ON THE DEVELOPMENT OF TARGET VOLUME GUIDELINES IN EXTREMITY SARCOMAS; WORK IN PROGRESS BY A TRANSATLANTIC RADIATION-ONCOLOGISTS TASK FORCE. Rick Haas NKI – 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 :

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 radiotherapy J. Staffurth; ASCO

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 / 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-scan 3-dimensional diagnostic MRI imaging patient characteristics drawing tool.

Methods; volumes to be drawn. Pre-op cases: GTV, CTV and PTV Post-op cases:first-phase CTV and PTV boost CTV and PTV

CD-ROM

Phases of target volume guideline development 1 st phase Concept guideline by chair 1 st round CDa/ drawing according to concept guideline b/ any suggestions on the concept guideline

Phases of target volume guideline development 1 st phase Concept guideline by chair 1 st round CDa/ 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 1 st phase Concept guideline by chair: drawing of the primary tumor = GTV

Phases of target volume guideline development 1 st phase Concept guideline by chair: drawing of the possible microscopic extensions = CTV

Phases of target volume guideline development 1 st phase Concept guideline by chair; drawing of the volume to be irradiated = PTV

Phases of target volume guideline development 2 nd phase 2 nd round CDinter-observer variations intra-observer variations interval several months

Phases of target volume guideline development 2 nd phase 2 nd round CDinter-observer variations intra-observer variations Interval several months 2 nd version guidelinemargins concepts etc

Phases of target volume guideline development 3 rd phase Final version guideline 3 rd round CDdrawing 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 indexIdeal situationPoor situation common volume= “pure” GTV= zero cc encompassing volume= common volume= ~ 2x “pure” GTV

First results; disagreement Conformity indexIdeal situationWorst situation common volume= “pure” GTV= zero cc encompassing volume= common volume= ~ 2x “pure” GTV

First results; disagreement;

Conclusions volumes in post-op RT are much larger disagreement in post-op RT is much larger

Thanks for your attention