Yakima radiotherapy accident, 1987 (original) (raw)

Database of radiological incidents and related events--Johnston's Archive

compiled by Wm. Robert Johnston
last modified 13 June 2004

**Date:**17 January 1987

**Location:**Yakima Valley Memorial Hospital, Yakima, Washington, USA

**Type of event:**radiotherapy accident

Description:

A defect in the computer program controlling the Therac-25 radiation therapy accelerator resulted in overexposures to patients. A male patient was overexposed (estimated dose 8000-10000 rads localized), immediately reporting pain and developing skin burns later that day. The patient, although previously suffering from terminal cancer, died in April of complications related to the overexposure.

**Consequences:**1 fatality.

References:

• Leveson, Nancy, and Clark S. Turner, July 1993, "An investigation of the Therac-25 accidents," IEEE Computer, 26:18-41, on line at Computer Science at Virginia Tech [http://courses.cs.vt.edu/~cs3604/lib/Therac_25/Therac_3.html].

© 2004 by Wm. Robert Johnston.
Last modified 13 June 2004.
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