UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE
Contents
1. if you are a Multidata customer you should have received notices from the firm about this incident If you have not received the attached communications from Multidata you should contact its Helpdesk at 1 800 225 1130 or helodesk multidata systems com The U S Food and Drug Administration FDA is investigating this incident and NRC is cooperating with its investigation 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 those that may be software related you are strongly encouraged to report such events to MedWatch the FDA s voluntary reporting program You may submit voluntary reports to MedWatch through Phone at 1 800 FDA 1088 j FAX at 1 800 FDA 0178 IN 2001 08 Supp 2 Page 3 of 3 The Internet at http www fda gov medwatch or Mailing your report to MedWatch Food and Drug Administration 5600 Fishers Lane HF 2 Rockville MD 20857 Also note that under the Safe Medical Devices Act of 1990 user facilities must comply with 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 Questions concerning FDA s mandatory user facility reporting requirements can be directed to FDA s Center for Devices and Radiolo2. on the basis that it is not a true polygon has been developed and is currently being tested Once the project is complete Multidata will make this program available to all customers in the form of an easy to install update It is expected that this safeguard program will be compatible with any software version in use Your Response We ask that you confirm receipt of this letter by August 24 2001 Notify Multidata Helpdesk by telephone at 800 225 1130 by facsimile FAX at 314 968 6443 or by E mail at helpdesk multidata systems com If you no longer use the treatment planning system let us know so that you can be removed from the user list If you have any questions concerns or doubt about the proper operation of the treatment planning system please contact us Multidata Systems International Corp AON Mick Conley General and Business Manager Attachment 2 MULTIDATA IN 2001 08 Supp 2 Page 2 of 2 Urgent Notice for Users of Multidata s Treatment Planning Systems Multidata has determined that its treatment planning system will accept blocks that are entered improperly in a manner other than that specified in the user manual When a block is entered improperly the results may differ from those expected by the user In BEV regardless of the direction in which the block is entered or the shape of the block when the block outline crosses itself see Fig 1 left an improper block is created i e not a true polyg
3. 10 2001 Urgent Notice For All Users of Multidata Treatment Planning Systems Dear Customer of Multidata Systems The attached Notice for All Users of Multidata s Treatment Planning Systems is a follow up to the recently distributed Medical Device Safety Alert It explains an improper entry of block shapes and its effect on dose calculation results In short as long as the block outline does not cross itself the dose calculations should correlate with the results obtained by an appropriate method of independent validation For the Multidata Treatment Planning System such methods include hand calculations or calculations using the central axis dose calculation program CHT or the irregular fields utility IRF Multidata shares the concern that an improper data entry sequence was permitted as input Therefore through its Project Safeguard Multidata has identified a data entry sequence that creates a self intersecting shape outline See Fig 1 on the attached sheet as what is not acceptable Digitizing direction and exceeding the limitations on the number of blocks numbers of points per block or the block shape have no unexpected effect on the dose calculation For information about specific limitations as to the number of blocks or points used in a particular plan please refer to the user manual provided with your version of the software A filter program which automatically rejects an improper data entry sequence as an unacceptable outline
4. UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS WASHINGTON D C 20555 0001 November 20 2001 NRC INFORMATION NOTICE 2001 08 SUPPLEMENT 2 UPDATE ON RADIATION THERAPY OVEREXPOSURES IN PANAMA Addressees All medical licensees Purpose The U S Nuclear Regulatory Commission NRC is issuing this supplement to information notice IN 2001 08 to provide additional information related to the radiation therapy overexposures that recently occurred in Panama All persons in your institution who are involved with radiation therapy should review this notice It is expected that recipients will review this information for applicability to their facilities and consider actions as appropriate to avoid similar problems However suggestions contained in this IN are not new NRC requirements therefore no specific action nor written response is required Description of Circumstances IN 2001 08 dated June 1 2001 and Supplement 1 dated June 6 2001 describe an incident in Panama involving radiation overexposures of 28 teletherapy patients resulting in multiple deaths The International Atomic Energy Agency IAEA recently published its report entitled Investigation of an Accidental Exposure of Radiotherapy Patients in Panama which concluded that the cause of the radiation overexposures was the way the shielding block data were entered into the computerized treatment planning system The repor
5. ency in Panama when the International Atomic Energy Agency IAEA and the U S Nuclear Regulatory Commission US NRC released reports of an IAEA investigation of multiple radiation overexposures and deaths Two IAEA reports and two US NRC Information Notices IN2001 8 and IN2001 8 Supplement 1 indicate the National Oncology Institute in Panama was using a Theratron 780 C cobalt 60 teletherapy machine and a Multidata Systems computerized treatment planning system to calculate the radiation doses delivered to the patients The reports are available on our website at http www multidata systems com In related reports Panama s Health Minister Fernando Garcia said health officials changed their procedures in administering the radiation treatment in order to get better results and ended up giving the patients more radiation than they should have The incident involved 28 patients who were treated at the center from August 2000 through February 2001 for colon prostate and cervical cancer Eight patients died and five deaths are attributed to excess radiation received during the treatments The eight year old treatment planning system in use at the time RTP version 2 2 has a limitation on the number of shielding blocks that can be used in a treatment plan It was reported the practice at the facility was changed in August 2000 to enter data in such a way as to appear to allow the treatment system to exceed its limitation on shielding blocks even thoug
6. gical Health Office of Surveillance and Biometrics through telephone at 301 594 2735 This IN requires no specific action nor written response If you have any questions about the information in this notice please contact one of the technical contacts 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 Contacts Robert Ayres NUSS Donna Beth Howe NUSS 301 415 5746 301 415 7848 E mail rxa1 nrc gov E mail doh nrc gov Roberto J Torres NUSS 301 415 8112 E mail rjt nrc gov Attachments 1 Medical Device Safety Alert June 22 2001 2 Urgent Notice August 10 2001 3 List of Recently Issued NMSS Information Notices 4 List of Recently Issued NRC Information Notices Attachment 1 IN 2001 08 Supp 2 Page 1 of 2 June 22 2001 URGENT Medical Device Safety Alert Dear U S and International Customers of Multidata Systems This letter informs you of radiation overexposures and deaths associated with Multidata radiation treatment planning software It explains our actions to investigate and follow up on the overexposure incidents and reinforces the need for you to conduct adequate quality assurance Provide this letter to medical physicists radiologists clinical engineers and risk managers at your facility Radiation Overexposures Multidata became aware of a radiological emerg
7. h the user manual for the treatment planning system not only specifies the limit but also recommends that the results be verified by measurement before using Multidata Actions Multidata is in the process of obtaining information on this incident and is collaborating with the various regulatory agencies including the US NRC and the U S Food and Drug Administration At this time we do not have sufficient information to duplicate the circumstances that led to the incident in Panama or to determine which versions of the radiation treatment planning software may have a similar problem Because the specific reason for the overexposures is still unknown we are notifying all users of the RTP and Attachment 1 IN 2001 08 Supp 2 Page 2 of 2 DSS software regardless of software version or therapy modality sealed source teletherapy or linear accelerator Multidata will continue to evaluate these circumstances and attempt to duplicate the problem We will provide all users additional information describing the problem as soon as the specific sequence of events involving the interaction between the user and the system are found If a corrective action is required as a result of this incident Multidata will make this correction available to all customers Your Response In the meantime Multidata urges all customers to maintain quality assurance and review their operating procedures Particular emphasis should be given to the following e Foll
8. on These improper blocks will produce substantially higher values 50 to 500 for MU or TIME ON than what one would expect by partially blocking an open field Any time a beam shaping technique alters the MU by more than the Open Field Output Factor range the plan configuration must be investigated Fig 1 Incorrect crossing block outline When an improper block not a true polygon has been entered a solid line connects the two block icons in the slice transverse view Fig 2 as shown below Ss Fig 2 Solid line connecting block icons in the transverse view Fig 3 Safe aperture definition with a single continuous line Whenever this solid line is present the data entered and plan results should be verified to determine that the results are valid and as expected Please note that some properly entered blocks including those that extend over three sides of the field Fig 3 will also display this solid line To assure that data entry defining an aperture shape is correct one should use two blocks Fig 4 Note that outlines of different blocks may overlap however if only one block is used it is essential to verify that the block outline does not cross itself Fig 3 Fig 4 Recommended aperture definition using two separate blocks
9. ow the instructions in the user manual The calculation modules other programs and data on radiation used in the treatment planning system have certain limitations which are specified in the user manual Do not attempt to operate the system outside these limitations as the software could produce misleading or incorrect results e Follow a written quality assurance procedure for changes in treatment protocol which should include independent verification of dose to the prescription points as calculated by the computer for each individual patient and before the first treatment e Perform verification measurements using a phantom or other procedures as may be required for those exceptional cases of complicated treatments for which manual calculations may not be practical or difficult to interpret We ask that you confirm receipt of this letter by July 6 2001 Notify Jennifer Davis by telephone at 800 225 1130 by facsimile FAX at 314 968 6443 or by E mail at jdavis multidata systems com Let us know if you are aware of any problems similar to the incident in Panama If you no longer use the treatment planning system let us know so that you can be removed from the user list If you have any questions concerns or doubt about the proper operation of the treatment planning system please contact us Multidata Systems International Corp AN Mick Conley General Business Manager Attachment 2 IN 2001 08 Supp 2 Page 1 of 2 August
10. t is available from IAEA and can be ordered from its web site at http www iaea org worldatom Books NewReleases book26 shtml The company that supplied the treatment planning software Multidata Systems International Corporation Multidata in St Louis Missouri issued a Medical Device Safety Alert on June 22 2001 Attachment 1 and an Urgent Notice on August 10 2001 Attachment 2 The Urgent Notice explains that certain improper data entries will be accepted by the software but will result in incorrect dose calculations Multidata is developing a filter program to address this problem Discussion According to the IAEA report one method the Panamanian hospital staff used for the data entry of shielding blocks caused the treatment planning system to calculate incorrect treatment times ML012390161 IN 2001 08 Supp 2 Page 2 of 3 Specifically the staff modified its procedures and entered data for multiple shielding blocks together digitized the blocks as if they were a single block The data were accepted by the treatment planning system but the software calculated incorrect treatment times Using incorrect treatment times resulted in significant radiation overexposures to patients The hospital staff did not perform independent verification of the computer calculated treatment times so the errors were not identified before treatment The IAEA report states that there were several characteristics of
11. the computerized treatment planning system that made it relatively easy for the error to occur These were 1 Several different ways of digitizing blocks were accepted by the computer treatment planning system 2 There was no warning on the computer screen when blocks were digitized in an unacceptable way i e any way that is different from the one prescribed in the manual and 3 When blocks were digitized incorrectly the treatment planning system produced a diagram that was the same as that produced when the data were entered correctly thereby giving the impression that the calculated results were correct The Multidata Medical Device Safety Alert dated June 22 2001 urges customers to follow the instructions in the user manual and emphasizes that users should not attempt to operate the system outside the limitations stated in the user manual All persons involved in radiation therapy are encouraged to review both the information related to this incident and your treatment planning procedures to ensure that both your procedures and written quality management program required by 10 CFR 35 32 are adequate to avoid similar radiation therapy errors The event in Panama demonstrates that licensees should always be alert to the possibility of introducing unintended errors into the treatment planning process In particular note the importance of independent verification of computer generated patient treatment plans In addition
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