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United States Nuclear Regulatory Commission - Protecting People and the Environment


                                                            OMB No. 3150-0012
                                                            NRCB 93-01

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

                                April 20, 1993


Addressees -      Brachytherapy Licensees Authorized to Use Afterloading 
                  Brachytherapy Unit(s) Capable of Delivering Dose Rates
                  Greater than 500 RADS (centigray) per Hour at 1 Centimeter


The U.S. Nuclear Regulatory Commission (NRC) is issuing this Bulletin: (1) to
notify addressees about the risk involved in releasing brachytherapy patients
without positive assurance that all implant material has been removed before
the patient's release, and the need to plan and train for both normal and
emergency procedures; (2) requesting that all addressees take the actions
specified below; and (3) requiring that all addressees provide the U.S.
Nuclear Regulatory Commission with a report stating whether the requested
actions have been taken or, if not applicable, state why the requested actions
do not apply. 

Description of Circumstances

According to information received by the NRC, an outpatient being treated with
an Omnitron Model 2000 remote afterloading unit at the Indiana Regional Cancer
Center (IRCC) in Indiana, Pennsylvania, of Oncology Services Corporation was
returned to a nearby nursing home, after treatment, with the radioactive
source remaining in her body.  The treatment took place on November 16, 1992,
and the patient died on November 21, 1992.  The cause of death of this
patient, as listed in the official autopsy report, is "Acute Radiational
Exposure And Consequences Thereof."  Until the source, approximately 4 curies
of iridium-192, was recovered after the patient's death, it subjected nursing
home residents and staff, as well as visitors, to radiation exposure. 
Radiation doses to the 94 individuals associated with the event ranged from 40
mrem to 22 rem.  

An investigation after the patient's death determined that IRCC personnel
experienced difficulty with source placement in one of the patient's five
treatment catheters.  The investigation found that a short piece of the cable
containing the iridium source had broken off and remained in one of the 
catheters.  The investigation also found that, although a wall-mounted area 
monitor alarmed at various times when the source should have been retracted,
the licensee's staff believed the area monitor was emitting a false signal and
chose to ignore it.  Also, no survey of the patient was performed by the 


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licensee, using a hand-held survey instrument, despite the area radiation
alarm condition.

A second incident was reported by Oncology Services Corporation on December 7,
1992.  A subsequent investigation found that a source again separated from the
drive cable on an Omnitron Model 2000 Unit, located at the licensee's Greater
Pittsburgh Cancer Center during brachytherapy treatment of a patient, and
lodged in the catheter, external to the patient.  The investigation determined
that the physicist detected the source separation during the treatment after
hearing an audible alarm from the remote afterloader and observing the area
radiation monitor alarm; he confirmed the source had not been fully retracted
using a portable survey meter and, thereafter, cut the catheter behind the
source and immediately removed the patient from the treatment room.  The
remaining portion of the catheter was then removed from the patient, and both
the catheter and patient were again scanned with a survey instrument, to
confirm that no part of the source remained within the catheter or patient. 
In this incident, the licensee's staff reacted promptly and appropriately, and
no excessive unintended exposures were received by either the patient or the


Irrespective of the terminology used by the remote afterloading device
manufacturer, if the device is capable of using a single source to produce
exposure rates in excess of 500 rads (centigray) per hour at one centimeter,
then this Bulletin applies.  Thus, for the purposes of this Bulletin, all
remote afterloading brachytherapy units capable of producing exposure rates in
excess of 500 rads (centigray) per hour at one centimeter will be referred to
as High-Dose-Rate (HDR) afterloaders.  However, NRC is aware of one special
type of remote afterloading device, commonly known as a pulsed dose rate
afterloader, that uses a single source capable of delivering dose rates up to
4800 rads (centigray) per hour, but is used to provide the equivalent of a low
dose treatment by inserting the source for a given fraction of each hour.  For
this special class of device, a licensee may submit an alternative, to the
procedure set forth in item 3, for insuring that control of the source is
maintained during treatment.  Any such alternative submitted will be carefully
evaluated for adequacy in maintaining control of the source.

NRC and the U. S. Food and Drug Administration (FDA) are conducting ongoing
investigations of the cause of the source wire failures associated with the
Omnitron Model 2000 Unit.  Until complete failure analysis information is
available, all patient treatments using this manufacturer's system must be
viewed as having a high risk for similar failures.  Although NRC has no recent
reports of such failures of other HDR models, similar failures are possible. 
For example, an incident occurred in August, 1988, where, because of an
incomplete weld, the end cap of a Nucletron MicroSelectron-HDR became detached
from the source capsule and resulted in three out of seven iridium-192
elements inside the capsule being deposited in both the head and close-ended
applicator of the HDR.  Given the severe consequence associated with loss of
control of one of these high-activity sources, users of all HDRs need to be
especially vigilant, in all their operations, to minimize the effects of any
machine or procedural errors that could lead to loss of control of the source.

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Based on what is presently known about the Indiana, Pennsylvania incident, it
is clear that if radiation surveys of the patient had been made with a hand
held survey instrument, before releasing the patient from the facility, the
consequences of that incident would have been largely avoided.  Although rare,
the loss of control of one or more of these high-activity radiation sources
has great potential for causing injury or death to patients, workers, and
members of the public.  

Requested Actions

Because the consequences of such a loss of control are so severe, NRC, through
this Bulletin, is alerting appropriate medical licensees and expects them to
implement the following measures to minimize the possibility of such an event
occurring again.  Therefore, licensees using HDR afterloaders are requested to
either immediately implement the following actions in conjunction with any use
of the unit and to respond in writing, stating their commitment to these
actions or, else, stating why these requested actions do not apply to their

1.    In accordance with 10 CFR 35.404(a), following removal of the source,
      the licensee shall make a radiation survey of the patient with an
      appropriate radiation detection survey instrument, as specified in 10
      CFR 35.420, to confirm that all sources have been removed.  For surveys
      associated with HDR procedures, the licensee must use a portable
      radiation measurement survey instrument, capable of measuring dose rates
      of 1 millirem per hour to at least 1000 millirem per hour.  It is
      important to use calibrated survey instruments with appropriate
      sensitivity, since the high exposure rates associated with these sources
      can easily overload some survey instrument detectors, resulting in a
      false low reading.  This survey of the patient must be done whether or
      not there is any indication of radiation levels provided by an area
      radiation monitor.  The surveys shall be performed immediately after
      completion of the therapy procedure before removal of the patient from
      the treatment room, and appropriately documented in accordance with 10
      CFR 35.404(b).

      The required area monitor provides an immediate indication of a possible
      problem and thus serves a useful function as an early warning device. 
      This area monitor will provide a visible indication of an exposed or
      partially exposed source, and must be observable immediately on entry
      into the treatment vault.  It must be equipped with an independent
      source of backup power and checked with a dedicated check source for
      proper operation each day of use of the HDR device.  However, it has
      neither the accuracy nor the sensitivity required to comply with the
      survey requirements of 10 CFR 35.404(a).

2.    A licensee shall have written emergency procedures describing actions to
      be taken, including surgical intervention, should the source not return
      to the shielded container at the conclusion of treatment.  The licensee
      shall not begin any treatment procedure for which a decoupled or jammed
      source cannot be removed expeditiously from the patient and placed in a
      shielded condition.  The licensee shall ensure that appropriate staff
      and equipment are available immediately, at the location that the HDR .

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      procedure is performed, to implement the written emergency procedures. 
      Equipment shall include shielded storage containers, remote handling
      tools, and, if appropriate, supplies necessary to surgically remove
      applicators or sources from the patient, to include scissors and cable
      cutters.  The emergency source removal procedure should minimize
      exposure to health care personnel while maximizing safety of the

3.    During all patient treatments, both the authorized user and either the 
      medical physicist or radiation safety officer must be physically
      present.  Physical presence, for this purpose, is defined as within
      audible range of normal human speech. 

4.    The licensee shall ensure that personnel are trained in both the routine
      use of the HDR afterloading device and emergency procedures necessary to
      return the source to a safe condition.  Training shall be provided
      immediately to new personnel and periodic retraining, not to exceed 12
      month intervals, shall be provided for all personnel.  The licensee
      shall retain records of this training for a period of 3 years. 

Reporting Requirements

All addressees are required to report, in writing, within 30 days of the date
of this Bulletin, whether the actions described in this Bulletin have been    
taken, or stating why they do not apply to their facility.

Address the required written reports to the U.S. Nuclear Regulatory
Commission, ATTN:  Document Control Desk, Washington, D.C. 20555, under oath
or affirmation, under the provisions of Section 182a, of the Atomic Energy Act
of 1954, as amended.  In addition, submit a copy to the appropriate NRC
Regional Administrator.

This request is covered by Office of Management and Budget Clearance Number
3150-0012, which expires June 30, 1994.  The estimated average number of
burden hours is 20 person-hours per licensee response to this Bulletin. (This
estimate of the average number of burden-hours pertains only to the
preparation of the required report and does not include implementation of the
requested actions.)  Send comments about this burden estimate or any other
aspect of this collection of information, including suggestions for reducing
this burden, to the Information and Records Management Branch, Division of 
Information Support Services, Office of Information Resources Management, 
U.S. Nuclear Regulatory Commission, Washington, D.C.  20555, and to the Office
of Information and Regulatory Affairs, (3150-0012) NEOB-3019, Office of
Management and Budget, Washington, DC 20503.

Licensees should also be aware of the user facility reporting requirement of 
the Safe Medical Device Act of 1990.  A user may be required to submit a
report to FDA if a medical device causes or contributes to a death.  In
addition, the user may be required to report to the manufacturer any serious 
injury or illness involving the device.  For information on user facility
reporting requirements or to determine if they apply to your operation,
contact Bryan Benesch, FDA, at (301) 427-1144.

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The following information, although no specific request nor requirement is
intended, would be helpful to NRC in evaluating the cost of complying with
this Bulletin:

(1)   The licensee staff's time and costs to comply with the requests in this

(2)   The licensee staff's time and costs to prepare the requested report and
      documentation; and

(3)   An estimate of the additional long-term costs that will be incurred in
      the future as a result of implementing commitments. 

If you have any questions about this matter, please contact the technical
contact listed below or the appropriate NRC Regional Office.

                                              ORIGINAL SIGNED BY

                                          Richard E. Cunningham, Director
                                          Division of Industrial and 
                                             Medical Nuclear Safety
                                          Office of Nuclear Material Safety 
                                             and Safeguards

Technical contact:  Robert L. Ayres, IMAB

1.  List of Recently Issued NMSS Bulletins
2.  List of Recently Issued NRC Bulletins



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