View source for Information Notice 1999-09, Problems Encountered When Manually Editing Treatment Data on the Nucletron Microselectron-HDR (New) Model 105-999

{{Adams
| number = ML031040479
| issue date = 03/24/1999
| title = Problems Encountered When Manually Editing Treatment Data on the Nucletron Microselectron-HDR (New) Model 105-999
| author name = Cool D
| author affiliation = NRC/NMSS/IMNS
| addressee name = 
| addressee affiliation = 
| docket = 05000003, 05000010, 05000029, 05000133, 05000155, 05000171, 05000206, 05000213, 05000219, 05000220, 05000237, 05000244, 05000245, 05000247, 05000249, 05000250, 05000251, 05000254, 05000255, 05000259, 05000260, 05000261, 05000263, 05000265, 05000266, 05000267, 05000269, 05000270, 05000271, 05000272, 05000275, 05000277, 05000278, 05000280, 05000281, 05000282, 05000285, 05000286, 05000287, 05000289, 05000293, 05000295, 05000296, 05000298, 05000301, 05000302, 05000304, 05000305, 05000306, 05000309, 05000311, 05000312, 05000313, 05000315, 05000316, 05000317, 05000318, 05000320, 05000321, 05000322, 05000323, 05000324, 05000325, 05000327, 05000328, 05000329, 05000330, 05000331, 05000333, 05000334, 05000335, 05000336, 05000338, 05000339, 05000341, 05000344, 05000346, 05000348, 05000352, 05000353, 05000354, 05000361, 05000362, 05000364, 05000366, 05000368, 05000369, 05000370, 05000373, 05000374, 05000382, 05000387, 05000388, 05000389, 05000390, 05000391, 05000395, 05000397, 05000400, 05000409, 05000410, 05000412, 05000413, 05000414, 05000416, 05000423, 05000424, 05000425, 05000437, 05000438, 05000439, 05000440, 05000441, 05000443, 05000444, 05000445, 05000446, 05000454, 05000455, 05000456, 05000457, 05000458, 05000461, 05000482, 05000483, 05000498, 05000499, 05000508, 05000528, 05000529, 05000530
| license number = 
| contact person = 
| document report number = IN-99-009, NUDOCS 9903190227
| document type = NRC Information Notice
| page count = 9
}}
{{#Wiki_filter:UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS

WASHINGTON, D.C. 20555 March 24, 1999 NRC INFORMATION NOTICE 99-09: PROBLEMS ENCOUNTERED WHEN MANUALLY

EDITING TREATMENT DATA ON THE NUCLETRON

MICROSELECTRON-HDR (NEW) MODEL 105.999

==Addressees==
:
All medical licensees authorized to conduct high-dose-rate (HDR) remote after loading

brachytherapy treatments.

PurDose:
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to alert

addressees to the potential for patient misadministrations that may result from inadvertent

changes to source step size that can occur when editing dwell time data. It is expected that

recipients will review the information for applicability to their facilities and consider actions, as

appropriate, to address these issues. However, suggestions contained in this information

notice are not new NRC requirements; therefore, no specific action, nor written response, is

required.

==Description of Circumstances==
:
On February 26, 1999, an NRC licensee reported a misadministration that had occurred in the

first fraction of a planned treatment of two fractions of 500 cGy (500 Rads) each for an HDR

vaginal treatment. The sequence of events leading up to this misadministration began with the

licensee encountering difficulty in electronically transferring the treatment plan, for this patient, from its Nucletron treatment planning system to their Nucletron microSelectron HDR treatment

system. After several unsuccessful attempts at electronically transferring the patient's

treatment plan to the treatment system, the licensee elected to manually enter the treatment

plan directly into the treatment system's control station. This was accomplished without

apparent difficulty.

On reviewing the printout of the treatment plan, before beginning treatment, the radiation

oncologist noted that the planned source dwell times were incorrect and instructed that the plan

be revised to the correct dwell times. While making the

required manual entry changes to edit the source dwell times, the keystrokes used in

completing the data entry field changes caused the source step size to change from 2.5 mm to

10 mm. The licensee did not notice this change and the patient, therefore, was treated usin

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IN 99-09 March 24, 1999 the incorrect step size. This resulted in the dose to the intended treatment site being less than

50 percent of the intended dose and considerable unintended dose to tissue distal to the

intended treatment site. The licensee attributes this unintended and unnoticed change in step

size to a software problem with the software used in the Nucletron treatment control station

(TCS). However, had the licensee properly reviewed the complete final treatment plan, immediately before treatment, this misadministration could have been prevented.

Discussion:
A review of the preliminary inspection information related to this misadministration indicated that

there were two software problems that contributed to this event: one with the Nucletron Plato

Treatment Planning system; and, one with the microSelectron-HDR treatment control station.

The documented problem with the treatment planning system was the inability to transfer the

treatment plan to the HDR treatment system from the treatment planning system via disk or

electronically. The microSelectron-HDR treatment system problem was the heretofore

undetected possibility of making unintended and unnoticed changes to the source step size, while editing an unrelated parameter.

The manual data entry into, and subsequent editing of these data on, the Nucletron TCS were

necessitated by the licensee's inability to transfer the original treatment plan for the Nucletron

Plato treatment planning system to the TCS via either the network interface or floppy disk.

Attempts to perform either type of transfer produced a "Error writing to file" with no indication of

what is causing the problem.

A Nucletron service engineer investigated the cause of this transfer problem and found it to

result from an undocumented limitation on the maximum number of combined patient and

applicator points that can be transferred. When a treatment plan has more than 24 combined

patient and applicator points, the treatment planning system refuses to write the treatment plan

data file to either the hard disk or the floppy disk. TCS accesses PLATO's hard disk when a

transfer via the network is required. If such a failure does occur, and the user subsequently

reduces the combined patient and applicator points to a total of 24 or less, then the reduced

data set can be successfully transferred. However, if it is necessary to transfer a treatment plan, to the HDR TCS, that contains a total of more than 24 patient and applicator points, then it will

be necessary to enter either all or part of the treatment plan into the TCS manually.

The sequence of events that led to the erroneous step size change occurred as follows:
         1. The treatment plan that eventually produced the erroneous step size was entered

into the TCS manually because of the previously described inability to transfer it

electronically;
         2. The radiation oncologist discovered that the dwell times of this treatment plan were

in error, when he reviewed the plan;

IN 99-09 March 24, 1999 3. During the subsequent manual editing of the treatment plan on the TCS, to correct

the erroneous source dwell times, the licensee used the "Tab" key twice in an attempt to

move from one dwell time position to the next. This action inadvertently selected the

step size option;
        4. When the previous action had no effect on the selection of the next dwell time

position to be edited, the licensee tried the 'arrow" key twice in an attempt to select the

desired dwell time data. This had the effect of changing the source step size from 2.5 mm to 10 mm;
        5. The licensee did not notice the unintended selection of the step size option and

subsequent change to the value of the step size. This change to the step size would

have also resulted in changing the scale and overall length of the "loading grid ruler"
        above the channel one dwell positions, as well as the "treatment length value" per

channel;
        6. The licensee then used the mouse to select the next dwell time position(s) to be

edited and successfully made the necessary corrections to the source

dwell times.

7. The radiation oncologist reviewed and approved the revised treatment plan without

noticing the altered step size. The patient was subsequently treated using this incorrect

source step size.

The licensee did not discover the error in the step size for the first treatment until one week

later, when it was preparing the treatment plan for the second of the two fractions to be

administered to this patient. When the previous treatment plan was brought up in preparation

for the second treatment, the licensee discovered the increased step size. At this point, the

licensee corrected the erroneous step size and adjusted the written directive, and

corresponding treatment plan, to compensate for the under dosage to the intended treatment

site that occurred in the first fraction.

How did the licensee not notice this step size change? First, in attempting to select the dwell

positions to be edited, by the inappropriate use of the "Tab" and "arrow" keys, the licensee did

not expect this to have any affect on other (unrelated) treatment plan parameters. This

expectation was reinforced by the lack of any cautions or other instructions, in the Nucletron

microSelectron-HDR v1.2X manual, that would indicate otherwise. More importantly, the

licensee expected to see a confirmation message that would have required it to acknowledge

any changes to the treatment plan step size, in accordance with the information on page 4-23 of

the users manual. Secondly, since the licensee did not anticipate that any of the other treatment

plan parameters would change it did not check any parameters other than the source dwell

times on the final printed treatment plan. 7 I

i2 IN 99-09 March 24, 1999 Nucletron has confirmed that this acknowledgment prompt, and corresponding warning

message, only appears when the step size parameter is changed for the first time to a treatment

plan that either: (1) has been electronically transferred from the treatment planning system; or,
(2) has previously had a reference dose entered into TCS. Subsequent changes to the step

size, or changes to the step size in manually entered treatment plans, do not generate the

indicated confirmation box or warning unless you have entered the reference dose on the

previous screen. This behavior is contrary to what would be expected, given the information

provided on page 4-23 of the Nucletron microSelectron HDR users manual, which does not

place any conditions on the expected confirmation prompt from the system. Also, the

descriptions given in the Nucletron TCS manual for the functions of the "Tab" and uarrow* keys

do not include the ability to use these keys for changing treatment plan parameters. Based on

these manual descriptions, the licensee would appear justified in its assumption that no

parameters were inadvertently changed by their inappropriate use of these keys.

This event highlights the importance that, when making changes to treatment plans, licensees

should always be alert to the possibility that other unintended changes can also occur. If such

an unintended change should occur, whether this change were to occur through user error or

system software problems, the potential adverse consequences to the patient remain the same.

Thus, after making any changes to a pre-existing treatment plan, the final treatment plan should

be reviewed for not only for the correctness of the changed parameters but also for its total

overall correctness.

Often device users are the first to discover problems with marketed medical devices. If you

encounter device malfunctions or product problems involving radiation therapy devices or

radiation therapy treatment planning systems, particularly Y2K problems or those which may be

software related, you are strongly encouraged to report such events to MedWatch, the Food

and Drug Administration's (FDA) voluntary reporting program. You may submit voluntary

reports to MedWatch:
*        by phone at 1-800-FDA-1088;
*        by FAX at 1-800-FDA-0178;
*        over the Internet at httP:/ANww.fda.gov/medwatch/; or,
*        by mailing your report to MedWatch, Food and Drug Administration, 5600        Fishers

Lane (HF-2), Rockville, MD 20857.

You are also reminded that under the Safe Medical Devices Act of 1990, user facilities have

specific mandatory reporting time frames and requirements when they become aware that a

medical device may have caused or contributed to a patient death or serious injury/illness.

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IN 99-09 March 24, 1999 Questions concerning FDA's mandatory user facility reporting requirements can be directed to

FDA's Center for Devices and Radiological Health, Office of Surveillance and Biometrics, by

calling (301) 594-2735.

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 E-mail: rxal@nrc.gov

Attachments:
1. List of Recently Issued NMSS Information Notices

2. List of Recently Issued NRC Information Notices

V.

Attachment 1 IN 99-09 March 24, 1999 LIST OF RECENTLY ISSUED

NMSS INFORMATION NOTICES

Information                                          Date of

Notice No.             Subject                        Issuance   Issued to

99-06            1998 Enforcement Sanctions as        3/19/99   All U. S. Nuclear Regulatory

a Result of Deliberate Violations of            Commission licensees.

99-05            Inadvertent Discharge of Carbon      3/8/99    All holders of licenses for nuclear

Dioxide Fire Protection System                  power, research, and test reactor, and Gas Migration                               and fuel cycle facilities

99-04           Unplanned Radiation Exposures         3/8/99    All radiography licensees.

to Radiographers, Resulting from

failures to follow Proper Radiation

Safety Procedures

99-03           Exothermic Reactions Involving        1/29/99   All operating uranium recovery

Dried Uranium Oxide Powder                      facilities that produce oxide

(Yellowcake)                                    powder (U308) (yellowcake)
99-02           Guidance to Users on the              1/21/99   All medical licensees authorized to

Implementation of a New                         conduct brachytherapy

Single-Source Dose-                             treatments.

Calculation Formalism and Revised

Air-Kerma Strength Standard

for lodine-125 Sealed Sources

99-01           Deterioration of High-Efficiency      1/20/99   All holders of licences for nuclear

Particulate Air Filters in a                    power, research and test reactors;
                Pressurized Water Reactor                       and fuel cycle facilities.

Containment Fan Cooler Unit

98-33           NRC Regulations Prohibit              8/28/98   All holders of a Nuclear

Regulatory      Agreements that Restrict or                     Commission license

Discourage an Employee from

Participating in Protected Activities

98-30           Effect of the Year 2000               8/12/98   All material and fuel cycle

Computer Problem on NRC                         licensees and certificate holders

Licensees and Certificate Holders

II

J-     Attachment 2 IN 99-09 March 24, 1999 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information                                          Date of

Notice No.             Subject                       Issuance   Issued to

99-08            Urine Specimen Adulteration         3/24/99    All holders of operating licenses

For nuclear power reactors and

Licensees authorized to possess

Or use formula quantities of

strategic special nuclear material

(SSNM)
99-07            Fire Proctection Preaction          3/22199    All NRC licensees

Preaction Sprinkler System

Deluge Valve Failures and

Potenetial Testing Deficiencies

99-06            1998 Enforcement Sanctions as a     3/19/99    All U.S. Nuclear Regulatory

Result of Deliberate Violation on              Commission licensees

NRC Employee Protection

Requirements

99-05            Inadvertent Discharge of Carbon     3/8/99     All holders of licenses for nuclear

Dioxide Fire Protection System                 power, research, and test reactor, and Gas Migration                              and fuel cycle facilities

99-04            Unplanned Radiation Exposures       3/8/99     All radiography licensees.

to Radiographers, Resulting from

failures to follow Proper Radiation

Safety Procedures

99-03            Exothermic Reactions Involving      1/29/99    All operating uranium recovery

Dried Uranium Oxide Powder                     facilities that produce oxide

(Yellowcake)                                   powder (U308 ) (yellowcake)
99-02            Guidance to Users on the            1/21/99    All medical licensees authorized

Implementation of a New                        to conduct brachytherapy

Single-Source Dose-                            treatments.

Calculation Formalism and Revised

Air-Kerma Strength Standard

for lodine-125 Sealed Sources

OL = Operating License

CP = Construction Permit

IN 99-09 March 24, 1999 Questions concerning FDA's mandatory user facility reporting requirements can be directed to

FDA's Center for Devices and Radiological Health, Office of Surveillance and Biometrics, by

calling (301) 594-2735.

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 E-mail: rxal@nrc.gov

Attachments:
      1. List of Recently Issued NMSS Information Notices

2. List of Recently Issued NRC Information Notices

DOCUMENT NAME: G(l:\):IN99-09.WPD

l l FC MS          llTechED               llMSB              L      lDIMNSTl

NAME            RAyres/I             EKraus(FAx)           LWCamper            DACool

l DATE           03/ 05 /99       j      3/8/99                3/17/99           3/17/99

===OFFICIAL RECORD COPY===

IN 99-XX

March XX. 1999 requirements can be directed to FDA's Center for Devices and Radiological Health, Office of Surveillance and Biometrics, by calling (301) 594-2735.

This information notice requires no specific action nor written response. If you leave

any questions about the information in this notice, please contact the technicat'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 E-mail: rxal @nrc.gov

Attachments:
      1.      List of Recently Issued NMSS Information Notices

2.      List of Recently Issued NRC Information Notices

DOCUMENT NAGE: G(I:\):1N99-XX.WPD

l OFA                                 TechED           J/   MA     1        , D/IS,
  NAME            RAyres/ll             EKraus(FAX)                   r         AC

[DATE            03/05/99                  3/8/99                   99         03/ &/99 OFFICIAL RECORD COPY

!}}

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