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MINUTES –tcon
Brachy Therapy Group
of the DICOM Working Group Seven (Radiation Therapy)
of the DICOM Standards Committee
November 6, 2013
Present
Representing
Joni Bask
Walter Bosch
Ulrich Busch
Bruce Curran
Henk van Dijken
Milena Donato
Varian Medical System
ATC
Varian Medical System
AAPM
Elekta / Nucletron
Varian Medical System
Michael Fabrizio
Wenzheng Feng
Varian Medical System
Columbia University Medical Center
New York-Presbyterian Hospital
Kevin Spetz
Toni Taiminen
Varian Medical Systems
Varian Medical Systems
Stephen Vastagh
DICOM General Secretary / MITA
Not Present
Rob van der Laarse
Representing
ESTRO Braphyqs Working Group
Paul Jacobs
Thomas Osche
MIMVista Corp.
Eckert&Ziegler BEBIG
DICOM Brachy Group of WG-07
2013-11-06
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Presiding Officer
Secretary
Henk van Dijken, Chair
Stephen Vastagh, M ITA
1. Opening




The Chair called the meeting to order at 09.00 USA Eastern Time.
The secretary reviewed the antitrust rules.
The Minutes of the last t-con were approved.
The Agenda was reviewed and approved.
2. Review of Outreach to Increase Participation in Group
H. Van Dijken reported that he is continuing to follow-up with emails with the companies he met
at the AAPM Conference. S. Vastagh noted that the active participation of users, like Bruce
Curran, Walter Bosch, and Wenzheng Feng is extremely important; he encouraged the members
to continue to invite clinical practitioners to actively participate in the Group.
3. Transfer of Empty Channel Definitions
cp_BrachyZeroControlPoints.doc
(complete title: RT Brachy Applications Setups Module: Allow zero control points
T. Taiminen reported that as per the homework he discussed the current use and need for the
empty channel definitions. He confirmed that there are empty channels, especially with
multi-channel prostate and breast cases
W. Bosch suggested adding a type 3 sequence.
K. Spetz suggested another use case for multi systems.
W. Feng noted that in some cases the software allows several channels but the applicator
only has three physical channels.
A long technical discussion followed which included :
 Reviewing how channels are identified currently
DICOM Brachy Group of WG-07
2013-11-06
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
Channel number may not be the best way to identify channels because the re-use
may have other negative effects.
J. Bask suggested, at the end of the discussion, that there may not be a pressing clinical
need for this definition. There was a consensus that this issue should be addressed in the
2nd Generation of the Standard. (The Brachy object for the 2nd Generation is not yet
defined.)
CONCLUSION:
ACTION:
It was concluded that because no clinical need has been identified, the CP
will not be pursued. There are workarounds in the 1st Generation of the
Brachy object. U. Busch suggested to continue considering whether to
elaborate on the identification of the identification of the physical channel
numbers.
U. Busch noted that the Brachy Group should be collecting the items to be
covered in the Brachy object of the 2nd Generation.
HOMEWORK for all members: (1) check how the identification of physical channels is
accomplished currently in different plans and systems. (2) how to standardize the identification.
4. The Source Model ID is missing from the Source Model Information
cp_SourceModelID.doc
(complete title: RT Brachy Applications Setups Module: Source Model ID is missing)
At the last meeting it was discussed that there are not enough attributes to fully determine
what kind of source was actually used, especially source construction. Need to be able to
unambiguously define the source, perhaps using a predefined list.
At this meeting it was further discussed that the Source Model ID its purpose is to indicate
the source package used (pre-defined list) and the Source Serial Number can be included as a
vendor specific ID. In this way the matching of actual dosimetric source is not ambiguous
anymore.
HOMEWORK:
Toni T. will turn the CP outline into formal tables and attribute tables.
Follow current CP template in
ftp://medical.nema.org/medical/Dicom/Template/CP_Template-2011.doc
DICOM Brachy Group of WG-07
2013-11-06
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5. Manual Loaded Applicator may require Source Definition
cp_MultiSourceChannel.doc
(complete title: RT Brachy Applications Setups Module: Channel cannot contain multiple
radioactive sources)
At the last meeting it was discussed that there is the need to use multiple source definitions,
which is not allowed in the standard, but common practice when using manual loading
applicators. There was no time to discuss further this CP, at this meeting.
Next step: The Group will further discuss this CP.
6. Request for Richer Description of Dose Calculation Approach
Issue: At the last meeting B. Curran proposed this topic noting that this is a request by users;
the dose calculation model used should be described as part of the plan.
B. Curran noted that this is probably a 2nd Generation issue. A recent AAPM Task Group
186 Report (Brachy QA) is relevant. It was noted that this is L. Beaulieu’s Task Group.
It was noted that this will be on the upcoming WG-07 Agenda with the goal of developing a
solution (i.e. expand the defined terms to be consistent across manufacturers, add descriptors,
extensions.) This has has applicability to 1st and 2nd Generations of the Standard.
7. New Business
New issues proposed by Luc Beaulieu, representative AAPM Brachy Group:

DICOM-RT object reference frame. It seems for example that Oncentra (Elekta) and
BrachyVision (Varian) do not use the same definition for the coordinate system. These create
issue when importing source positions or applicators. Since our goal is to create reference
DICOM-RT sets, this is an important issue when dealing with multiple vendors.
Discussion:
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2013-11-06
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L. Beaulieu was not present. B. Curran opined that this is not a DICOM issue, rather an
application issue such as those dealt with by IHE-RO (a profile may be suggested to test
whether the systems are transferring this information. Meanwhile the review of DICOM
conformance statements was recommended.

Source orientation, in particular for LDR seed implants, are not included in the DICOM-RT
std.
Discussion:
The solution appears to be again that IHE-RO creates a conformance test.

As some point material definition, on a voxel-basis might be required for advanced dose
calculation. Right now this is done prior to dose calculation by the end users but that
information does not follow in the DICOM-RT export/import. I suppose that this issue might
be seen as similar to the CT calibration curve not being included in the DICOM-RT set.
Discussion:
It was concluded that voxel-based segmentation is included in the 2nd Generation Standard.
No corrections were recommended for the current 1st Generation of the Standard.
ACTION:
L. Beaulieu will be invited to the next t-con.
8. Next Meetings and Tcons

Wednesday, Dec 11, 2013 09.00 -10.30 USA Eastern Time

Wednesday, Jan 15, 2013 09.00 -10.30 USA Eastern Time
9. Adjournment
The t-con was adjourned at 10.45 am
Reported by:
Stephen Vastagh, Secretary
Reviewed by legal counsel: CRS 2013-11-06
DICOM Brachy Group of WG-07
2013-11-06
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