SIST EN ISO 16645:2019

SLOVENSKI STANDARD
oSIST prEN ISO 16645:2019
01-januar-2019
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Radiological protection - Medical electron accelerators - Requirements and
recommendations for shielding design and evaluation (ISO 16645:2016)
Strahlenschutz - Medizinische Elektronenbeschleuniger-Anlagen - Anforderungen und
Empfehlungen an die Ausführung der Abschirmung und deren Bewertung (ISO
16645:2016)
Radioprotection - Accélérateurs médicaux d'électrons - Exigences et recommandations
pour la conception et l'évaluation du blindage (ISO 16645:2016)
Ta slovenski standard je istoveten z: prEN ISO 16645
ICS:
11.040.99 Druga medicinska oprema Other medical equipment
13.280 Varstvo pred sevanjem Radiation protection
oSIST prEN ISO 16645:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 16645:2019

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oSIST prEN ISO 16645:2019
INTERNATIONAL ISO
STANDARD 16645
First edition
2016-10-01
Corrected version
2016-11-15
Radiological protection — Medical
electron accelerators — Requirements
and recommendations for shielding
design and evaluation
Radioprotection — Accélérateurs médicaux d’électrons — Exigences
et recommandations pour la conception et l’évaluation du blindage
Reference number
ISO 16645:2016(E)
©
ISO 2016

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oSIST prEN ISO 16645:2019
ISO 16645:2016(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
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CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2016 – All rights reserved

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oSIST prEN ISO 16645:2019
ISO 16645:2016(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Quantities . 1
3.2 Definitions . 4
4 Shielding design goals and other design criteria . 6
4.1 Shielding design goals. 6
4.2 Shielding design assumptions . 7
5 Role of the manufacturers, of the radiation protection officer or qualified expert
and interactions between stakeholders . 8
5.1 General . 8
5.2 Linear accelerator manufacturer . 8
5.3 Shielding material vendor . 9
5.4 Architectural firm/general contractor .10
5.5 Radiation protection officer or qualified expert .10
5.6 The licensee .11
6 Radiation fields around a linear electron accelerator .11
6.1 General .11
6.2 X-ray radiation .11
6.2.1 Primary X-ray beam .11
6.2.2 Primary electron beam bremsstrahlung .12
6.2.3 Secondary X-ray radiation .12
6.2.4 Tertiary X-ray radiation.13
6.3 Neutron radiation .13
6.3.1 General.13
6.3.2 Direct neutron radiation .14
6.3.3 Scattered and thermal neutron radiation.14
6.3.4 Primary barrier neutron radiation .15
6.4 γ radiation .15
6.4.1 General.15
6.4.2 Maze γ radiation . .15
6.4.3 Door γ radiation.15
6.4.4 Primary barrier γ radiation .15
6.4.5 Air γ radiation .16
7 Shielding materials and transmission values .16
8 General formalism for shielding calculation .18
9 Shielding calculation for conventional devices .20
9.1 General .20
9.2 Primary barriers .20
9.2.1 Radiation components .20
9.2.2 Barrier with a unique material .21
9.2.3 Barrier with multiple layers . .21
9.3 Secondary barriers .22
9.3.1 Radiation components .22
9.3.2 Barrier with a unique material .23
9.3.3 Barriers with multiple layers .24
10 Doors and mazes .24
10.1 General .24
© ISO 2016 – All rights reserved iii

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oSIST prEN ISO 16645:2019
ISO 16645:2016(E)

10.2 Radiation components .25
10.3 Standard maze .25
10.3.1 Maze X-ray scatter calculations .25
10.3.2 X-ray direct Leakage . . .30
10.3.3 Maze neutron and capture gamma calculations .31
10.4 Two legged maze .33
10.5 No maze - Direct-shielded doors .34
10.5.1 General.34
10.5.2 Shielding at the far side of a direct-shielded door entrance .35
10.5.3 Shielding at the near side of a direct-shielded door entrance .37
10.6 No door at maze entrance .39
10.7 Door Calculations .40
10.7.1 General.40
10.7.2 Maze door calculations .40
10.7.3 Direct Shielded Door Calculations .41
11 Shielding calculations for special devices .41
11.1 General .41
11.2 Robotic arm accelerator .41
11.3 Helical intensity modulated radiotherapy .42
11.4 Dedicated device for intra operative radiotherapy with electrons .42
12 Ducts .43
12.1 Duct impact on radiation protection .43
12.2 Recommended location and geometry .43
12.3 Additional shielding .44
12.3.1 General.44
12.3.2 Neutron and capture gamma radiation passing through the interior of the
shielded duct .44
12.3.3 X scattered radiation passing through the interior of the shielded duct .45
12.3.4 Scattered radiation passing through the walls of the duct shielding .46
12.3.5 Dose equivalent at HVAC duct exterior opening .46
13 Special considerations .46
13.1 Skyshine .46
13.1.1 General.46
13.1.2 X-ray skyshine radiation .46
13.1.3 Neutron skyshine radiation .48
13.2 Groundshine radiations .49
13.3 Joints and junctions .49
14 Shielding evaluation (experimental verification) .49
14.1 General .49
14.2 Measuring equipment and methodology .50
14.3 Evaluation .50
15 Indication, warning signs, interlocks .52
Annex A (informative) Tenth value layers for the most common shielding materials .53
Annex B (informative) Supporting data for shielding calculations .66
Annex C (informative) Example of calculation for conventional device and standard maze .68
Bibliography .75
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oSIST prEN ISO 16645:2019
ISO 16645:2016(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directives
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received. www.iso.org/patents
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT), see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 85, Nuclear energy, nuclear technologies, and
radiological protection, Subcommittee SC 2, Radiological protection.
This corrected version of ISO 16645:2016 incorporates the correction of Tables A.9 and C.6.
© ISO 2016 – All rights reserved v

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oSIST prEN ISO 16645:2019
ISO 16645:2016(E)

Introduction
Radiotherapy uses external beam radiation to kill cancer cells and shrink tumours. The use of electron
linear accelerators to administer external beam radiation has spread during recent decades and is now
common throughout the world. These accelerators deliver high energy electron and photon beams with
increasingly high dose rates. Although the use of radiotherapy is well established, irradiation techniques
have continued to evolve and are becoming increasingly complex. Examples include modulation of beam
intensity, availability of high dose rate modes, arctherapy, helical intensity modulated radiotherapy,
robotic arm accelerators, and dedicated devices for intra-operative radiotherapy. The shielding design
of treatment rooms has been evolving with these changes. The higher radiation workload associated
with most of these techniques can impact the shielding materials used. The irradiation technique can
also impact the geometry to be considered in the shielding calculations.
IEC 60601-2-1 relates to the design and the construction of the accelerators in order to ensure the
[1] [2][3]
safety of their operation . In addition, several national or international (IAEA Safety Reports

Series Report No. 47, 2006) reports propose recommendations concerning the installation and the
exploitation of these accelerators, the safety devices, the design and the calculation of protections, the
[4]
radiological control and monitoring. National standards have been established in certain countries
[5]
. Moreover national regulations impose particular rules of protection against radiation, in particular
relating to the definition of the controlled areas and the calculation of shielding.
Taking into account the developments of new irradiation techniques and of new designs of treatment
room facilities on the one hand, and the variety of guides or normative documents on the other hand,
it appeared judicious to establish an international standard to be used as a general framework. This
standard is intended to be complementary to the other international standards (IEC and IAEA).
The following items are discussed in the standard:
— types of accelerators: conventional accelerators with and without flattening filter (FF and FFF
operating modes), devices for helical intensity modulated radiotherapy and robotic arm accelerator,
dedicated machines for intra-operative radiotherapy;
— radiation fields: electrons, X photons and neutrons (direct, scattered, leakage), neutron capture
gamma rays;
— Treatment room geometry: maze without and with door, no maze with direct door;
— materials of protection: concrete (ordinary or high density), metals, laminated barriers (concrete
and metal), hydrogenated materials, earth and others;
— design of the radiotherapy facility:
— calculation methods of the shielding, including neutrons, various types of installations and shielding
geometries;
— evaluation of the impact of the maze and calculation of the protection of the entrance door;
— evaluation of the impact of the ducts (ventilation and air-conditioning, high voltage and fluids) and
additional protections;
— shielding design assumption and goals;
— Radiation survey of the completed installation to ensure national requirements have been met and
the shielding and design is fit for purpose after installation of the accelerator.
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oSIST prEN ISO 16645:2019
INTERNATIONAL STANDARD ISO 16645:2016(E)
Radiological protection — Medical electron accelerators —
Requirements and recommendations for shielding design
and evaluation
1 Scope
This International Standard is applicable to medical electron linear accelerators i.e. linear accelerators
with nominal energies of the beam ranging from 4 MV to 30 MV, including particular installations
such as robotic arm, helical intensity modulated radiotherapy devices and dedicated devices for intra
operative radiotherapy (IORT) with electrons.
The cyclotrons and the synchrotrons used for hadrontherapy are not considered.
The radiation protection requirements and recommendations given in this International Standard
cover the aspects relating to regulations, shielding design goals and other design criteria, role of
the manufacturers, of the radiation protection officer or qualified expert and interactions between
stakeholders, radiations around a linear accelerator, shielding for conventional and special devices
(including shielding materials and transmission values, calculations for various treatment room
configurations, duct impact on radiation protection) and the radiological monitoring (measurements).
NOTE 1 Annex A provides transmission values for the most common shielding materials.
NOTE 2 Annex B provides supporting data for shielding calculation.
NOTE 3 Annex C provides an example of calculation for conventional device and standard maze.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
IEC 60976, Medical electrical equipment — Medical electron accelerators — Functional performance
characteristics
IAEA Safety Reports Series Report No. 47, Radiation protection in the Design of Radiotherapy
Facilities (2006)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60976 and the following apply.
3.1 Quantities
3.1.1
absorbed dose
D
quotient of dε by dm, where dε is the mean energy imparted to matter of mass dm thus
dε
D =
dm
© ISO 2016 – All rights reserved 1

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oSIST prEN ISO 16645:2019
ISO 16645:2016(E)

Note 1 to entry: In this document, the absorbed dose is defined for radiation produced by a linear accelerator at a
specific location: the absorbed dose to water at the isocentre (at 1 m from the source for conventional devices) at a
reference depth in water in electron equilibrium conditions (for example at the depth of maximum absorbed dose).
−1
Note 2 to entry: The unit of absorbed dose is joule per kilogram (J·kg ), and its special name is gray (Gy).
[6]
[SOURCE: ISO 12749-2:2013, 4.1.6.7]
3.1.2
absorbed dose rate
output rate
DR
o
dose absorbed per unit of time
Note 1 to entry: In this International Standard, in the absence of specific indication, the absorbed dose rate is
defined for radiation produced by a linear accelerator at a specific location: the absorbed dose rate to water at the
isocentre (at 1 m from the source for conventional devices) at a reference depth in water in electron equilibrium
conditions (for example at the depth of maximum absorbed dose).
−1
Note 2 to entry: The unit of absorbed dose rate is gray per second (Gy·s ). The usual unit for medical accelerators
−1
is gray per hour (Gy·h ).
3.1.3
dose equivalent
H
product of D and Q at a point in tissue, where D is the absorbed dose (3.1.1) and Q is the quality factor
for the specific radiation at this point, thus: H = D × Q
−1
Note 1 to entry: The unit of dose equivalent is joule per kilogram (J·kg ), and its special name is sievert (Sv).
[6]
[SOURCE: ISO 12749-2:2013, 4.1.6.8]
3.1.4
IMRT ratio
C
I
ratio of the average monitor unit per unit prescribed absorbed dose needed for IMRT (MU ) and the
IMRT
monitor unit per unit absorbed dose for conventional treatment (MU )
conv
MU
IMRT
C =
I
MU
CONV
3.1.5
instantaneous dose-equivalent rate
IDR
–1
“ambient/personal” dose-equivalent rate (Sv·h ) as measured with the linear accelerator operating at
–1
the absorbed dose rate DR (Gy·h )
o
Note 1 to entry: This is the direct reading of the ratemeter that gives a stable reading in
...