ON THE DEVELOPMENT OFTARGET VOLUME GUIDELINES
IN EXTREMITY SARCOMAS; WORK IN PROGRESS BY A
TRANSATLANTIC RADIATION-ONCOLOGISTSTASK FORCE.
Rick HaasNKI – AVL Amsterdam
TRANSATLANTIC RADIATION-ONCOLOGISTS TASK FORCE
R.L.M. Haas, chair The Netherlands Cancer Institute, Amsterdam.J. Duppen research programmer
B. O’Sullivan Princess Margaret Hospital, Toronto, Canada.Th. F. DeLaney Massachusetts General Hospital, Boston, USA. C. Le Pechoux Institute Gustav Roussy, Paris, France.P. Olmi Instituto di Tumori, Milan, Italy.R. Keus Arnhem’s Radiation Oncology Institute, Arnhem,
The Netherlands
Introduction
For many irradiation regimens guidelines on the drawing of target volumes (TV) are available.
Introduction; head and neck
For many irradiation regimens guidelines on the drawing of target volumes (TV) are available.
Proposal for the delineation of the nodal CTV in the node-positive and the post-operative neck Vincent Grégoire; Radiotherapy and Oncology 2006; 79 : 15-20.
Introduction; pelvic nodes in gynecology
For many irradiation regimens guidelines on the drawing of target volumes (TV) are available.
Target volume definition for intensity modulated whole pelvic radiotherapyJ. Staffurth; ASCO 2005 www.asco.org
Introduction
For many irradiation regimens guidelines on the drawing of target volumes (TV) are available.
Guidelines in extremity sarcomas (ES) are lacking up to now.
Introduction
For many irradiation regimens guidelines on the drawing of target volumes (TV) are available.
Guidelines in extremity sarcomas (ES) are lacking up to now.
The EORTC develops a new phase III trial on pre- versus postoperative irradiation in ES patients.
EORTC 62064 / 22064
Introduction
For many irradiation regimens guidelines on the drawing of target volumes (TV) are available.
Guidelines in extremity sarcomas (ES) are lacking up to now.
The EORTC develops a new phase III trial on pre- versus postoperative irradiation in ES patients.
A task force is currently producing uniform guidelines for drawing TV in ES patients.
Methods
Experts in the field of radiotherapy in sarcomas were selected.
A draft guideline was produced (by chair).
A CD-ROM with 4 ES cases (2 pre-op, 2 post-op)
containing the planning CT-scan3-dimensional diagnostic MRI imagingpatient characteristicsdrawing tool.
Methods; volumes to be drawn.
Pre-op cases: GTV, CTV and PTV
Post-op cases: first-phase CTV and PTVboost CTV and PTV
Phases of target volume guideline development
1st phase
Concept guideline by chair
1st round CD a/ drawing according to concept guideline
b/ any suggestions on the concept guideline
Phases of target volume guideline development
1st phase
Concept guideline by chair
1st round CD a/ drawing according to concept guideline=> are RT’s able to produce uniform TV
b/ any suggestions on the concept guideline
Phases of target volume guideline development
1st phase
Concept guideline by chair: drawing of the primary tumor = GTV
femur
MRItumor
volume=GTV
femur
MRItumor
volume=GTV fem
ur
MRItumor
volume=GTV
femu
rfem
ur
MRItumor
volume=GTV
Phases of target volume guideline development
1st phase
Concept guideline by chair: drawing of the possible microscopic extensions = CTV
femur
1.5cm
Less than 1.5cm, femur not involved!
=CTV1.0cm
femur
1.5cm
Less than 1.5cm, femur not involved!
=CTV1.0cm
femu
r
=CTV
Less than 1.5cm, femur not involved!
1.5cm
1.5cm
3cm
3cm
femu
rfem
ur
=CTV
Less than 1.5cm, femur not involved!
1.5cm
1.5cm
3cm
3cm
Phases of target volume guideline development
1st phase
Concept guideline by chair; drawing of the volume to be irradiated = PTV
femur
=PTV
1.0cm
femur
=PTV
1.0cm
femur
=PTV
1.0cm
1.0cm
femur
femur
=PTV
1.0cm
1.0cm
Phases of target volume guideline development
2nd phase
2nd round CD inter-observer variations
intra-observer variations
interval several months
Phases of target volume guideline development
2nd phase
2nd round CD inter-observer variations
intra-observer variations
Interval several months
2nd version guideline margins
concepts
etc etc
Phases of target volume guideline development
3rd phase
Final version guideline
3rd round CD drawing of TV exactly according to final guideline
interobserver variability
First results
Golden Rule: two doctors seldom agree on one subject
I think we’ll need a third opinion. My computer and I seem to disagree.
First results; disagreement
Conformity index
= common volume
= encompassing volume
Observer A Observer B
First results; disagreement
Conformity index
= common volume
= encompassing volume
Observer A Observer B
First results; disagreement
Conformity index Ideal situation Poor situation
common volume = “pure” GTV = zero cc
encompassing volume = common volume = ~ 2x “pure” GTV
First results; disagreement
Conformity index Ideal situation Worst situation
common volume = “pure” GTV = zero cc
encompassing volume = common volume = ~ 2x “pure” GTV
First results; disagreement;
Common volume
Encompassing
volume
Ratio
Pre-op case GTV 59 114 1.93
CTV 329 515 1.56
PTV 599 1060 1.77
Post-op case CTV 1st phase 841 1877 2.23
PTV 1st phase 1594 3161 1.98
CTV boost 516 1550 3.00
PTV boost 984 2539 2.58
First results; disagreement;
Conclusions volumes in post-op RT are much larger disagreement in post-op RT is much larger
Common volume
Encompassing
volume
Ratio
Pre-op case GTV 59 114 1.93
CTV 329 515 1.56
PTV 599 1060 1.77
Post-op case CTV 1st phase 841 1877 2.23
PTV 1st phase 1594 3161 1.98
CTV boost 516 1550 3.00
PTV boost 984 2539 2.58