IEC 60601-2-11:1997/AMD1:2004

INTERNATIONAL IEC
STANDARD 60601-2-11
AMENDMENT 1
2004-07
Amendment 1
Medical electrical equipment –
Part 2-11:
Particular requirements for the safety
of gamma beam therapy equipment

© IEC 2004 Droits de reproduction réservés ⎯ Copyright - all rights reserved
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For price, see current catalogue

– 2 – 60601-2-11 Amend. 1 © IEC:2004(E)

FOREWORD
This amendment has been prepared by subcommittee 62C: Equipment for radiotherapy,

nuclear medicine and radiation dosimetry, of IEC technical committee 62: Electrical equipment

in medical practice.
The text of this amendment is based on the following documents:

FDIS Report on voting
62C/372/FDIS 62C/375/RVD
Full information on the voting for the approval of this amendment can be found in the report
on voting indicated in the above table.
The committee has decided that the contents of this amendment and the base publication will
remain unchanged until the maintenance result date indicated on the IEC web site under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
___________
INTRODUCTION
This amendment is applicable to equipment for multi-source STEREOTACTIC treatment including
radiosurgery and RADIOTHERAPY (MSSR). STEREOTAXIS is defined as a method for locating
points within the human body using an external three-dimensional frame of reference.
•••• Though multi-source STEREOTACTIC RADIOTHERAPY equipment is included in the scope of
this part of IEC 60601, some requirements and definitions have turned out to be
inadequate for current equipment of this very special type. This amendment introduces
new terminology in this area.
Modifications to test principles or procedures have not been considered.

Page 13
1.1 Scope
bb)
Add, after the existing text , the following new paragraph:
This standard applies also to multi-source STEREOTACTIC RADIOTHERAPY equipment used to
IRRADIATE a single ISOCENTRE simultaneously with more than one SEALED RADIOACTIVE SOURCE.
The sources may be stationary or moving.

60601-2-11 Amend. 1 © IEC:2004(E) – 3 –

Page 17
2 Terminology and definitions
Replace the existing text of definitions 2.101 and 2.102 by the following:

2.101
BEAM OFF
condition in which the RADIATION SOURCES are fully shielded, and are also in a position in

which they can be secured
2.102
BEAM ON
condition in which the RADIATION SOURCES are fully exposed for RADIOTHERAPY
Add, on page 19, the following new definitions:
2.122
HELMET
three-dimensional multi-source ISOCENTRIC BEAM LIMITING SYSTEM (MIBLS) used in MSSR for
treatment of a human head
2.123
REPOSITIONING
movement and adjustment of the STEREOTACTIC frame with respect to the MIBLS to alter the
intended treatment volume
2.124
REPOSITIONING POINT
retracted position of the MIBLS where REPOSITIONING of the frame is possible
2.125
REPOSITIONING TIME
added time the equipment needs to move from the BEAM ON condition to the REPOSITIONING
POINT, to achieve REPOSITIONING and to return from the REPOSITIONING POINT to the BEAM ON
condition
2.126
STEREOTAXIS
STEREOTACTIC
method for locating points within the human body using an external, three-dimensional frame
of reference
2.127
TRANSITION TIME
time between when the SHUTTER is opened and the MIBLS or SOURCE CARRIER is in the
TREATMENT position
2.128
TRANSITION RADIATION
dose received during the TRANSITION TIME

– 4 – 60601-2-11 Amend. 1 © IEC:2004(E)

Page 23
5 Classification
5.2 According to the degree of protection against electric shock:

Replace the existing text by the following:

EQUIPMENT within the scope of this standard shall be TYPE B EQUIPMENT except for MSSR,

which shall be TYPE B EQUIPMENT or TYPE BF EQUIPMENT.

Page 25
6.3 Marking of controls and instruments
aa)
1) Add the following sentence:
This applies in case of MSSR, with the exception of PATIENT SUPPORT and when needed for
patient treatment.
2) Add the following sentence:
For MSSR: IEC 61217 shall be used where applicable.
3) Add the following sentence:
This requirement is not applicable for MSSR.
4) Add the following sentence:
This requirement is not applicable for MSSR.
Page 27
6.8.2 INSTRUCTIONS FOR USE
aa)
10) Add, on page 29, the following sentence:
This requirement is not applicable for MSSR;

60601-2-11 Amend. 1 © IEC:2004(E) – 5 –

Page 29
6.8.3 Technical description
a) General
aa) To assist the USER’S RADIOLOGICAL PROTECTION adviser, the following data shall be

provided:
c) Add the following sentence:

In case of MSSR the maximum ABSORBED DOSE RATE for the maximum cross-
section of the RADIATION BEAM at the ISOCENTRE or at the centre of the common
volume defined by all the RADIATION BEAMS for each RADIONUCLIDE for which the
requirements of this standard are met.
d) Add the following sentence:
This item is not applicable for MSSR.
Add the following new item:
h) Matrix measurement points for RADIATION levels for BEAM ON and BEAM OFF
conditions at the floor level and at 0,5, 1,0, 1,5 and 2,0 m above the floor level in
MSSR (see Figure 105).
Page 37
22.4 Replacement:
a) Add the following note after the first paragraph:
NOTE In case of MSSR, operator action on two switches shall be required to move the PATIENT SUPPORT into the
TREATMENT position. However in the case when the TREATMENT is completed or when a single fault condition
occurs, no manual activation shall be needed and therefore no switch is used.
Replace the second sentence of the second paragraph by the following new sentence:
At least one set of switches shall be located so as to require the presence of the OPERATOR

close to the PATIENT, except for MSSR, to observe the moving parts of the equipment.
Add the following new items:
f) An interlock or mechanical provision shall be provided to prevent a patient being hit or
trapped by the SHUTTERS in MSSR.
g) Means shall be provided to release a patient mechanically if the PATIENT SUPPORT fails to
move from the BEAM ON condition in MSSR.

– 6 – 60601-2-11 Amend. 1 © IEC:2004(E)

Page 43
29.1.1.2
Replace the first paragraph by the following:

The duration of the transition from the BEAM OFF condition to the BEAM ON condition together

with the return movement shall not exceed 5 s or in the case of MSSR 60 s.

Add the following note after the first paragraph:

NOTE This timing in MSSR is based on the mechanical motion of the PATIENT SUPPORT system from the BEAM OFF
to the BEAM ON position when the SHU
...