Information Notice 2005-27, Low-Dose-Rate Manual Brachytherapy Equipment-Related Medical Events
ML052780358 | |
Person / Time | |
---|---|
Issue date: | 10/07/2005 |
From: | Chris Miller NRC/NMSS/IMNS |
To: | |
Zelac R | |
Shared Package | |
ML052780535 | List: |
References | |
IN-05-027 | |
Download: ML052780358 (9) | |
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
WASHINGTON, D.C. 20555-0001 October 7, 2005 NRC INFORMATION NOTICE 2005-27: LOW-DOSE-RATE MANUAL BRACHYTHERAPY--
EQUIPMENT-RELATED MEDICAL EVENTS
ADDRESSEES
All medical licensees.
PURPOSE
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice (IN) to inform
addressees of recently reported medical events that occurred during an NRC licensees
implementation of low-dose-rate (LDR) manual brachytherapy procedures. It is expected that
recipients will review this information for applicability to their licensed operations and consider
actions, as appropriate, to avoid similar problems. However, the information contained in this
IN does not constitute new NRC requirements; therefore, no specific action nor written
response is required.
DESCRIPTION OF CIRCUMSTANCES
On March 28, 2005, an NRC licensee reported to NRC its identification of two medical events
involving radiation doses to unintended treatment sites of two patients. The licensee had
administered LDR manual brachytherapy treatments to the patients in February and March
2004 and, during a subsequent review, licensee staff determined that the treatments had
resulted in medical events, as defined in NRCs regulations. During a special NRC inspection
conducted on March 30, 2005, to review the circumstances of the two medical events reported
by the licensee, the inspector identified three additional patients who had treatments similar to
those that resulted in the reported medical events. One of those additional patients exhibited
observable side effects, as did the two patients involved in the medical events reported by the
licensee. As a result, NRC upgraded the special inspection to an Augmented Inspection Team
(AIT) on March 31, 2005. The purpose of the AIT was to examine the conditions and
circumstances surrounding the medical events to determine the probable causes and
contributing factors of the events.
The AIT concluded that five LDR manual brachytherapy treatments had resulted in medical
events, as defined in Title 10 of the Code of Federal Regulations (CFR) Part 35. Three of the
patients developed skin lesions on the upper thighs from radiation doses to the skin of the
upper thighs, an unintended treatment site. The nature of the lesions indicated that the doses
were greater than 1100 centigray (cGy) (1100 rads). The other two patients did not exhibit any
unintended radiation effects. Therefore, those two patients received unintended doses to the
thighs that were below the threshold for observable radiation effects. The AIT also determined
that the root cause of these medical events was the licensee staff use of radioactive sources
with smaller diameters than that specified in the instructions distributed with the brachytherapy
applicator employed in all five cases. This error allowed the sources to move from their
intended position within the applicator to a position that resulted in the unintended doses to the
skin of the five patients.
The applicator involved in the five medical events was a Mick Radio-Nuclear Instruments, Inc.
Wang Front-Loading Vaginal Applicator, Model 8524 (applicator), intended for use with
cesium-137 sources, to treat patients. See the attached diagram of the Wang applicator. The
instructions provided with the applicator specified the use of sources manufactured by the 3M
Company (3M), and the applicator was marked with the appropriate source dimensions.
The applicator design allowed the sources to be inserted into the applicator after the applicator
had been positioned in the patient for treatment (i.e., afterloaded), thereby reducing the
radiation dose to brachytherapy staff. After the applicator was positioned within the patient, one
of the sources was placed into a hinged insert, referred to as a bucket, and subsequently
positioned within the applicator, perpendicular to two sources to be positioned in the tandem
portion of the applicator. The tandem sources were loaded into a closable flexible carrier tube, and a coil spring was inserted into the tube, to hold the sources in position. Once the loaded
flexible carrier tube was closed, the tube was placed into the applicator.
During each of the first five brachytherapy treatments performed by the licensee with the Wang
applicator, that resulted in medical events, licensee staff selected G.E. Healthcare (formerly
known as Amersham; hereafter referred to as Amersham) sources for use in the tandem
portion of the applicator. The Amersham sources were different in a critical dimension from the
3M sources specified in the instructions - they were too small in diameter, being 2.6 millimeter
(mm) (0.10 inch) in diameter, when 3.1 mm (0.12 inch) diameter sources were specified. As a
result, the tandem sources slid down to the opposite end of the applicators flexible carrier tube
whenever the applicator was tilted more than 20 degrees off-level (i.e., the tandem sources
moved out of their intended position whenever a patient moved more than 20 degrees off-level
(e.g., sat up) during treatment), resulting in irradiation of the skin on the patients thighs. The
Amersham sources moved through the center of the applicators carrier tube spring because
the diameter of the sources was smaller than the inner diameter of the coil spring.
The licensee became aware of the error in April 2004, after the authorized user observed
effects during examinations of the three patients who exhibited skin injury. The authorized user
requested that licensee staff investigate the possible cause of the injuries. During this
investigation, licensee staff reviewed the instructions that came with the applicator, noticed
that the instructions specified the use of 3M sources, recognized that the sources that had been
used were Amersham sources, not 3M sources, and discovered the mobility of Amersham
sources when used in the applicators tandem source holder.
In April 2004, immediately after the licensee identified that the Amersham sources could
change position in the Wang applicators tandem source carrier tube during brachytherapy
treatments, the licensee initiated actions to prevent similar unintended patient exposures. The licensee modified the applicator by using different hardware to keep the radioactive sources in
proper position during brachytherapy treatments. The licensees modification of the applicator
was effective.1 However, the licensee misinterpreted the medical event reporting requirements
in 10 CFR 35.3045(a)(3) and failed to promptly identify, in April 2004, that multiple medical
events had occurred. Reporting of medical events (2) to NRC was delayed until March 2005, when, following patient reexaminations, the licensee determined that treatment side effects for
two patients were more severe than previously observed.
DISCUSSION
NRC staff reviewed the instructions associated with use of the Wang applicator and identified
several issues of generic concern that staff believes may result in improper use of the device.
For example:
- Instructions explaining the use of alternate sources were not clear. Portions of the
instructions provided with the applicator indicated that only 3M sources should be used
with the applicator. However, other portions of the instructions indicated that the
tandem portion of the applicator may be loaded with sources manufactured by other
suppliers, and it referenced an attachment with source comparisons. The attachment
was not clear regarding what other sources could be used (e.g., it did not indicate the
source manufacturers names or the technical limitations on source physical
dimensions).
- Instructions explaining the proper configuration of sources were not clear. The
instructions indicated that the applicator used three sources in a T configuration (e.g.,
one in the bucket and two in the tandem portion of the applicator). However, another
section stated that up to four sources could be used in the tandem portion of the
applicator.
- Instructions did not clearly alert the user to proper action that must be taken if the spring
in the tandem portion of the applicator required shortening. The distal end of the
applicator coil spring was designed with an inward bend, to prevent source movement
down the center of the spring. The instructions stated that the applicator spring could
be shortened. This would be necessary if more than two sources were used in the
tandem portion of the applicator. The instructions did not provide a warning to the user
not to cut the distal end of the spring with the inward bend, if shortening of the spring
was necessary. Such an action could result in source movement down the center of the
spring.
The licensee had not used more than two sources in the tandem portion of the applicator for
any of the five similar brachytherapy treatments completed. Therefore, the licensee did not cut
the applicator spring. However, the spring supplied with the licensees applicator did not
include the inward bend at the distal end, which increased the potential for source movement
under certain circumstances. The Amersham sources could, and did, for the five patients
involved in
__________
1 Such a user modification is not regulated by the Food and Drug Administration (FDA). medical events, move down the center of the spring to the opposite end of the tandem portion
of the applicator when the patients undergoing treatment raised up from horizontal positions.
NRC referred the generic-concern issues of the applicator instructions and this licensees
experience with the applicator spring to the FDA for its review and evaluation. Presently, FDAs
review and evaluation of these issues is in progress and has not been completed.
The medical events involved errors in selection of ancillary equipment--sealed radioactive
sources--required for use of the afterloader applicator employed in the treatments, resulting in
failure of the sealed sources to remain in their intended positions throughout the specified
treatment times. Licensees performing LDR manual brachytherapy procedures are expected to
review this IN and:
- Assure that radioactive sources and any other ancillary devices to be used with an LDR
manual brachytherapy applicator for a therapeutic procedure are designed for use with, or are known to be compatible with, the LDR applicator to be used during
the procedure;
- Assure that all LDR manual brachytherapy applicator users are familiar with the
operating procedures and applicable usage restrictions of all equipment to be employed
in a therapeutic procedure, before actual use of such devices, associated radioactive
sources, and any other ancillary equipment;
- Encourage device and equipment users to review all vendors pertinent documentation
and clarify any concerns with the vendors, regarding particular devices, sources, or
equipment, before the devices, sources, or equipment are used for patient treatments.
Licensees are expected to clarify any uncertainties, discrepancies, or potential errors in
usage directions provided in vendor-supplied documentation and/or through verbal
discussion with a vendor or on-site vendor representative before use of the device(s),
sources, or equipment; and
- Promptly report: 1) any and all medical events, to NRC; and 2) all equipment
malfunctions or problems, to the vendors and, if required, to the licensing authorities.
CONTACT
S
This information notice does not require any specific action or written response. Please direct
any questions about this matter to the technical contact below, or the appropriate
regional office.
/RA/ Patricia K. Holahan, for
Charles L. Miller, Director
Division of Industrial and
Medical Nuclear Safety
Office of Nuclear Material Safety
and Safeguards
Technical Contact:
Ronald E. Zelac, Ph.D., NMSS
(301) 415-7635 E-mail: rez@nrc.gov
Attachments: 1. Diagram of Wang Applicator
2. List of Recently Issued NMSS Generic Communications
CONTACT
S
This information notice does not require any specific action or written response. Please direct
any questions about this matter to the technical contact below, or the appropriate
regional office.
/RA/Patricia K. Holahan, for
Charles L. Miller, Director
Division of Industrial and
Medical Nuclear Safety
Office of Nuclear Material Safety
and Safeguards
Technical Contact:
Ronald E. Zelac, Ph.D., NMSS
(301) 415-7635 E-mail: rez@nrc.gov
Attachments: 1. Diagram of Wang Applicator
2. List of Recently Issued NMSS Generic Communications
ML052780535 OFFIC MSIB MSIB Tech. Ed. IMNS MSIB IMNS
E:
NAME: RZelac LChang EKraus ICabrera TEssig CMiller/PHolahan
DATE: 7/13 /05 7 /13 /05 7 /12 /05 7 /20 /05 8 /10/05 9/27/05/10/06/05 OFFICIAL RECORD COPY
Attachment 2 Recently Issued NMSS Generic Communications
Date GC No. Subject
Addressees
2/11/05 BL-05-01 Material Control and All holders of operating licenses
Accounting at Reactors and for nuclear power reactors, Wet Spent Fuel Storage decommissioning nuclear power
Facilities reactor sites storing spent fuel in
a pool, and wet spent fuel storage
sites.
8/25/05 RIS-05-18 Guidance for Establishing All licensees, applicants for
and Maintaining a Safety licenses, holders of certificates of
Conscious Work compliance, and their contractors
Environment subject to NRC authority
8/10/05 RIS-05-16 Issuance of NRC All licensees and certificate
Management Directive 8.17, holders.
Licensee Complaints
Against NRC Employees
8/3/05 RIS-05-15 Reporting Requirements for All material licensees possessing
Damaged Industrial industrial radiographic equipment, Radiographic Equipment regulated under 10 CFR Part 34.
7/13/05 RIS-05-13 NRC Incident Response and All licensees and certificate
the National Response Plan holders.
7/11/05 RIS-05-12 Transportation of Licensees authorized to possess
Radioactive Material radioactive material that equals or
Quantities of Concern NRC exceeds the threshold values in
Threat Advisory and the Additional Security Measures
Protective Measures System (ASM) for transportation of
Radioactive Material Quantities of
Concern (RAMQC) under their 10
CFR Part 30, 32, 50, 70, and 71 licenses and Agreement State
licensees similarly authorized to
possess such material in such
quantities under their Agreement
State licenses.
7/11/05 RIS-05-11 Requirements for Power All holders of operating licenses
Reactor Licensees in for nuclear power reactors and
Possession of Devices generally licensed device
Subject to the General vendors.
License Requirements of 10
CFR 31.5 Date GC No. Subject
Addressees
6/10/05 RIS-05-10 Performance-Based All industrial radiography
Approach for Associated licensees and manufacturers and
Equipment in 10 CFR 34.20 distributors of industrial
radiography equipment.
4/18/05 RIS-05-06 Reporting Requirements for All material licensees possessing
Gauges Damaged at portable gauges, regulated under
Temporary Job Sites 10 CFR Part 30.
4/14/05 RIS-05-04 Guidance on the Protection All holders of operating licenses
of Unattended Openings or construction permits for nuclear
that Intersect a Security power reactors, Boundary or Area research and test reactors, decommissioning reactors with
fuel on site, Category 1 fuel cycle
facilities, critical mass facilities, uranium conversion facility, independent spent fuel storage
installations, gaseous diffusion
plants, and certain other material
licensees.
2/28/05 RIS-05-03 10 CFR Part 40 Exemptions All persons possessing aircraft
for Uranium Contained in counterweights containing
Aircraft Counterweights - uranium under the exemption in
Storage and Repair 10 CFR 40.13(c)(5).
7/29/05 IN-05-22 Inadequate Criticality Safety All licensees authorized to
Analysis of Ventilation possess a critical mass of special
Systems at Fuel Cycle nuclear material.
Facilities
6/23/05 IN-05-17 Manual Brachytherapy All medical licensees authorized
Source Jamming to possess a Mick applicator.
5/17/05 IN-05-13 Potential Non-conservative All licensees using the Keno-V.a
Error in Modeling Geometric criticality code module in
Regions in the Standardized Computer Analyses
Keno-v.a Criticality Code for Licensing Evaluation (SCALE)
software developed by Oak Ridge
National Laboratory (ORNL)
5/17/05 IN-05-12 Excessively Large Criticality All licensees authorized to
Safety Limits Fail to Provide possess a critical mass of special
Double Contingency at Fuel nuclear material.
Cycle Facility Date GC No. Subject
Addressees
4/7/05 IN-05-10 Changes to 10 CFR Part 71 All 10 CFR Part 71 licensees and
Packages certificate holders.
4/1/05 IN-05-07 Results of HEMYC Electrical All holders of operating licenses
Raceway Fire Barrier for nuclear power reactors, except
System Full Scale Fire those who have
Testing permanently ceased operations
and have certified that fuel has
been permanently removed
from the reactor vessel, and fuel
facilities licensees.
3/10/05 IN-05-05 Improving Material Control All licensees authorized to
and Accountability Interface possess a critical mass of special
with Criticality Safety nuclear material.
Activities at Fuel
Cycle Facilities
Note: NRC generic communications may be found on the NRC public website at
http://www.nrc.gov, under Electronic Reading Room/Document Collections.