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 J NRC/NMSS/IMNS
To:
References
IN-94-039, NUDOCS 9405240145
Download: ML031060531 (9)

IUNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDSWASHINGTON, D.C. 20555May 31, 1994NRC INFORMATION NOTICE 94-39: IDENTIFIED PROBLEMS IN GAMMA STEREOTACTICRADIOSURGERY

Addressees

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

Purpose

NRC is issuing this information notice to alert addressees to problemsidentified in gamma stereotactic radiosurgery. It is expected that recipientswill review this information for applicability to their facilities andconsider actions, as appropriate. However, suggestions contained in thisinformation notice are not new NRC requirements; therefore, no specificactions nor written response are required.

Description of Circumstances

NRC has become aware of the following incidents and areas of concern in gammastereotactic radiosurgery:1) An incident involving the failure of the treatment timer to activateafter collimator alignment;2) Symmetrical primary beams of radiation exiting the stereotactic unitwhen the shielding door was opened in the treatment mode;3) An incident involving inadvertently inverting film of the treatmentsite for input into the treatment planning system and the subsequentoverriding of the detection of the error by the treatment planningsystem; and4) A published study revealing the frequency of generating anddetecting human error in setting stereotactic coordinates forradiosurgery.Incident 1. A licensee started patient treatment and noticed that the timeractivation light and the timer did not come on when the patient was positionedFlickinger, J.C., Lunsford, L.D., and Kondziolka, D., "PotentialHuman 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 9005,31'11 IN 94-39May 31, 1994 in the treatment radiation field. The licensee reported that it used backuptiming by stopwatch to complete the exposure, when the patient couch did noteject as expected. After completion of the treatment, the patient was removedwithout incident. The equipment was inspected and a switch that should havetriggered the two timers and an indication of "Treatment Underway" was foundto be loose. After the switch was secured and adjusted, the unit operatedproperly. The licensee concluded that this type of malfunction might occur atany time when there is a gross misalignment of microswitches, broken wire, orother disconnect between the switch and the timer mechanism.Incident 2. In March 1992, an Agreement State notified NRC that a hospitalphysicist detected two symmetrical beams of radiation exiting the stereotacticradiosurgery unit when the shielding door was open in the treatment mode. Thesame problem was identified at two other facilities. The Agreement Staterequired the manufacturer of the unit to evaluate the problem and takecorrective action. The manufacturer subsequently informed the Agreement Statethat two channels had allowed radiation to exit the unit unshielded. As acorrective action, the manufacturer designed and completed a retrofit of allexisting units with a wall extension, to shield the two channels, by October1992.Incident 3. An arteriovenous malformation on the left side of the brain wasbeing treated. An x-ray film was inverted before input into the treatmentplanning system. The treatment planning system initially rejected the image,recognizing it only as an older orientation system. Eventually, theneurosurgeon and physicist overrode the program and instructed the program toaccept the reversed image. They then proceeded to generate treatment plansfor two separate targets. After completing the first of two 8-minute shotsfor the first treatment plan and initiating the second, the physicist noticedthat the X coordinates of the target points for the second treatment planindicated a right-sided target, not left-sided as had been desired. Heimmediately terminated the second shot, with approximately 5X minutesremaining. After dose reconstruction, it was determined that the Y and Zcoordinates were correct; however, the X offset resulted in a target miss of16 mm.Journal Article. The journal article describes the determination of the errorrate in setting 396 isocenter treatments for 101 patients. Of the first 200,the spontaneous errors in setting the stereotactic coordinates >0.25 mm weredetermined to be 12 percent. The errors were attributed to visual limitation,transposition of coordinates, and wrong isocenter set-up. The second part ofthe study determined the detection efficiency of observers in detecting 25intentionally introduced errors in isocenter coordinate settings. The errordetection efficiency of observers was 60.0 percent for 0.25 mm, 95.0 percentfor 0.50 mm, 94.4 percent for 1 to 20 mm, and 83.5 percent for all errors.DiscussionThe treatment-timer failure (Incident 1, above) highlights the importance ofproper maintenance and housekeeping of the stereotactic treatment unit, andhaving a backup timing system to verify treatment time. If a check of thesystem had been performed before the treatment, the loose switch might havebeen detected and the incident avoided. If the treatment facility had not had IN 94-39May 31, 1994 an auxiliary treatment timing system, the stopwatch, there might have beendifficulty in determining that the prescribed dose had been delivered.However, according to the manufacturer, in the described condition, thestereotactic treatment unit is equipped with a safety circuit that terminatesthe treatment within approximately 2 minutes after the "Treatment Start"button is pushed, and had the physicians not decided to interrupt thetreatment, the couch would have been ejected and the treatment interruptedautomatically, within a few seconds, thus limiting the total dose.The radiation leakage (Incident 2, above) is of concern because if a staffmember had needed to attend to a patient during-treatment, he/she might havebeen exposed to this unshielded primary beam of radiation. The potentialexisted for exceeding occupational dose limits. Acceptance testing ofteletherapy units and gamma stereotactic radiosurgery units should alwaysinclude health physics surveys, to ensure the safety of staff members duringroutine and non-routine uses. In this instance, the shielding retrofit by themanufacturer should eliminate this particular area of concern.The use of the inverted image (Incident 3, above) demonstrates to theimportance of understanding the software package used in treatment planning,and not bypassing warning signals without understanding or addressing thewarning or its cause. Uninformed use of treatment planning software, withoutindependent verification (e.g., hand calculation, double check by a secondindividual, etc.), may lead to serious consequences. Fortunately, in thiscase, the licensee reported that the dose was delivered to areas of the brain"... with extremely high tolerance for deficit, ar! that the dose deliveredwas well below the dose-volume threshold for inducing any neurologicaldamage"; however, this may not be the case for future incidents of thisnature.The journal article (Item 4, above) points out the importance of verificationof coordinate setting by a person other than the one setting the coordinates.According to the study, an individual will set the coordinates incorrectly 12percent of the time. If the coordinates are checked by an observer, theerrors will be detected on average 83.5 percent of the time, reducing thenumber of undetected errors to approximately 2 percent.Licensees are reminded that 10 C.F.R §35.32 requires, in part, theestablishment of a written Quality Management Program (QMP), to meet fivespecific objectives for gamma stereotactic radiosurgery:1) Prior to administration, a written directive** is prepared;2) That, prior to each administration, the patient's identity isverified by more than one method as the individual named in thewritten directive;For gamma stereotactic radiosurgery, a written directive means anorder in writing for a specific patient, dated and signed by anauthorized user prior to the administration of radiation, containingthe target coordinates, collimator size, plug pattern, and totaldose. 10 C.F.R. §35.2(3).

IN 94-39May 31, 1994 ) That final plans of treatment and related calculations are inaccordance with the respective written directives;4) That each administration is in accordance with the writtendirective; and5) That any unintended deviation from the written directive isidentified and evaluated, and appropriate action is taken.Licensees should review their QMP to ensure that policies and procedures areadequate to provide, as required by 10 C.F.R. §35.32(a), high confidence thatthe radiation from the byproduct material will be administered as directed bythe authorized user.This information notice requires no specific action nor written response. Ifyou have questions about the information in this notice, please contact thetechnical contact listed below, or the appropriate regional office.Carl J. Paperiel , DirectoDivision of Industrial andMedical Nuclear SafetyOffice of Nuclear Material Safetyand SafeguardsTechnical contact: James Smith, NMSS(301) 415-7904

Attachments:

1. List of Recently Issued NMSS Information Notices2. List of Recently Issued NRC Information Notices Attachment 1IN 94-39May 31, 1994 LIST OF RECENTLY ISSUEDNMSS INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to94-3794-35Misadministration Causedby a Bent InterstitialNeedle during Brachy-therapy ProcedureNIOSH Respirator UserNotices, "InadvertentSeparation of the Mask-Mounted Regulator (MMR)from the Facepiece on theMine Safety Appliances (MSA)Company MMR Self-ContainedBreathing Apparatus (SCBA)and Status Update"Guidance to Hazardous,Radioactive and MixedWaste Generators on theElements of A WasteMinimization Program05/27/9405/16/9403/25/94All U.S. Nuclear RegulatoryCommission Medical Licenseesauthorized to use brachy-therapy sources in high-,medium-, and pulsed-dose-rate remote afterloaders.All holders of OLs or CPsfor nuclear power reactors,and all licensed fuelfacilities.All NRC licensees.94-2394-21Regulatory Requirementswhen No Operations arebeing Performed03/18/94All fuel cycle andlicensees.materials94-17Strontium-90 Eye Appli-cators: Submission ofQuality Management Plan(QMP), Calibration, andUseRecent Incidents Resultingin Offsite Contamination03/11/9403/03/94All U.S. Nuclear RegulatoryCommission Medical UseLicensees.All U.S. Nuclear RegulatoryCommission material and fuelcycle licensees.94-16 Attachment 2IN 94-39May 31, 1994 LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to94-3894-3794-36Results of a Special NRCInspection at DresdenNuclear Power StationUnit 1 Following a Ruptureof Service Water InsideContainmentMisadministration Causedby a Bent InterstitialNeedle during Brachy-therapy ProcedureUndetected Accumulationof Gas in ReactorCoolant SystemSwitchyard Problems thatContribute to Loss ofOffsite PowerNIOSH Respirator UserNotices, "InadvertentSeparation of the Mask-Mounted Regulator (MMR)from the Facepiece on theMine Safety Appliances (MSA)Company MMR Self-ContainedBreathing Apparatus (SCBA)and Status Update"Thermo-Lag 330-660Flexi-Blanket AmpacityDerating Concerns05/27/9405/27/9405/24/9405/19/9405/16/9405/13/94All holders of OLs or CPsfor NPRs and all fuel cycleand materials licenseesauthorized to possess spentfuel.All U.S. Nuclear RegulatoryCommission Medical Licenseesauthorized to use brachy-therapy sources in high-,medium-, and pulsed-dose-rate remote afterloaders.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors,and all licensed fuelfacilities.All holders of OLs or CPsfor nuclear power reactors.91-81,Supp. 194-3594-34OL = Operating LicenseCP = Construction Permit IN 94-39May 31, 1994 ) That final plans of treatment and related calculations are inaccordance with the respective written directives;4) That each administration is in accordance with the writtendirective; and5) That any unintended deviation from the written directive isidentified and evaluated, and appropriate action is taken.Licensees should review their QMP to ensure that policies and procedures areadequate to provide, as required by 10 C.F.R. §35.32(a), high confidence thatthe radiation from the byproduct material will be administered as directed bythe authorized user.This information notice requires no specific action nor written response. Ifyou have questions about the information in this notice, please contact thetechnical contact listed below, or the appropriate regional office.Carl J. Paperiello, DirectorDivision of Industrial andMedical Nuclear SafetyOffice of Nuclear Material Safetyand SafeguardsTechnical contact:James Smith, NMSS(301) 415-7904

Attachments:

1. List of Recently Issued NMSS Information Notices2. List of Recently Issued NRC Information NoticesCloses IMAB-1650

• See previous concurrenceOF IMAB I IMAB I C IMAB I E Tech Ed I IMOBNAME JASmith* LWCamper* JEGlenn* Ekraus* FCCombs*DATE 03/18/94 03/18/94 03/31/94 04/06/94 04/06/94OFC OGC DD/IMNS [ ILI I E f INAME STreby* WBrach* CPaperiello*l DATE jo05/12/94 05/19/94 1 05/20/94 1 IDOC NAME:94-39. INOfficial Record Copy NMSS HEADQUARTERS DAILY REPORT FORMOFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDSMay 31, 1994INFORMATION NOTICE NO. 94- 39,"Identified Problems In Gamma StereotacticRadiosuraervywas issued on May 31. 1994 .(date)The technical contact is James A. Smith.Jr. O , ext. 415-7904Summary: The NRC has identified the following areas of concern in gammastereotactic radiosurgery: a published study of the frequency ofgenerating and detecting human error in setting stereotacticcoordinates for radiosurgery; symmetrical primary beams ofradiation exiting the stereotactic unit when the shielding doorwas opened in the treatment mode; an incident inadvertentinverting of film of the treatment site for input into thetreatment planning system and the subsequent overriding of thedetection of the error by the treatment planning system; and anincident involving the failure of the treatment timer to activateafter collimator alignmen V.> <_IN 94-May , 1994 ) That final plans of treatment and related calculations are inaccordance with the respective written directives;4) That each administration is in accordance with the writtendirective; and5) That any unintended deviation from the written directive isidentified and evaluated, and appropriate action is taken.Licensees should review their QMP to ensure that policies and procedures areadequate to provide, as required by 10 C.F.R. §35.32(a), high confidence thatthe radiation from the byproduct material will be administered as directed bythe authorized user.This information notice requires no specific action nor written response. Ifyou have questions about the information in this notice, please contact thetechnical contact listed below, or the appropriate regional office.Carl J. Paperiello, DirectorDivision of Industrial andMedical Nuclear SafetyOffice of Nuclear Material Safetyand SafeguardsTechnical contact:James Smith, NMSS(301) 415-7904

Attachments:

1. List of Recently Issued NMSS Information Notices2. List of Recently Issued NRC Information NoticesCloses IMAB-1650

• See Drevious concurrenceiOFC IMAB C.,o 14AB lC IMAB lE Tech Ed lIMOB lNAME JASmith S LWCamper* JEGlenn* Ekraus* FCCombs*DATE ' /I %/ e03/18/94 03/31/94 04/06/94 04/06/94lOFC A v6 GIL DD/IMNS J D/IMNSNAM STreb' y ' = CPaperiello _DATE I /f r _C a COYLKEL COYER IK ENCLOSUREOfficial Record CopyN -NO COPYG:\IMAB1650