Medical Issues Associated with
Radiotherapy Accidents
ALBERT Wiley, JR., BNE, MD, PhD, FACR
DIRECTOR,REAC/TS and WHO COLLABORATING
CENTER at OAK RIDGE
EMERITUS PROFESSOR,UNIV. WISC.-MADISON
albert.wiley@orise.orau.gov
IAEA International Conference on Radiation
Protection in Medicine,Bonn,Germany
December,2012
1
Where Do Radiation Accidents Occur?

Irradiation facilities

Nuclear reactors

Isotope production facilities

Materials testing (sealed sources)

Materials testing (x-ray devices)

X-ray and radiotherapy devices (medicine, research)

Unsealed radionuclides (medicine, research)

Transportation

Military
Source: REAC/TS Radiation Accident Registry
DEATHS from RADIATION ACCIDENTS WORLDWIDE 1944-2012
*Recorded in REAC/TS RADIATION ACCIDENT REGISTRY
United States
New Mexico
3
Ohio
10
Oklahoma
1
Pennsylvania 1
Rhode Island 1
Texas
9
Wisconsin
1
Total U.S. 26
Other
Algeria
Argentina
Belarus
Brazil
Bulgaria
China (PR)
Costa Rica
Egypt
El Salvador
Estonia
Israel
Italy
India
2
Japan
2
1
Marshall Isl
1
1
Mexico
5
4
Morocco
8
1
Norway
1
6
Panama
5
7
Russia
5
2
Spain
10
1
Thailand
3
1
USSR
29
1
UK
3
1
Yugoslavia
1
1
Total Non-U.S.
102
DEATHS FROM MEDICAL and OTHER RADIATION ACCIDENTS
WORLDWIDE 1944-2012
*RECORDED in REAC/TS RADIATION ACCIDENT REGISTRY
United States
New Mexico
3
Ohio
10
Oklahoma
1
Pennsylvania 1
Rhode Island 1
Texas
9
Wisconsin
1
Total U.S. 26
Other(non US)
Algeria
Argentina
Belarus
Brazil
Bulgaria
China (PR)
Costa Rica
Egypt
2
1
1
4
1
6
7
2
Japan
Marshall Isl
Mexico
Morocco
Norway
Panama
Russia
Spain
2
1
5
8
1
5
5
10
Estonia
Israel
Italy
India
El Salvador
1
1
1
1
1
USSR
UK
Yugoslavia
29
3
1
Thailand 3
MAJOR RADIATION “ACCIDENTS” WORLDWIDE
1944 – Mar 2012
United States Deaths
Cause
Medical misadministration 60Co –
wrong graph paper used –
underestimate of source strength
and increased time of exposure
Ohio
10
Texas
9
2 teletherapy equipment malfunction “54”– 25MeV
7 90Y loss from therapeutic microspheres
Pennsylvania
1
Retained brachytherapy source –
Wisconsin
1
Medical misadministration –
“milli” Ci
New Mexico
3
Criticality
Rhode Island
1
Criticality
Oklahoma
1
Radiography source - probable suicide
Total
26
192Ir
198Au
– miscalculation of “micro” to
MAJOR RADIATION “ACCIDENTS” WORLDWIDE
1944 – Mar 2012
ACUTE, ASSOCIATED, AND NON-RADIATION DEATHS
United States Deaths
Cause
Medical misadministration 60Co – wrong
graph paper used – underestimate of source
strength and increased time of exposure
2 teletherapy equipment malfunction “54”–
25MeV
7 90Y loss from therapeutic microspheres
Ohio
10
Texas
9
Pennsylvania
1
Retained brachytherapy source –
Wisconsin
1
Medical misadministration – 198Au –
miscalculation of “micro” to “milli” Ci
New Mexico
3
Criticality
Rhode Island
1
Criticality
Oklahoma
1
Radiography source - probable suicide
Total
26
192Ir
Malfunction “54” Background



The most serious computer related accidents to
date
Therac 25 was a medical linear accelerator, a linac
developed by Atomic Energy Of Canada Ltd (AECL)
11 Therac 25s were installed - 5 in US, 6 in Canada
Background (Continued)


Therac 25 was derived from its previous
version Therac 6 and Therac 20
Differences from Therac 20
- Software is responsible for safety
- Hardware safety interlocks removed
- Less space and more economical
Accidents



3 June 1985 – patient at Marietta GA received
overdose
26 July 1985 – Hamilton ON patient severely
burned, died November 1985
December 1985 – patient in Yakima WA
received overdose

21 March 1986 – Tyler TX accident

11 April 1986 – 2nd Tyler TX accident

17 January 1987 – 2nd Yakima WA accident
MAJOR RADIATION “ACCIDENTS” WORLDWIDE
1944 – Mar 2012
ACUTE, ASSOCIATED, AND NON-RADIATION DEATHS
United States Deaths
Cause
Medical misadministration 60Co – wrong graph paper used –
underestimate of source strength and increased time of exposure
Ohio
10
Texas
9
2 teletherapy equipment malfunction “54”– 25MeV
7 90Y loss from therapeutic microspheres
Pennsylvania
1
Retained brachytherapy source –
192Ir
Medical misadministration –
198Au – miscalculation of “micro”
to “milli” Ci
Wisconsin
1
New Mexico
3
Criticality
Rhode Island
1
Criticality
Oklahoma
1
Radiography source - probable suicide
Total
26
DEATHS FROM RADIATION “ACCIDENTS” in USA
1944 – Mar 2012
United States Deaths
Ohio
10
Texas
9
Cause
Medical misadministration 60Co – wrong graph paper used –
underestimate of source strength and increased time of exposure
2 teletherapy equipment malfunction “54”– 25MeV
7 90Y loss from therapeutic microspheres
Retained brachytherapy source –
192Ir
PA
1
Wisconsin
1
Medical misadministration –
“milli” Ci
New Mexico
3
Criticality
Rhode Island
1
Criticality
Oklahoma
1
Radiography source - probable suicide
Total
26
198Au
– miscalculation of “micro” to
PENN. ACCIDENT CLINICAL
HISTORY


82 year old white female presented in
November 1992 with a recurrent
squamous cell cancer of the anus
She had received prior treatment which
included external beam radiation and
chemotherapy (1991)
TREATMENT PLANNED
High Dose Rate (HDR) implant was
prescribed using a 4.22 Curie
iridium-192 source to traverse four
perianal catheters (previously
stitched in place) over a total
treatment time of several minutes
RADIATION ACCIDENT



HDR source unknowingly broke off
inside one of the catheters
Patient was transferred from the
cancer treatment center back to the
nursing home with the catheters in
place
A second HDR treatment was
scheduled the following week
DAY ONE (16 NOVEMBER 1992)
2 PM (4.5 hours post HDR)
- first episode of vomiting
- pelvic pain
2:30 PM (5 hours post HDR)
- continued vomiting
5:30 PM (8 hours post HDR)
- continued vomiting and
pain
7:30 PM (10 hours post HDR)
- difficulty moving bowels
- difficulty voiding
- tachycardia (P = 110)
DAY FOUR (19 NOVEMBER 1992)
(continued)
7 PM
- small piece of gray-black tissue one
inch long stuck to one of the
catheters which was loose
- continued nausea and pelvic pain
10:30 PM
- pain radiating from vagina to
abdomen with hypoactive bowel sounds
- skin turgor poor and skin cool/dry
DAY SIX (21 NOVEMBER 1992)
8 AM
- pale, weak, tachycardia
- rectal area reddened, swollen, and
“hot” to the touch; continued diarrhea
3 PM
- no dyspnea but occasional congested
weak cough
5 PM
- respirations “congested and labored”
for which oxygen given
- difficult to arouse; extremities cool
11 PM
- patient expired
PATIENT ABSORBED DOSE ESTIMATES
FOR 4.22 CURIE Ir-192 SOURCE OVER 92.75
HRS
Rectum (closest point)
Bladder (closest point)
Small bowel (closest point)
Small bowel (median point)
Left kidney (median point)
Right kidney (median point)
Bone Marrow (L1 Vertebral Body)
Heart (median point)
Lung (median point)
Brain (median point)
7,770 Gy
2,080 Gy
330 Gy
95.8 Gy
36.7 Gy
31.2 Gy
19.7 Gy
9.4 Gy
6.1 Gy
0.9 Gy
PERSONNEL DOSES RECEIVED
Dose Range (cGy)
0.0 – 0.5
0.5 – 1.0
1.0 – 5.0
5.0 – 10
10 – 15
15 – 20
Number of
Individuals
42
11
20
13
7
1
94 TOTAL
CONCLUSIONS


No other acute radiation effects seen in staff,
other patients, or visitors, but be prepared to
deal with unexpected staff/public exposures in
such accidents.
Cytogenetic studies performed at REAC/TS
(ORISE) in Oak Ridge TN demonstrated that a
certain group of staff and patients had a
significant number of chromosomal
abnormalities in peripheral lymphocytes, but
fortunately only stochastic and no deterministic
dose levels were observed. Psychological/legal
issues!
NRC CORRECTIVE ACTIONS – REQIREMENTS FOR
HIGH DOSE RATE (HDR) RADIATION TREATMENT




General implementation of a safety culture by:
Requiring that physician and physicist must be at the
HDR console during treatment.
An independent radiation survey (separate from a
functioning treatment room “area” monitor) must be
done with a hand-held instrument prior to removal of
patient from the HDR treatment room.
HDR emergency procedures/supplies must be
immediately available /reviewed and practiced
periodically.
Bialystok Radiotherapy Accident:
In 2001, 5 patients were
overexposed to linear accelerator
radiations due to faults in the dose
monitoring system and the failure
of an electronic safety interlock ,
following
sudden electric power transits.
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Diagnosis/Evaluation



PE and Laboratory tests- serial CBCs,
amylase,CB, electron spin resonance
(ESR),some new proteomic and genomic
organ specific blood tests offer promise.
Imaging – MRI (with angiography),
thermography, ultrasound, blood pooling
nuclear studies, other radiographic studies
as indicated
Daily serial digital color photographs –time
dependent SKIN reactions may often be
good dosimeters.
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Special Radiation Injury Issues
 Management of radiation injury is often
medically and socially complex(morale
problems for both patient and staff !)
 There may be incidental disfigurement,
pain control and malfunction of multiple
organ systems(ie, breast cancer/chest
wall radiation fields may also injure heart,
lungs, etc.)
 Psychosocial well-being of the patient
must be constantly addressed in the longterm healthcare plan.
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Summary
The presented examples demonstrate the primary causes
for radiotherapy accidents: “Human Factors”

Lost or mishandled sources

Pharmacology ,radiation unit issues with unsealed
sources

Bypassing Interlocks


Calibration/programming/computer/treatment planning
errors (IAEA DOSIMETRY LAB) and IAEA SAFRON
program(rpop.iaea.org/safron)
Inadequate “clinical monitoring of signs/symptoms” and
“dose monitoring” DURING treatment(ie,
training/written procedures and better on-line physics
monitoring -- ? daily TL catheters in treatment field,”invivo dosimeters” for cyberknife,IMRT,etc.)
Possible Medical Countermeasures

Following an accident, what, if anything
can be done medically to mitigate the
radiation injury?
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Something “to wish for”-- in people—this is mouse data!
Antioxidant diet supplementation starting 24 hours
after exposure reduces radiation lethality. Radiat Res
173(4): 462-468 (2010)
Some Possible Countermeasures:

Vitamin E: TS, DT3

Genistein, EUK-207

Curcumin derivatives

Mn Porphyrin - AEOL 10150


Antioxidants in combination - Genistein +
EUK-207 (a SOD-catalase mimetic)
Others(? Steroids,anti-coagulants,antihistamines,pentoxphylamine,ace
inhibitors,interferon,cytokines,HBO,etc.)
Thank you!
Questions?
Note: Some of the slides of the Penn. HDR accident were
from D. Flynn,MD ; and all of slides of the Bialystok, Poland
accident came from IAEA STI/PUB/P1180,2004.
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