This statement informs radiation therapy system users of radiation overexposures that occurred at Panama's National Institute of Oncology. The statement describes FDA's investigation and provides recommendations for radiation therapy system users.
Twenty-eight patients at the Panama National Institute of Oncology were overexposed to radiation during radiation therapy for colon, prostate, and cervical cancer. The overexposures ranged from 20 to 100 percent over the prescribed dose. Reports to date indicate that nine of the patients have died, with five of the deaths attributed to radiation overexposure. Many of the remaining patients are expected to develop serious radiation related complications. Equipment used at the Institute included a Theratron 780-C Cobalt 60 teletherapy system manufactured by Theratronics Incorporated of Ontario, Canada, and radiation treatment planning software manufactured by Multidata Systems International Corporation of St. Louis, MO.
Review of the available reports indicates the following factors contributed to the overexposures:
- A lack of treatment plan verification at the Panama National Institute of Oncology
- The method of entering beam block data into the Multidata software
- Interpretation of beam block data by the Multidata software
Available information does not suggest that a failure or malfunction of the Theratronics teletherapy system caused or contributed to the reported events.
FDA is investigating these incidents with the International Atomic Energy Agency (IAEA), the Pan American Health Organization (PAHO), the Nuclear Regulatory Commission (NRC), and Multidata to determine the cause of the overexposures and provide solutions. FDA is investigating whether there have been similar problems in the U.S. or abroad.
FDA recommends that radiation therapy system users take the following action:
- Review available reports for additional information:
- June 18, 2001 joint statement from the American College of Radiology, American Society for Therapeutic Radiology and Oncology, and American Association of Physicists in Medicine
- June 9, 2001 IAEA Termination Report
- June 6, 2001 NRC Information Notice (Supplement 1)
- Contact Multidata directly if you use Multidata products and have specific questions on the beam block function or another aspect of the software:
- On the web at http://www.multidata-systems.com
- By phone at (314) 968-6880
- Consider submitting a MedWatch report to FDA if you are aware of radiation treatment planning software problems either related to this incident or otherwise:
- On the web at https://www.accessdata.fda.gov/scripts/medwatch
- By phone at (800) 332-1088
- By fax at (800) 332-0178
- Follow quality assurance procedures to verify treatment plans by independent means, which may include manual calculations or measurement of radiation dose.
FDA will release new information as it becomes available.