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Medical Devices
Radiation Safety
Medical Devices Medical Devices
Radiation SafetyRadiation Safety
Visiting Professor
DOIN-DEN / UFPE
Recife, Pernambuco, Brazil
Visiting ProfessorVisiting Professor
DOINDOIN--DEN / UFPEDEN / UFPE
Recife, Pernambuco, BrazilRecife, Pernambuco, Brazil
Cari BorrCari Borráás, D.Sc., FACR, FAAPMs, D.Sc., FACR, FAAPM
CoCo--Chair, IUPESMChair, IUPESM
Health Technology Health Technology
Task GroupTask Group
2
Radiological
equipment has
changed a bit since
the early days...
Radiological
equipment has
changed a bit since
the early days...
3PET/CTPET/CT
DRDR
CTCTCT
4
First
Co-60
Unit
(1951)
First First
CoCo--60 60
Unit Unit
(1951)(1951)
CsCs--137 137
TeletherapyTeletherapy
(1960(1960’’s)s)
Orthovoltage XOrthovoltage X--Ray (1990Ray (1990’’s)s)
Linac Linac
with with
IGRT IGRT
(200s)(200s)
External Beam Therapy
55
BrachytherapyBrachytherapy
Ra
Needles
1929
Ra
Needles
1929
Manchester
Applicator
Manchester
Applicator
LDR
1970 -
1980
LDR
1970 -
1980
HDR
1990
HDR
1990
1950
-
1960
1950
-
1960
Electronic
Brachytherapy
2000
Electronic
Brachytherapy
2000
Cs-137 Ir-192
Miniature
X-Ray
Tube
R. Mackie 2009
77
Global Annual Number of Radiological Exams
and Treatments per 1,000 People
Global Annual Number of Radiological Exams Global Annual Number of Radiological Exams
and Treatments per 1,000 Peopleand Treatments per 1,000 People
PracticePractice 19971997-- 2007 2007 1991 1991 -- 19961996
420420
(1,230)(1,230)
5.65.6
(19)(19)
1.01.0
(1.9)(1.9)
X RaysX Rays
Nuclear MedicineNuclear Medicine
RadiotherapyRadiotherapy
562562
(1,607)(1,607)
5.15.1
(19)(19)
0.80.8
(2.4)(2.4)
( Data for HCL I )( Data for HCL I )UNSCEAR 2008UNSCEAR 2008
Annual per Caput Effective Dose (mSv)
for theUnited States Population
Annual per Caput Effective Dose (mSv) Annual per Caput Effective Dose (mSv)
for theUnited States Populationfor theUnited States Population
8
19801980 20062006
Medical: 3.0
UNSCEAR2008
Radiation RisksRadiation RisksRadiation Risks
▲ External
▲ Internal
▲▲ ExternalExternal
▲▲ InternalInternal
9
ll AbsorptionAbsorption
ll InhalationInhalation
ll IngestionIngestion
Contamination PathwaysContamination Pathways
10
Deterministic Effects
Radiation effects for which generally a threshold
level of dose exists above which the severity of
the effect is greater for a higher dose.
Deterministic EffectsDeterministic Effects
Radiation effects for which generally a threshold Radiation effects for which generally a threshold
level of dose exists above which the severity of level of dose exists above which the severity of
the effect is greater for a higher dose. the effect is greater for a higher dose.
Stochastic Effects
Radiation effects, generally occurring without a
threshold level of dose, whose probability is proportional
to the dose and whose severity is independent of the dose.
Stochastic EffectsStochastic Effects
Radiation effects, generally occurring without a Radiation effects, generally occurring without a
threshold level of dose, whose probability is proportional threshold level of dose, whose probability is proportional
to the dose and whose severity is independent of the dose.to the dose and whose severity is independent of the dose.
1111
Effects of Cell DeathEffects of Cell Death
DDoseose
((mGy)mGy)
Probability of DeathProbability of Death
DD
100%100%
CoCo--60 Radiotherapy 60 Radiotherapy
OverexposureOverexposure
Panama 2000Panama 2000--20012001
Whole body response : adultWhole body response : adultWhole body response : adult
Acute irradiation syndromeAcute irradiation syndromeAcute irradiation syndrome
12
Chronic irradiation syndrome
Surv
ival tim
e
Dose
Lethal dose 50 / 30BMS(bone
marrow)
GIS(gastro
intestinal) CNS(central nervous
system)
1-10 Gy
10-50 Gy
> 50 Gy
•Whole body clinic
of a partial-body
irradiation
•Mechanism:
Neurovegetative
disorder
•Similar to a sick
feeling
•Quite frequent in
fractionated
radiotherapy
Skin InjuriesSkin InjuriesSkin Injuries
13
Interventional Radiology
Over-Exposure, USA 1991
Interventional Radiology Interventional Radiology
OverOver--Exposure, USA 1991Exposure, USA 1991
Effects in the EyeEffects in the EyeEffects in the Eye
▲ Eye lens is highly radiosensitive.
▲ Coagulation of proteins occur with doses greater than 2 Gy.
▲ There are 2 basic effects:
▲▲ Eye lens is highly radiosensitive.Eye lens is highly radiosensitive.
▲▲ Coagulation of proteins occur with doses greater than 2 Gy.Coagulation of proteins occur with doses greater than 2 Gy.
▲▲ There are 2 basic effects:There are 2 basic effects:
14
> 0.15> 0.155.05.0
Visual Visual
impairment impairment
(cataract)(cataract)
> 0.1> 0.10.50.5--2.02.0Detectable Detectable
opacitiesopacities
Sv/year for Sv/year for
many yearsmany years
Sv single brief Sv single brief
exposureexposure
EffectEffect
15
Deterministic Effects
Radiation effects for which generally a threshold
level of dose exists above which the severity of
the effect is greater for a higher dose.
Deterministic EffectsDeterministic Effects
Radiation effects for which generally a threshold Radiation effects for which generally a threshold
level of dose exists above which the severity of level of dose exists above which the severity of
the effect is greater for a higher dose. the effect is greater for a higher dose.
Stochastic Effects
Radiation effects, generally occurring without a
threshold level of dose, whose probability is proportional
to the dose and whose severity is independent of the dose.
Stochastic EffectsStochastic Effects
Radiation effects, generally occurring without a Radiation effects, generally occurring without a
threshold level of dose, whose probability is proportional threshold level of dose, whose probability is proportional
to the dose and whose severity is independent of the dose.to the dose and whose severity is independent of the dose.
Cancer Heritable Effects
16
1717
Frequency (%)
10 20 30 40Absorbed dose (Gy)
Genetic (Heritable) Effects
(Mutations)
Genetic (Heritable) Effects
(Mutations)
10
5
0
Fruit Fly Experiments
Fruit Fly Fruit Fly
ExperimentsExperiments
1818
Genetic EffectsGenetic EffectsGenetic Effects
▲ Ionizing radiation is known to cause hereditary
mutations in many plants and animals
BUT
▲ Intensive studies of 70,000 offspring of the atomic
bomb survivors have failed to identify an increase
in congenital anomalies, cancer, chromosome
aberrations in circulating lymphocytes or
mutational blood protein changes.
▲▲ Ionizing radiation is known to cause hereditary Ionizing radiation is known to cause hereditary
mutations in many plants and animalsmutations in many plants and animals
BUTBUT
▲▲ Intensive studies of 70,000 offspring of the atomic Intensive studies of 70,000 offspring of the atomic
bomb survivors have failed to identify an increase bomb survivors have failed to identify an increase
in congenital anomalies, cancer, chromosome in congenital anomalies, cancer, chromosome
aberrations in circulating lymphocytes or aberrations in circulating lymphocytes or
mutational blood protein changes.mutational blood protein changes.
1919
ICRP Detriment-Adjusted Nominal Risk
Coefficient for Cancer and Heritable Effects
(ICRP 103, 2007)
(10-2 Sv-1 – Percent per Sievert)
ICRP DetrimentICRP Detriment--Adjusted Nominal Risk Adjusted Nominal Risk
Coefficient for Cancer and Heritable Effects Coefficient for Cancer and Heritable Effects
(ICRP 103, 2007)(ICRP 103, 2007)
(10(10--22 SvSv--11 –– Percent per Sievert)Percent per Sievert)
Exposed Exposed
PopulationPopulation
Cancer Cancer
InductionInduction
Heritable Heritable
EffectsEffects
Whole 5.5 0.2
Adult 4.1 0.1
20
Radiation Radiation
Therapy Therapy
PublicationsPublications
Unintended Unintended
ExposureExposure
ss
ICRP 112,
2010
20082008
20002000
ICRP 112, 2010
21
ProblemProblem CountryCountry YearYearPatients Patients
OverdosedOverdosed
CoCo--60Mis60Mis--
calibrationscalibrations
USA 1974-1976 426
Germany 1986-1987 86
UK 1988 207
Costa Rica 1996 114
Hardware / Hardware /
Software Software
Linear Linear
AcceleratorsAccelerators
Canada &
USA1985-1987 3
Spain 1990 27
Poland 2001 5
TreatmentPlTreatmentPl
anninganning
USA 1987-1988 33
Panama 2000 28
22
ICRP 2010ICRP 2010
621 Radiotherapy Mistakes (NYT)*
New York State, 2001 - 2008
621 Radiotherapy Mistakes (NYT)*621 Radiotherapy Mistakes (NYT)*
New York State, 2001 New York State, 2001 -- 20082008
* The information presented is that reported in the New York * The information presented is that reported in the New York
Times (NYT) by Walt Bogdanich in January 2010. No Times (NYT) by Walt Bogdanich in January 2010. No
independent verification for accuracy has been performed.independent verification for accuracy has been performed.
Nr. PatientsNr. Patients Cause of overexposureCause of overexposure
133 Beam-shaping devices error
284 Wrong target
50 Wrong patient
1 Faulty calculation
2 Lack of tests after machine repair
23
24
2 Radiotherapy Mistakes (NYT)*
New York City, 2005
(Patients died in 2007)
2 Radiotherapy Mistakes (NYT)*2 Radiotherapy Mistakes (NYT)*
New York City, 2005New York City, 2005
(Patients died in 2007)(Patients died in 2007)
Cancer Cancer
SiteSite Cause of overexposureCause of overexposureComments / Comments /
ConsequencesConsequences
Tongue
Multileaf collimator for
IMRT did not work.
Open field instead.
(Varian)
3 of 5 fractions given. Severe
morbidity. Physicist checks RX
Dose given : 7 times prescribed
Hospital and Varian sued
Varian modifies software
Breast Wedge not in the beam.
27 of 28 fractions given.
Morbidity appears at the end.
Dose given: 3.5 times prescribed
25
Radiotherapy Mistakes (NYT)*
Other USA States
Radiotherapy Mistakes (NYT)*Radiotherapy Mistakes (NYT)*
Other USA StatesOther USA StatesState
Year
Nr.
Patients
Cancer
Site
Cause of
overexposure
Overdose
(%)
Florida
200577 Brain Linac miscalibration 50
Louisiana
20051 Prostate
Wrong CT scan for
TPS
100 (38
fractions)
Texas
20041 Prostate
EBT + Brachy : No
dose prescription, no
post-implant calcs
?
Ohio
20061 Breast
Incorrect
magnification factor100
Radiotherapy Mistakes
Veterans Affairs Hospitals
Radiotherapy MistakesRadiotherapy Mistakes
Veterans Affairs HospitalsVeterans Affairs Hospitals
LocationLocation
YearYearNr. PatientsNr. Patients Cancer SiteCancer Site
Cause of Cause of
overexposureoverexposure
Philadelphia Philadelphia
PennsylvaniaPennsylvania
2002 2002 -- 20082008
9797 ProstateProstate
Incorrect Incorrect
placement ofplacement of
II--125 seeds125 seeds
No dosimetryNo dosimetry
East OrangeEast Orange
New Jersey New Jersey
20062006
5656
36 overirradiated36 overirradiated
20 had 20 had ““errorserrors””
ProstateProstate
Head & NeckHead & Neck
LungLung
BreastBreast
2 Others2 Others
No staff No staff
training in training in
IMRTIMRT
No experienceNo experience
No QC, QANo QC, QA
26
27
28
29C. Borrás V ALFIM 2010
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