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

CD-ROM

CD-ROM

CD-ROM

CD-ROM

CD-ROM

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; agreement

First results; disagreement

Conformity index

Observer A Observer B

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

Thanks for your attention