Information Notice 1994-39, Identified Problems in Gamma Stereotactic Radiosurgery

Identified Problems in Gamma Stereotactic Radiosurgery

ML031060531
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	05/31/1994
From:	Paperiello C NRC/NMSS/IMNS
To:
References
IN-94-039, NUDOCS 9405240145
Download: ML031060531 (9)

I

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS

WASHINGTON, D.C. 20555 May 31, 1994 NRC INFORMATION NOTICE 94-39: IDENTIFIED PROBLEMS IN GAMMA STEREOTACTIC

RADIOSURGERY

Addressees

All U.S. Nuclear Regulatory Commission Teletherapy Medical Licensees.

Purpose

NRC is issuing this information notice to alert addressees to problems

identified in gamma stereotactic radiosurgery. 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 are required.

Description of Circumstances

NRC has become aware of the following incidents and areas of concern in gamma

stereotactic radiosurgery:

1) An incident involving the failure of the treatment timer to activate

after collimator alignment;

2) Symmetrical primary beams of radiation exiting the stereotactic unit

when the shielding door was opened in the treatment mode;

3) An incident involving inadvertently inverting film of the treatment

site for input into the treatment planning system and the subsequent

overriding of the detection of the error by the treatment planning

system; and

4) A published study revealing the frequency of generating and

detecting human error in setting stereotactic coordinates for

radiosurgery.

Incident 1. A licensee started patient treatment and noticed that the timer

activation light and the timer did not come on when the patient was positioned

Flickinger, J.C., Lunsford, L.D., and Kondziolka, D., "Potential

Human Error in Setting Stereotactic Coordinates for Radiosurgery:

Implications for Quality Assurance," Int. J. Radiat. Oncol. Biol.

PhYs. 27(2); 397-41;1993. Reprint requests to: John C. Flickinger, M.D., Joint Radiation Oncology Center, 230 Lothrop St., Pittsburgh, PA 15213.

9405240145 PD9 2 E Nofie f-O37 0 9 05,31

'11

IN 94-39 May 31, 1994 in the treatment radiation field. The licensee reported that it used backup

timing by stopwatch to complete the exposure, when the patient couch did not

eject as expected. After completion of the treatment, the patient was removed

without incident. The equipment was inspected and a switch that should have

triggered the two timers and an indication of "Treatment Underway" was found

to be loose. After the switch was secured and adjusted, the unit operated

properly. The licensee concluded that this type of malfunction might occur at

any time when there is a gross misalignment of microswitches, broken wire, or

other disconnect between the switch and the timer mechanism.

Incident 2. In March 1992, an Agreement State notified NRC that a hospital

physicist detected two symmetrical beams of radiation exiting the stereotactic

radiosurgery unit when the shielding door was open in the treatment mode. The

same problem was identified at two other facilities. The Agreement State

required the manufacturer of the unit to evaluate the problem and take

corrective action. The manufacturer subsequently informed the Agreement State

that two channels had allowed radiation to exit the unit unshielded. As a

corrective action, the manufacturer designed and completed a retrofit of all

existing units with a wall extension, to shield the two channels, by October

1992.

Incident 3. An arteriovenous malformation on the left side of the brain was

being treated. An x-ray film was inverted before input into the treatment

planning system. The treatment planning system initially rejected the image, recognizing it only as an older orientation system. Eventually, the

neurosurgeon and physicist overrode the program and instructed the program to

accept the reversed image. They then proceeded to generate treatment plans

for two separate targets. After completing the first of two 8-minute shots

for the first treatment plan and initiating the second, the physicist noticed

that the X coordinates of the target points for the second treatment plan

indicated a right-sided target, not left-sided as had been desired. He

immediately terminated the second shot, with approximately 5X minutes

remaining. After dose reconstruction, it was determined that the Y and Z

coordinates were correct; however, the X offset resulted in a target miss of

16 mm.

Journal Article. The journal article describes the determination of the error

rate in setting 396 isocenter treatments for 101 patients. Of the first 200,

the spontaneous errors in setting the stereotactic coordinates >0.25 mm were

determined to be 12 percent. The errors were attributed to visual limitation, transposition of coordinates, and wrong isocenter set-up. The second part of

the study determined the detection efficiency of observers in detecting 25 intentionally introduced errors in isocenter coordinate settings. The error

detection efficiency of observers was 60.0 percent for 0.25 mm, 95.0 percent

for 0.50 mm, 94.4 percent for 1 to 20 mm, and 83.5 percent for all errors.

Discussion

The treatment-timer failure (Incident 1, above) highlights the importance of

proper maintenance and housekeeping of the stereotactic treatment unit, and

having a backup timing system to verify treatment time. If a check of the

system had been performed before the treatment, the loose switch might have

been detected and the incident avoided. If the treatment facility had not had

IN 94-39 May 31, 1994 an auxiliary treatment timing system, the stopwatch, there might have been

difficulty in determining that the prescribed dose had been delivered.

However, according to the manufacturer, in the described condition, the

stereotactic treatment unit is equipped with a safety circuit that terminates

the treatment within approximately 2 minutes after the "Treatment Start"

button is pushed, and had the physicians not decided to interrupt the

treatment, the couch would have been ejected and the treatment interrupted

automatically, within a few seconds, thus limiting the total dose.

The radiation leakage (Incident 2, above) is of concern because if a staff

member had needed to attend to a patient during-treatment, he/she might have

been exposed to this unshielded primary beam of radiation. The potential

existed for exceeding occupational dose limits. Acceptance testing of

teletherapy units and gamma stereotactic radiosurgery units should always

include health physics surveys, to ensure the safety of staff members during

routine and non-routine uses. In this instance, the shielding retrofit by the

manufacturer should eliminate this particular area of concern.

The use of the inverted image (Incident 3, above) demonstrates to the

importance of understanding the software package used in treatment planning, and not bypassing warning signals without understanding or addressing the

warning or its cause. Uninformed use of treatment planning software, without

independent verification (e.g., hand calculation, double check by a second

individual, etc.), may lead to serious consequences. Fortunately, in this

case, the licensee reported that the dose was delivered to areas of the brain

"... with extremely high tolerance for deficit, ar! that the dose delivered

was well below the dose-volume threshold for inducing any neurological

damage"; however, this may not be the case for future incidents of this

nature.

The journal article (Item 4, above) points out the importance of verification

of coordinate setting by a person other than the one setting the coordinates.

According to the study, an individual will set the coordinates incorrectly 12 percent of the time. If the coordinates are checked by an observer, the

errors will be detected on average 83.5 percent of the time, reducing the

number of undetected errors to approximately 2 percent.

Licensees are reminded that 10 C.F.R §35.32 requires, in part, the

establishment of a written Quality Management Program (QMP), to meet five

specific objectives for gamma stereotactic radiosurgery:

1) Prior to administration, a written directive** is prepared;

2) That, prior to each administration, the patient's identity is

verified by more than one method as the individual named in the

written directive;

For gamma stereotactic radiosurgery, a written directive means an

order in writing for a specific patient, dated and signed by an

authorized user prior to the administration of radiation, containing

the target coordinates, collimator size, plug pattern, and total

dose. 10 C.F.R. §35.2(3).

IN 94-39 May 31, 1994 3) That final plans of treatment and related calculations are in

accordance with the respective written directives;

4) That each administration is in accordance with the written

directive; and

5) That any unintended deviation from the written directive is

identified and evaluated, and appropriate action is taken.

Licensees should review their QMP to ensure that policies and procedures are

adequate to provide, as required by 10 C.F.R. §35.32(a), high confidence that

the radiation from the byproduct material will be administered as directed by

the authorized user.

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.

Carl J. Paperiel , Directo

Division of Industrial and

Medical Nuclear Safety

Office of Nuclear Material Safety

and Safeguards

Technical contact: James Smith, NMSS

(301) 415-7904 Attachments:

1. List of Recently Issued NMSS Information Notices

2. List of Recently Issued NRC Information Notices

Attachment 1 IN 94-39 May 31, 1994 LIST OF RECENTLY ISSUED

NMSS INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

94-37 Misadministration Caused 05/27/94 All U.S. Nuclear Regulatory

by a Bent Interstitial Commission Medical Licensees

Needle during Brachy- authorized to use brachy- therapy Procedure therapy sources in high-,

medium-, and pulsed-dose- rate remote afterloaders.

94-35 NIOSH Respirator User 05/16/94 All holders of OLs or CPs

Notices, "Inadvertent for nuclear power reactors, Separation of the Mask- and all licensed fuel

Mounted Regulator (MMR) facilities.

from the Facepiece on the

Mine Safety Appliances (MSA)

Company MMR Self-Contained

Breathing Apparatus (SCBA)

and Status Update"

94-23 Guidance to Hazardous, 03/25/94 All NRC licensees.

Radioactive and Mixed

Waste Generators on the

Elements of A Waste

Minimization Program

94-21 Regulatory Requirements 03/18/94 All fuel cycle and materials

when No Operations are licensees.

being Performed

94-17 Strontium-90 Eye Appli- 03/11/94 All U.S. Nuclear Regulatory

cators: Submission of Commission Medical Use

Quality Management Plan Licensees.

(QMP), Calibration, and

Use

94-16 Recent Incidents Resulting 03/03/94 All U.S. Nuclear Regulatory

in Offsite Contamination Commission material and fuel

cycle licensees.

Attachment 2 IN 94-39 May 31, 1994 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

94-38 Results of a Special NRC 05/27/94 All holders of OLs or CPs

Inspection at Dresden for NPRs and all fuel cycle

Nuclear Power Station and materials licensees

Unit 1 Following a Rupture authorized to possess spent

of Service Water Inside fuel.

Containment

94-37 Misadministration Caused 05/27/94 All U.S. Nuclear Regulatory

by a Bent Interstitial Commission Medical Licensees

Needle during Brachy- authorized to use brachy- therapy Procedure therapy sources in high-,

medium-, and pulsed-dose- rate remote afterloaders.

94-36 Undetected Accumulation 05/24/94 All holders of OLs or CPs

of Gas in Reactor for nuclear power reactors.

Coolant System

91-81, Switchyard Problems that 05/19/94 All holders of OLs or CPs

Supp. 1 Contribute to Loss of for nuclear power reactors.

Offsite Power

94-35 NIOSH Respirator User 05/16/94 All holders of OLs or CPs

Notices, "Inadvertent for nuclear power reactors, Separation of the Mask- and all licensed fuel

Mounted Regulator (MMR) facilities.

from the Facepiece on the

Mine Safety Appliances (MSA)

Company MMR Self-Contained

Breathing Apparatus (SCBA)

and Status Update"

94-34 Thermo-Lag 330-660 05/13/94 All holders of OLs or CPs

Flexi-Blanket Ampacity for nuclear power reactors.

Derating Concerns

OL = Operating License

CP = Construction Permit

IN 94-39 May 31, 1994 3) That final plans of treatment and related calculations are in

accordance with the respective written directives;

4) That each administration is in accordance with the written

directive; and

5) That any unintended deviation from the written directive is

identified and evaluated, and appropriate action is taken.

Licensees should review their QMP to ensure that policies and procedures are

adequate to provide, as required by 10 C.F.R. §35.32(a), high confidence that

the radiation from the byproduct material will be administered as directed by

the authorized user.

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.

Carl J. Paperiello, Director

Division of Industrial and

Medical Nuclear Safety

Office of Nuclear Material Safety

and Safeguards

Technical contact: James Smith, NMSS

(301) 415-7904 Attachments:

1. List of Recently Issued NMSS Information Notices

2. List of Recently Issued NRC Information Notices

Closes IMAB-1650

• See previous concurrence

OF IMAB I IMAB I C IMAB I E Tech Ed I IMOB

NAME JASmith* LWCamper* JEGlenn* Ekraus* FCCombs*

DATE 03/18/94 03/18/94 03/31/94 04/06/94 04/06/94 OFC OGC DD/IMNS [ ILI I IE f

NAME STreby* WBrach* CPaperiello*

l DATE jo05/12/94 DOC NAME: 94-39. IN

05/19/94 1 05/20/94 1 I

Official Record Copy

NMSS HEADQUARTERS DAILY REPORT FORM

OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS

May 31, 1994 INFORMATION NOTICE NO. 94- 39,"Identified Problems In Gamma Stereotactic

Radiosuraervy

was issued on May 31. 1994 .

(date)

The technical contact is James A. Smith.Jr. O , ext. 415-7904 Summary: The NRC has identified the following areas of concern in gamma

stereotactic radiosurgery: a published study of the frequency of

generating and detecting human error in setting stereotactic

coordinates for radiosurgery; symmetrical primary beams of

radiation exiting the stereotactic unit when the shielding door

was opened in the treatment mode; an incident inadvertent

inverting of film of the treatment site for input into the

treatment planning system and the subsequent overriding of the

detection of the error by the treatment planning system; and an

incident involving the failure of the treatment timer to activate

after collimator alignment.

<_IN

V.> 94- May , 1994 3) That final plans of treatment and related calculations are in

accordance with the respective written directives;

4) That each administration is in accordance with the written

directive; and

5) That any unintended deviation from the written directive is

identified and evaluated, and appropriate action is taken.

Licensees should review their QMP to ensure that policies and procedures are

adequate to provide, as required by 10 C.F.R. §35.32(a), high confidence that

the radiation from the byproduct material will be administered as directed by

the authorized user.

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.

Carl J. Paperiello, Director

Division of Industrial and

Medical Nuclear Safety

Office of Nuclear Material Safety

and Safeguards

Technical contact: James Smith, NMSS

(301) 415-7904 Attachments:

1. List of Recently Issued NMSS Information Notices

2. List of Recently Issued NRC Information Notices

Closes IMAB-1650

• See Drevious concurrence

iOFC IMAB C.,o 14AB lC IMAB lE Tech Ed lIMOB l

NAME JASmith SLWCamper* JEGlenn* Ekraus* FCCombs*

DATE '/I%/e03/18/94 03/31/94 04/06/94 04/06/94 lOFC A GILv6 DD/IMNS J D/IMNS

NAM STreb'y ' = CPaperiello _

DATE I /f r _

C a COYLK EL COYER IKENCLOSURE N - NO COPY

Official Record Copy G:\IMAB1650