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

Yakima radiotherapy accident, 1985-1986

compiled by Wm. Robert Johnston
last modified 13 June 2004

Date: September 1985-January 1986

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

Type of event: radiotherapy accident


A defect in the computer program controlling the Therac-25 radiation therapy accelerator resulted in overexposures to patients. A woman who received several treatments from September 1985 to 6 January 1986 developed radiation burns which were not recognized as radiation injuries until another injury occurred in 1987.

Consequences: 1 injury.


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