1083 / 1359
Major RT accidents
Identification
Cause of the accident
Consequence
Number of
patients
involved
USA (1974-1976)
Wrong decay curve for Co-60
Overdose (up to 50%)
426
UK (1982-1990)
Double correction of MU by ISQ
after the implementing a new TPS.
Underdose (5-30%)
1045
Costa Rica (1996)
Error in the calibration of a Cobalt
unit. Misunderstanding of the
time units (0.3 minutes were taken
as 30 seconds instead of 18
seconds)
Overdose (up to 60%)
115
Panama (2000)
Forcing a fifth block in a TPS that
admitted four as a maximum
The time was doubled.
100% overdose.
28
USA and Canada
(1985-1987)
Software of an old accelerator
was incorporated in a new
accelerator. Errors in modality
and energy.
6 (3 of them
died)
Poland (2001)
Two faults in two circuits at the
same time + inoperative interlock
lead to the accelerator operating
with an ineffective beam
monitoring system.
Overdose (doses in one
fraction of 80-100 Gy)
5
USA (1987-1988)
After changing a cobalt source all
files except one (dose calculation
with trimmers) were actualised in
the TPS.
One new doctor decided treating
patients with the trimmers.
Treatment time was calculated
using the dose-rate of the old
source
Overdose (up to 75%)
33
Spain (1990)
After a breakdown of a linear
accelerator a company technician
repaired it. However a meter
display indicated an energy
selection problem. This indication
was disregarded. All patients
treated with electron beams were
treated with the maximum
available electron energy.
Overdose
27
France (2004-
2005)
TPS calculation performed with
static wedges while the patient
was treated with dynamic wedges
Overdose (by 7%-34%)
23
Entrance in vivo
dose
measurements