ISO/ASTM 51939:2005

INTERNATIONAL ISO/ASTM
STANDARD 51939
Second edition
2005-05-15
Practice for blood irradiation dosimetry
Pratique de la dosimétrie pour l’irradiation du sang
Reference number
© ISO/ASTM International 2005
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ii © ISO/ASTM International 2005 – All rights reserved

Contents Page
1 Scope . 1
2 Referenced Documents . 1
3 Terminology . 1
4 Significance and use . 3
5 Type of facilities and modes of operation used for blood irradiation . 4
6 Radiation source characteristics . 4
7 Dosimetry systems . 4
8 Installation qualification . 6
9 Operational qualification . 7
10 Performance qualification . 8
11 Routine product processing . 9
12 Measurement uncertainty . 9
13 Keywords . 10
Annexes . 10
Bibliography . 12
Table 1 Examples of reference-standard dosimeters . 5
Table 2 Examples of transfer-standard dosimeters . 5
Table 3 Examples of routine dosimeters . 5
Table A2.1 Recommended quality assurance steps for blood irradiation . 12
© ISO/ASTM International 2005 – All rights reserved iii

Foreword
ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are circulated to the member bodies for
voting. Publication as an International Standard requires approval by at least 75% of the member bodies
casting a vote.
ASTM International is one of the world’s largest voluntary standards development organizations with global
participation from affected stakeholders. ASTM technical committees follow rigorous due process balloting
procedures.
A project between ISO and ASTM International has been formed to develop and maintain a group of
ISO/ASTM radiation processing dosimetry standards. Under this project, ASTM Subcommittee E10.01,
Dosimetry for Radiation Processing, is responsible for the development and maintenance of these dosimetry
standards with unrestricted participation and input from appropriate ISO member bodies.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. Neither ISO nor ASTM International shall be held responsible for identifying any or all such patent
rights.
International Standard ISO/ASTM 51939 was developed by ASTM Committee E10, Nuclear Technology and
Applications, through Subcommittee E10.01, and by Technical Committee ISO/TC 85, Nuclear energy.
This second edition cancels and replaces the first edition (ISO/ASTM 51939:2002), which has been
technically revised.
iv © ISO/ASTM International 2005 – All rights reserved

Standard Practice for
Blood Irradiation Dosimetry
This standard is issued under the fixed designation ISO/ASTM 51939; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision.
1. Scope 51261 Guide for Selection and Calibration of Dosimetry
Systems for Radiation Processing
1.1 This practice outlines irradiator installation qualifica-
51275 Practice for Use of a Radiochromic Film Dosimetry
tion, operational qualification, performance qualification, and
System
routine product processing dosimetric procedures to be fol-
51310 Practice for Use of a Radiochromic Optical
lowed in the irradiation of blood and blood components by the
Waveguide Dosimetry System
blood-banking community. If followed, these procedures will
51400 Practice for Characterization and Performance of a
help to ensure that the products processed with ionizing
High-Dose Radiation Dosimetry Calibration Laboratory
radiation from gamma, X-rays (bremsstrahlung), or electron
51538 Practice for Use of the Ethanol-Chlorobenzene Do-
sources receive absorbed doses within a predetermined range.
simetry System
1.2 This practice covers dosimetry for the irradiation of
51539 Guide for the Use of Radiation-Sensitive Indicators
blood for these types of irradiators: self-contained irradiators
137 60
51607 Practice for Use of the Alanine-EPR Dosimetry
(free-standing irradiators) utilizing Cs, Co or X-rays
System
(bremsstrahlung), teletherapy units, and electron accelerators.
51608 Practice for Dosimetry in an X-ray (Bremsstrahlung)
The absorbed dose range for blood irradiation is typically 15
Facility for Radiation Processing
Gyto50Gy.Insomejurisdictions,theabsorbeddoserangefor
51707 Guide for Estimating Uncertainties in Dosimetry for
blood irradiation is 25 Gy to 50 Gy.
Radiation Processing
1.3 The energy range is typically from approximately 40
51956 Practice for Thermoluminescent Dosimetry (TLD)
keV to 5 MeV for photons, and up to 10 MeV for electrons.
for Radiation Processing
1.4 This practice also covers the use of radiation-sensitive
52116 Practice for Dosimetry for a Self-Contained Dry-
indicators for the visual and qualitative indication that the
Storage Gamma-Ray Irradiator
product has been irradiated.
2.3 International Commission on Radiation Units and
1.5 This standard does not purport to address all of the
Measurements Reports (ICRU):
safety concerns, if any, associated with its use. It is the
ICRU 60 Fundamental Quantities and Units for Ionizing
responsibility of the user of this standard to establish appro-
Radiation
priate safety and health practices and to determine the
2.4 Guidelines on Blood Irradiation:
applicability or regulatory limitations prior to use.
Guidelines on Gamma Irradiation of Blood Components for
2. Referenced Documents the Prevention of Transfusion-associated Graft-versus-
host Disease, Prepared by the BCSH Blood Transfusion
2.1 ASTM Standards:
Task Force
E170 Terminology Relating to Radiation Measurements
Recommendations Regarding License Amendments and
and Dosimetry
Procedures for Gamma Irradiation of Blood Products,
E1026 Practice for Using the Fricke Reference Standard
(1993) US Food and Drug Administration
Dosimetry System
Guidance for Industry, Gamma Irradiation of Blood and
E2304 Practice for Use of a LiF Photo-Fluorescent Film
BloodComponents:APilotProgramforLicensing(2000)
Dosimetry System
US Food and Drug Administration
2.2 ISO/ASTM Standards:
3. Terminology
3.1 Definitions:
This practice is under the jurisdiction of ASTM Committee E10 on Nuclear 3.1.1 absorbed dose (D)—quantity of ionizing radiation
Technology and Applications and is the direct responsibility of Subcommittee
energy imparted per unit mass of a specified material. The SI
E10.01 on Dosimetry for Radiation Processing, and is also under the jurisdiction of
unit of absorbed dose is the gray (Gy), where 1 gray is
ISO/TC 85/WG 3.
Current edition approved by ASTM June 1, 2004. Published May 15, 2005.
OriginallypublishedasASTME1939–98.LastpreviousASTMeditionE1939–98.
ThepresentInternationalStandardISO/ASTM51939:2005(E)isamajorrevisionof
AvailablefromtheInternationalCommissiononRadiationUnitsandMeasure-
the last previous edition ISO/ASTM 51939:2002:(E), which replaced ASTM E
ments, 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814 U.S.A.
1939–98.
Available from the National Blood Transfusion Service, East Anglian Blood
For referenced ASTM and ISO/ASTM standards, visit the ASTM website,
Transfusion Centre, Long Road, Cambridge, CB2 2PT United Kingdom.
www.astm.org, or contact ASTM Customer Service at service@astm.org. For
Available from the Office of Communication, Training and Manufacturers
Annual Book of ASTM Standards volume information, refer to the standard’s
Document Summary page on the ASTM website. Assistance (HFM-40), 1401 Rockville Pike, Rockville, MD 20852-1488, USA.
© ISO/ASTM International 2005 – All rights reserved
equivalent to the absorption of 1 joule per kilogram of the 3.1.10 dosimeter batch—quantity of dosimeters made from
specified material (1 Gy = 1 J/kg). The mathematical relation- a specific mass of material with uniform composition, fabri-
ship is the quotient of de by dm, where de is the mean cated in a single production run under controlled, consistent
incremental energy imparted by ionizing radiation to matter of conditions and having a unique identification code.
incremental mass dm (see ICRU 60).
3.1.11 dosimetry system—system used for determining ab-
sorbed dose, consisting of dosimeters, measurement instru-
D 5de¯ dm (1)
/
mentsandtheirassociatedreferencestandards,andprocedures
3.1.1.1 Discussion—The discontinued unit for absorbed
for the system’s use.
dose is the rad (1 rad = 100 erg/g = 0.01 Gy). Absorbed dose
3.1.12 installation qualification (IQ)—obtaining and docu-
is sometimes referred to simply as dose.
menting evidence that the irradiator, with all its associated
˙
3.1.2 absorbed-dose rate (D)—absorbed dose in a material
equipment and instrumentation, has been provided and in-
per incremental time interval, that is, the quotient of dD by dt.
stalled in accordance with specifications.
˙
D 5dD dt (2)
3.1.13 instrument traceability—abilitytodemonstratethata
/
–1
measurementinstrumenthasbeencalibratedatacceptabletime
Unit: Gy·s .
intervals against a national or international standard or against
3.1.3 absorbed-dose mapping—measurement of absorbed
asecondarystandardthathasbeencalibratedagainstanational
dose within product using dosimeters placed at specified
or international standard.
locations to produce a one, two, or three-dimensional distribu-
3.1.14 irradiator sample chamber—accessible enclosed
tion of absorbed dose, thus rendering a map of absorbed-dose
volume in which a sample or sample holder may be placed in
values.
the loading/unloading position of the irradiator (typically a
3.1.4 activity (A) (of an amount of radioactive nuclide in a
gamma cell) prior to irradiation, and which can be transported
particular energy state at a given time)—quotient of dN by dt,
by the sample positioning system to the irradiation position.
where dN is the expectation value of the number of spontane-
3.1.15 irradiator turntable—device used to rotate the irra-
ous nuclear transitions from that energy state in the time
diated sample during the irradiation process so as to improve
interval dt (see ICRU 60).
dose uniformity ratio.
A 5dN/dt (3)
3.1.15.1 Discussion—An irradiator turntable is often re-
−1
Unit: s
ferred to as a turntable. Some irradiator geometries, for
The special name for the unit of activity is the becquerel
example with a circular array of radiation sources surrounding
−1
(Bq). 1 Bq=1s .
the product, may not need a turntable.
3.1.4.1 Discussion—The former special unit of activity was
3.1.16 isodose curve—lines or surfaces of constant ab-
10 −1
the curie (Ci). 1 Ci = 3.7 3 10 s (exactly).
sorbed dose through a specified medium.
3.1.5 blood and blood components—include whole blood,
3.1.17 measurement quality assurance plan—documented
redcells,frozencells,plateletconcentrates,apheresisplatelets,
program for the measurement process that ensures on a
granulocyte concentrates, and fresh or frozen plasma.
continuing basis that the overall uncertainty meets the require-
3.1.5.1 Discussion—Enclosuresystemsforbloodandblood mentsofthespecificapplication.Thisplanrequirestraceability
components are commonly referred to as “bags.” The volume to, and consistency with, nationally or internationally recog-
of a typical blood bag is less than 0.5 L. Blood and blood nized standards.
components are often referred to as blood product.
3.1.18 measurement traceability—ability to demonstrate by
3.1.6 calibration—set of operations under specified condi- means of an unbroken chain of comparisons that a measure-
tions, which establishes the relationship between values indi- ment is in agreement within acceptable limits of uncertainty
cated by a measuring instrument or measuring system, and the with comparable nationally or internationally recognized stan-
corresponding values realised by standards traceable to a dards.
nationally or internationally recognized laboratory.
3.1.19 operational qualification (OQ)—obtaininganddocu-
3.1.7 canister—container, usually an aluminum or steel
mentingevidencethatinstalledequipmentandinstrumentation
cylinder, used to house the blood product, or blood-equivalent
operate within predetermined limits when used in accordance
product during the irradiation process.
with its operational procedures.
3.1.8 dose uniformity ratio—ratioofmaximumtominimum
3.1.20 performance qualification (PQ)—obtaining and
absorbed dose within the irradiated blood or blood product.
documentingevidencethattheequipmentandinstrumentation,
This concept is also referred to as the “max/min ratio.”
as installed and operated in accordance with operational
3.1.9 dosimeter—device that, when irradiated, exhibits a procedures, consistently perform according to predetermined
criteria and thereby yield product that meets specifications.
quantifiable change in some property of the device which can
be related to absorbed dose in a given material using appro-
3.1.21 radiation-sensitive indicator—material such as a
priate analytical instrumentation and techniques.
coated or impregnated adhesive-backed substrate, ink, coating
3.1.9.1 Discussion—Adosimetermustexhibitthereproduc- or other material which may be affixed to or printed on the
ible and quantifiable properties that allow it to be calibrated productandwhichundergoesavisualchangewhenexposedto
and compared to national standards. ionizing radiation.
© ISO/ASTM International 2005 – All rights reserved
3.1.21.1 Discussion—Radiation-sensitive indicators are of- 4. Significance and use
ten referred to as “indicators.” Radiation-sensitive indicators
4.1 The assurance that blood and blood components have
cannot be classified as a “label” under the U.S. FDA “Guide-
been properly irradiated is of crucial importance for patient
lines for the Uniform Labeling of Blood and Blood Products”
health. The irradiator operator must demonstrate by means of
(August, 1985). Indicators may be used to show that products
accurate absorbed-dose measurements on the product, or in
have been exposed to ionizing radiation. They can be used to
simulated product, that the specified absorbed dose has been
provide a visual and qualitative indication of radiation expo-
achieved throughout the product.
sure and can be used to distinguish between irradiated blood
4.2 Blood and blood components are irradiated at pre-
and blood components and non-irradiated blood and blood determined doses to inactivate viable lymphocytes to help
components. Indicators cannot be used as a substitute for preventtransfusion-inducedgraft-versus-hostdisease(GVHD)
proper dosimetry. in certain immunocompromised patients and those receiving
related-donor products (1, 2).
3.1.22 reference-standard dosimeter—dosimeter of high
4.3 Blood and blood components may be treated with
metrological quality used as a standard to provide measure-
137 60
ionizing radiation, such as gamma rays from Cs or Co
ments traceable to measurements made with primary-standard
sources, and from self-contained X-ray (bremsstrahlung) units
dosimeters.
and medical linear X-ray (bremsstrahlung) and electron accel-
3.1.23 routine dosimeter—dosimeter calibrated against a
erators used primarily for radiotherapy.
primary-, reference-, or transfer-standard dosimeter and used
4.3.1 The terms “gamma rays” and “gamma radiation” are
for routine absorbed-dose measurement.
used interchangeably, as are the terms “X-ray” and “X-
3.1.24 simulated product—material with radiation attenua-
radiation.”
tion and scattering properties similar to those of the product,
4.4 Blood irradiation specifications include a lower limit of
material or substance to be irradiated.
absorbeddose,andmayincludeanupperlimitorcentraltarget
3.1.24.1 Discussion—Simulated product is used during ir-
dose. For a given application, any of these values may be
radiator characterization as a substitute for the actual product,
prescribed by regulations that have been established on the
materialorsubstancetobeirradiated.Whenusedforabsorbed- basis of available scientific data. See 2.4.
dose mapping, simulated product is sometimes referred to as
4.5 For each blood irradiator, an absorbed-dose rate at a
phantom material. reference position within the canister is measured by the
manufacturer as part of acceptance testing using a reference-
3.1.25 transfer-standard dosimeter—dosimeter, often a
standard dosimetry system. That reference-standard measure-
reference-standard dosimeter, suitable for transport between
ment is used to calculate the timer setting required to deliver
different locations, used to compare absorbed-dose measure-
the specified absorbed dose to the center of the canister with
ments.
blood and blood components, or other reference position.
3.1.26 transit dose—absorbed dose delivered to a product
Either relative or absolute absorbed-dose measurements are
(or a dosimeter) while it travels between the non-irradiation
performed within the blood- or blood-equivalent volume for
position and the irradiation position, or in the case of a
determining the absorbed-dose distribution.Accurate radiation
movable source while the source moves into and out of its
dosimetryatareferencepositionwhichcouldbethepositionof
irradiation position.
the maximum absorbed dose (D ) or minimum absorbed
max
3.1.27 validation—establishment of documented evidence,
dose (D ) offers a quantitative, independent method to
min
which provides a high degree of assurance that a specified
monitor the radiation process.
process will consistently produce a product meeting its prede-
4.6 Dosimetry is part of a measurement quality assurance
termined specifications and quality attributes.
program that is applied to ensure that the radiation process
3.1.28 X-rays (bremsstrahlung)—common name for the
meets predetermined specifications (3).
short-wavelength electromagnetic radiation.The term includes
4.7 Absorbed-dose mapping is often performed using simu-
both broad-spectrum bremsstrahlung (emitted when an ener- lated product (for example, polystyrene is considered blood
getic electron is influenced by a strong electric or magnetic
equivalent for Cs photon energies).
field, such as that in the vicinity of an atomic nucleus) and the 4.8 Blood and blood components are usually chilled or
characteristic monoenergetic radiation (emitted when atomic frozen. Care should be taken, therefore, to ensure that the
electrons make transitions to more tightly bound states). dosimetersandradiation-sensitiveindicatorscanbeusedunder
such temperature conditions.
3.1.29 X-ray (bremsstrahlung) converter—device for gen-
4.9 Proper documentation and record keeping are critical
erating X-rays (bremsstrahlung) from an electron beam, con-
components of radiation processing. This standard does not
sisting of a target, means for cooling the target, and a
address this issue since the pertinent governing bodies set
supporting structure.
minimum requirements.
3.2 Definitions of other terms used in this standard that
pertain to radiation measurement and dosimetry may be found
inASTM Terminology E170. Definitions inASTM Terminol-
ogy E170 are compatible with ICRU 60; that document, 6
Theboldfacenumbersinparenthesesrefertothebibliographyattheendofthis
therefore, may be used as an alternative reference. standard.
© ISO/ASTM International 2005 – All rights reserved
4.10 Mostdosimetershavesignificantenergydependenceat spectrum, average electron beam current, and beam current
photon and electron energies less than 100 keV, so great care distribution on the target.
must be exercised when measuring absorbed dose in that
5.3.3 Spectrum filtration is used to reduce the low energy
energy range.
component of the X-rays, thus improving the dose uniformity.
5. Type of facilities and modes of operation used for
6. Radiation source characteristics
blood irradiation
6.1 The source of radiation used in a facility considered in
5.1 Self-Contained Blood Irradiators—Self-contained irra-
60 137
137 60
this practice consists of sealed Co or Cs sources that are
diators may utilize gamma rays from either Cs or Co (4),
typically linear rods arranged in one or more planar or
or low energy X-rays (bremsstrahlung). Units with radionu-
cylindrical arrays, X-rays (bremsstrahlung), or electrons.
clides house the radiation source in a protective lead shield (or
6.2 Cobalt-60emitsphotonswithenergiesofapproximately
other appropriate high atomic number material), and usually
1.17 and 1.33 MeV in nearly equal proportions. Cesium-137
have a mechanism to move the canister from the load/unload
produces photons with energies of approximately 0.662 MeV
position to the irradiation position. Typically, units with low-
(5).
energy X-rays (bremsstrahlung) require less shielding relative
60 137
6.3 The half-lives for Co and Cs are approximately
to units utilizing gamma rays. In some cases, irradiator
5.2708 years (6) and 30.07 years (7, 8), respectively.
turntables are used.
6.4 For gamma-ray sources, the only variation in the source
5.1.1 The most common method used to ensure a uniform
absorbed-dose distribution in the blood product is to rotate the output is the known reduction in the activity caused by
radioactive decay. The reduction in the source output and the
canister holding the blood product on an irradiator turntable in
front of the radiation source. required increase in the irradiation time to deliver the same
5.1.2 Asecondmethodistodistributeanumberofradiation dose may be calculated (see 9.3.4) or obtained from tables
sources in a circular array. The blood product is located at the provided by the irradiator manufacturer.
center of the array where the absorbed-dose distribution is
6.5 Direct-action electron accelerators, which employ dc or
relatively uniform. In this design, irradiator turntables would
pulsed high-voltage generators, typically produce electron
not normally be necessary.
energies up to 5 MeV. Indirect-action electron accelerators use
5.2 Teletherapy Equipment— Co equipment and linear
microwave or very high frequency (vhf) ac power to produce
accelerator teletherapy equipment (in electron or X-rays
electron energies typically from 5 MeV to 15 MeV.
(bremsstrahlung)mode)areusedprimarilyforthetreatmentof
6.6 The continuous energy spectrum of the X-rays
tumors. These units may also be used to irradiate blood and
(bremsstrahlung) ranges from approximately 40 keV up to the
bloodcomponents.Inbothtypesofequipment,theradiationis
maximum energy of the electrons incident on the X-ray
directed at the blood and blood components using a collimator
(bremsstrahlung) target (see ISO/ASTM Practice 51608).
that creates a well-defined beam of radiation. The blood
6.7 Regulations in some countries limit the maximum elec-
productisplacedintheradiationbeamandirradiatedstatically
tron energy to 10 MeV and photon energy to 5 MeV for
(that is, neither the source nor the blood product move relative
radiation treatment.
to one another during irradiation).
5.3 Electron Accelerator (Electron and X-ray (bremsstrahl-
7. Dosimetry systems
ung) Modes)—Accelerator-generated radiation is in the form
7.1 Description of Dosimeter Classes:
of electrons or X-rays (bremsstrahlung). Teletherapy accelera-
7.1.1 Dosimeters may be divided into four basic classes
tors can be used for this purpose. The blood product is placed
according to their relative quality and areas of application:
in the radiation beam and irradiated statically (that is, neither
primary-standard, reference-standard, transfer-standard, and
the source nor the blood product move relative to one another
routine dosimeters. ISO/ASTM Guide 51261 provides infor-
during irradiation).
mation about the selection of dosimetry systems for different
5.3.1 An electron accelerator emits high-energy electrons.
applications. All classes of dosimeters, except the primary
Thetwoprincipalbeamcharacteristicsaretheenergyspectrum
standards, require calibration before their use.
and the average beam current. The electron energy spectrum
7.1.1.1 Primary-Standard Dosimeters—Primary-standard
affects the variation of absorbed dose with depth in a given
dosimeters are established and maintained by national stan-
material, and the average beam current affects the absorbed-
dards laboratories for calibration of radiation environments
dose rate.
(fields) and other classes of dosimeters. The two most com-
5.3.2 An X-ray (bremsstrahlung) accelerator or generator
monly used primary-standard dosimeters are ionization cham-
emits short-wavelength electromagnetic radiation, which is
bers and calorimeters.
analogous to gamma radiation from radioactive sources. Al-
though their effects on irradiated materials are generally 7.1.1.2 Reference-Standard Dosimeters—Reference-
similar, these kinds of radiation differ in their energy spectra, standard dosimeters are used to calibrate radiation environ-
angular distribution, and dose rates. The physical characteris- ments and routine dosimeters. Reference-standard dosimeters
mayalsobeusedasroutinedosimeters.Examplesofreference-
tics of the X-rays (bremsstrahlung) field depend on the design
oftheX-rays(bremsstrahlung)converterandtheparametersof standard dosimeters, along with their useful dose ranges, are
given in ISO/ASTM Guide 51261 and Table 1.
theelectronbeamstrikingthetarget,thatis,theelectronenergy
© ISO/ASTM International 2005 – All rights reserved
TABLE 1 Examples of reference-standard dosimeters
Useful Absorbed-dose
Dosimeter Readout System Reference
Range (Gy)
Alanine EPR Spectrometer 1 to 10 ISO/ASTM 51607
Ethanol-Chlorobenzene solution Spectrophotometer, color titration, high 10 to 2 3 10 ISO/ASTM 51538
frequency conductivity
Fricke UV Spectrophotometer 20 to 400 ASTM E 1026
Ionization Chamber Electrometer Can be easily applied to the blood-irradiation (9)
A
Dose Range
A
In principle, an ion chamber can be used to make absolute absorbed-dose rate measurements at any dose rate. In the blood-irradiation dose-rate range (for example,
5 to 20 Gy/min), the ion chamber will perform satisfactorily if it has been calibrated within the applicable dose-rate range.
TABLE 2 Examples of transfer-standard dosimeters
Useful Absorbed-dose
Dosimeter Readout System Reference
Range (Gy)
Alanine EPR Spectrometer 1 to 10 ISO/ASTM 51607
Ethanol-Chlorobenzene solution Spectrophotometer, color titration, high 10 to 2 3 10 ISO/ASTM 51538
frequency conductivity
Fricke UV Spectrophotometer 20 to 400 ASTM E 1026
TABLE 3 Examples of routine dosimeters
Useful Absorbed-dose
Dosimeter Readout System Reference
Range (Gy)
-4 3
TLD (for example, LiF) Thermoluminescence reader 10 to 10 ISO/ASTM 51956
MOSFET semiconductor Electronic reader 1 to 200 (10, 11)
RadioChromic film UV/visible spectrophotometer, Transmission/Reflectance 10 to 10 ISO/ASTM 51275
Densitometer
Alanine EPR Spectrometer 1 to 10 ISO/ASTM 51607
Optical Waveguide Dosimeters Photometric means using dual wavelength photometry 1 to 2 3 10 ISO/ASTM 51310
Photo-Fluorescent Dosimeters (for example, LiF) Fluorimeter 10 to 3 3 10 ASTM E 2304
7.1.1.3 Transfer-Standard Dosimeters—Transfer-standard required to deliver the specified absorbed dose to the center of
dosimeters are specially selected dosimeters used for transfer- the blood and blood component volume, or other reference
ring absorbed-dose information from an accredited or national position.
standards laboratory to an irradiation facility in order to
7.2.1.1 Precise and accurate absorbed-dose measurements
establish traceability for that facility. These dosimeters should
are made in simulated product under routine-processing con-
be carefully used under conditions that are specified by the
ditions. The irradiation time to deliver the required absorbed
issuing laboratory. Transfer-standard dosimeters may be se-
dose can then be accurately determined.
lected from either reference-standard dosimeters or routine
NOTE 1—For reference standard dosimetry, the absorbed dose and
dosimeters taking into consideration the criteria listed in
absorbed-dose rate can be expressed in water or other material which has
ISO/ASTM Guide 51261 and Table 2.
similar absorption properties to that of blood and simulated-blood and
7.1.1.4 Routine Dosimeters—Routine dosimeters may be
blood components.
usedforradiationprocessqualitycontrol,dosemonitoringand
7.2.2 Quality Control and Routine Monitoring—Routine
dose mapping. Proper dosimetric techniques, including cali-
dosimeters may be used for quality control and routine
bration, shall be employed to ensure that measurements are
monitoring to help ensure that the product receives the desired
reliable and accurate. Examples of routine dosimeters, along
dose, and to identify unexpected changes in the process.
with their useful dose ranges, are given in ISO/ASTM Guide
7.2.2.1 Routinemeasurementsofabsorbeddosetotheblood
51261 and Table 3.
product will help ensure that the product has been treated with
7.2 Dosimeter Applications—In general, routine dosimeters
the minimum dose prescribed by the process, while not
are used to monitor the radiation process on a routine basis as
exceeding the maximum allowed dose.
an integral part of process control, and are used to perform
7.2.2.2 The absorbed dose may be measured at a reference
dose mapping to determine the absorbed-dose distribution
position (see 10.3.3). Accurate radiation dosimetry at a refer-
throughout the product or simulated product. The absorbed-
ence position, which could be the position of the maximum
dose rate at a specific location, used to determine the time
absorbeddose(D )orminimumabsorbeddose(D )offers
interval for the irradiation (or the timer setting), is determined
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a quantitative, independent method to monitor the radiation
using higher-quality reference-standard or transfer-standard
process.
dosimeters.
7.2.1 Timer Setting Calculations—Reference-standard do- 7.2.2.3 Routine dosimeters shall not be used to calculate or
simeter measurements are used to calculate the timer setting change the timer setting required to deliver the specified
© ISO/ASTM International 2005 – All rights reserved
absorbed dose to the product. For more information on routine 7.4 Factors That Affect the Response of Dosimeters:
monitoring, see Section 11. 7.4.1 Factors that affect the response of dosimeters, includ-
ingenvironmentalconditionsandvariationsofsuchconditions
NOTE 2—In the routine operation of a blood irradiator, absorbed-dose
within the processing facility, shall be known and their effect
measurements made on the product at regular intervals provide the
takenintoaccount(seeISO/ASTMGuide51261).Examplesof
operator and regulatory authorities with an independent quality control
routine dosimeters are listed inTable 3, and described in more
record for the process. When D has been set by the regulatory
min
authorities, the ability to measure that absorbed dose with proper detail in Annex A1.
statistical control is a critical requisite of Good Manufacturing Practices
7.4.2 The possible energy range for blood irradiation appli-
(GMPs).
cations is from 40 keV to 5 MeV for photons, and up to 10
MeV for electrons. Care must be taken, therefore, to calibrate
7.2.3 Absorbed-dose Mapping—Ideally, the radiation pro-
the dosimeter using typical energy ranges for routine use.
cess is designed to irradiate the blood product uniformly; in
reality,acertainvariationinabsorbeddosethroughtheproduct
8. Installation qualification
will exist. Absorbed-dose mapping is used to determine the
magnitude and locations of D and D for a given set of
8.1 Objective—The purpose of an installation qualification
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operating parameters (for example, timer setting, product
program is to obtain and document evidence that the irradiator
loading configuration). For self-contained dry storage irradia-
and measurement instruments have been delivered and in-
tors, the blood product may be relatively close to the radiation
stalled in accordance with their specifications. Installation
source, resulting in pronounced absorbed-dose gradients near
qualification includes documentation of the irradiator equip-
the periphery of the blood or blood-component volume. It is
ment and measurement instruments; establishment of testing,
important, therefore, to choose a dosimeter with adequate
operation and calibration procedures for their use; and verifi-
resolution to detect these gradients. The routine dosimetry
cation that the installed irradiator equipment and measurement
system may be used for relative or absolute absorbed-dose
instruments operate according to specification.
measurementsorformappingtheabsorbed-dosedistributionin
NOTE 3—Table A2.1 gives some recommended steps in the following
the blood-irradiation volume. For more information on dose
areas: installation qualification, operational qualification, performance
mapping, see 9.3.2 and 10.3.
qualification, and routine product processing. The recommended steps in
7.3 Calibration of Dosimetry Systems:
Table A2.1 are not meant to be exhaustive.
7.3.1 Prior to use, the dosimetry system (consisting of a
8.2 Equipment Documentation—Establishanddocumentan
specific batch of dosimeters and specific measurement instru-
installation qualification program that includes descriptions of
ments) shall be calibrated in accordance with the user’s
the instrumentation and equipment and measurement instru-
documented procedure that specifies details of the calibration
ments installed at the facility. This documentation shall be
process and quality assurance requirements. This calibration
retained for the life of the facility. At a minimum, it shall
process shall be repeated at regular intervals to ensure that the
include:
accuracy of the absorbed-dose measurement is maintained
8.2.1 A description of the irradiator’s specifications, char-
within required limits. Calibration methods are described in
acteristics and parameters, including any modifications made
ISO/ASTM Guide 51261.
during or after installation,
7.3.2 Irradiationisacriticalcomponentofthecalibrationof
8.2.2 A description of the location of the irradiator within
the dosimetry system.
the operator’s premises, including its relation to any means
7.3.3 Calibration Irradiation of Reference-Standard or
providedforsegregatingunirradiatedfromirradiatedproducts,
Transfer-Standard Dosimeters—Calibration irradiations shall
8.2.3 Operating instructions and standard operating proce-
be performed at an accredited calibration laboratory, or in-
dures for the irradiator and associated measurement instru-
house calibration facility meeting the requirements of ISO/
ments,
ASTM Practice 51400, that provides an absorbed dose (or
8.2.4 Description of the construction and operation of the
absorbed-doserate)havingmeasurementtraceabilitytonation-
product handling system,
ally or internationally recognized standards.
8.2.5 Licensing and safety documents and procedures, in-
7.3.4 Calibration Irradiation of Routine Dosimeters—
cluding those required by regulatory and occupational health
Calibration irradiations may be performed per 7.3.3, or at an
and safety agencies,
irradiationfacilitytogetherwithreference-ortransfer-standard
8.2.6 A description of a calibration program to ensure that
dosimeters that have measurement traceability to nationally or
all processing equipment that may influence absorbed-dose
internationally recognized standards. This clause also applies
delivery is calibrated periodically (for example, the reset timer
whenreference-standarddosimetersareusedasroutinedosim-
mechanism on a gamma irradiator), and
eters.
8.2.7 Descriptions, operating procedures, and calibration
7.3.5 Measurement Instrument Calibration and Perfor- proceduresforassociatedmeasurementinstrumentsorsystems
mance Verification—Forthecalibrationoftheinstruments,and (such as those used for dosimetry).
fortheverificationofinstrumentperformancebetweencalibra- 8.3 Equipment Testing and Calibration—Testallprocessing
equipment and instrumentation that may influence absorbed
tions, see ISO/ASTM Guide 51261, the corresponding ISO/
ASTM or ASTM standard for the dosimetry system, and/or dose in order to verify satisfactory operation of the irradiator
instrument-specific operating manuals. within the design specifications.
© ISO/ASTM International 2005 – All rights reserved
8.3.1 Implement a documented calibration program to en- rate at a reference position within simulated product following
sure that all processing equipment and instrumentation that installation of (or, in the case of some self-contained units,
may influence absorbed-dose delivery are calibrated periodi- before shipping) the irradiator.
cally.
9.3.1.2 Reference- or transfer-standard measurement of
8.3.2 Ifanymodificationorchangeismadetotheirradiator absorbed-dose rate at a reference position should be repeated
equipment or measurement instruments during the installation
periodically (for example, every two years for a gamma
qualification phase, they shall be re-tested. facility) and following any changes to the source, geometry, or
8.4 For self-contained irradiators, installation qualification
other irradiator parameter that could affect absorbed-dose rate.
may begin prior to the shipment of the irradiator to the
NOTE 4—Tothedegreepossible,subsequentre-calibrationsofdoserate
customer’s site.
should be performed under similar conditions to allow direct comparison
amongst test results. Results obtained when re-calibrating an irradiator
9. Operational qualification
should agree with results of previous calibrations, once source decay (if
9.1 Objective—The purpose of operational qualification of
applicable) or other known factors that may affect dose are taken into
anirradiationfacilityistoestablishbaselinedataforevaluating
account.Unexplaineddiscrepanciesthatarebeyondthelimitofcombined
irradiator effectiveness, predictability, and reproducibility for uncertainty for the two procedures should be investigated, as they could
indicate problems with the dosimetry or the operation of the irradiator.
the range of conditions of operation for key processing
NOTE 5—When an irradiator’s absorbed-dose rate is measured, it is
parameters that affect absorbed dose in the product.As part of
convenient to calibrate the facility’s routine dosimetry system concur-
this process, dosimetry may be performed to: (1) establish
rentlyper7.3.ISO/ASTMGuide51261providesguidelinesonprocedures
relationships between the absorbed dose for a reproducible
and numbers of sets of dosimeters needed.
geometry and the operating parameters of the irradiator, (2)
9.3.2 Dose Mapping—Ideally, the irradiation process is
measure absorbed-dose distributions in blood-equivalent ma-
terial and other reference materials, (3) characterize absorbed- designedtoirradiateblooduniformlythroughouttheirradiated
volume;inreality,acertainvariationinabsorbed-dosethrough
dose variations when irradiator and processing parameters
fluctuate statistically through normal operations, and (4) mea- the product will exist. The irradiator characterization process
includes mapping the absorbed-dose distributions for samples
sure the absorbed-dose rate at a reference position within the
canister filled with blood or simulated product. of blood or simulated product, and identifying the magnitudes
and locations D and D within the samples. Dosimetry
9.1.1 For self-contained irradiators, operational qualifica-
max min
tion may begin prior to the shipment of the irradiator to the data from previously characterized irradiators of the same
design or theoretical calculations may provide useful informa-
customer’s site. As part of release-for-shipment criteria, the
irradiator manufacturer may perform absorbed-dose mapping tionfordeterminingthenumberandlocationsofdosimetersets
needed for this characterization process.
toestablishbaselinedata.Aftertheunitisinstalledattheuser’s
site, operational qualification is performed as part of the user’s 9.3.2.1 Map the absorbed-dose distribution by placing do-
quality assurance plan (see ISO/ASTM 52116). simeters throughout the actual or simulated product. Select
9.2 Dosimetry Systems—Calibrate the routine dosimetry placement patterns that can identify the locations of D and
max
system to be used at the facility as discussed in 7.3. D .
min
9.3 Irradiator Characterization—The absorbed dose re-
NOTE 6—In the case of static irradiations (such as when the product is
ceived by any portion of
...