of the interstitial needle.  The licensee's preliminary conclusion was
that the kink at the interface between the interstitial and biopsy needles was
caused by a sudden movement of the patient near the end of the treatment.  The
licensee reached this conclusion on the basis that X-rays taken just before
the treatment revealed no unusual conditions and the treatment was uneventful

9405230065.IN 94-37
May 27, 1994
Page 2 of 2

until the patient's sudden movement.  When the biopsy and interstitial needles
were withdrawn from the patient, the kink in the interstitial needle was
relieved somewhat, allowing the source to return to the storage position.
Early during the needle insertion process, it had been difficult to insert a
different Omnitron needle through the patient's rib cage to the treatment
site.  As a result, licensee physicians opted to use a biopsy needle, through
which the interstitial needle was placed in the desired location.  Believing
that the shielding provided by the biopsy needle would interfere with the
delivery of the radiation dose, a physician retracted the biopsy needle to
just outside the treatment site.


Needles and other accessories to high-dose-rate remote afterloading therapy
may be subjected to unusual mechanical stresses during patient treatment.
Each patient setup should be carefully evaluated to avoid or minimize the
potential for deformation of needles and other guides.  In particular,
reducing thickness or withdrawing another device in order to preserve dose
rate may not be in the best interests of safety.  In most instances, any
reduction in dose rate may be compensated by a modest increase in treatment
time.  If the use of extremely thin materials cannot be avoided, licensees
should ensure that their operating and emergency procedures are adequate to
prevent and mitigate the consequences of mechanical deformations in the path
of the source wire.  In such circumstances, surgical intervention may be
required and should be included in emergency plans as required in NRC
Bulletin 93-01.

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

                        original signed by
                        E. William Brach

                    Carl J. Paperiello, Director
                    Division of Industrial and
                      Medical Nuclear Safety
                    Office of Nuclear Material Safety
                      and Safeguards

Technical contacts:  Hctor Bermdez, RII
   (404) 331-7880

   James Smith, NMSS
   (301) 415-7904

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

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