11

RTOG Sarcoma Working Group Consensus RTOG Sarcoma Working Group Consensus on The GTV and CTV For Preoperative on The GTV and CTV For Preoperative

Radiotherapy of Large High Grade Extremity Radiotherapy of Large High Grade Extremity Soft Tissue Sarcoma Soft Tissue Sarcoma

Dian Wang, MD., Ph.D.Dian Wang, MD., Ph.D.

Medical College of WisconsinMedical College of Wisconsin

RTOG Extremity Soft Tissue Sarcoma Atlas

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Definition of GTV and CTVDefinition of GTV and CTV• Gross Target Volume (GTV):Gross Target Volume (GTV): Gross tumor defined by MRI T1 plus Gross tumor defined by MRI T1 plus

contrast images (MRI with contrast is required). Fusion of MRI and CT contrast images (MRI with contrast is required). Fusion of MRI and CT is recommended to delineate the GTV for radiotherapy planning. is recommended to delineate the GTV for radiotherapy planning. Intravenous contrast is recommended, particularly for upper extremity Intravenous contrast is recommended, particularly for upper extremity lesions, where there is a greater rotational mobility and positioning lesions, where there is a greater rotational mobility and positioning fidelity between the diagnostic MRI and the planning CT may be more fidelity between the diagnostic MRI and the planning CT may be more difficult to achievedifficult to achieve

• Clinical Target Volume (CTV) for Clinical Target Volume (CTV) for intermediate-to-high grade intermediate-to-high grade sarcoma ≥ 5 cmsarcoma ≥ 5 cm: : Include gross tumor and clinical microscopic margins. Include gross tumor and clinical microscopic margins. Typically CTV = GTV plus 3 cm margins in the longitudinal (proximal Typically CTV = GTV plus 3 cm margins in the longitudinal (proximal and distal) directions. If this causes the field to extend beyond the and distal) directions. If this causes the field to extend beyond the compartment, the field can be shortened to include the end of a compartment, the field can be shortened to include the end of a compartment. The radial margin from the lesion should be 1.5 cm compartment. The radial margin from the lesion should be 1.5 cm including any portion of the tumor not confined by an intact fascial including any portion of the tumor not confined by an intact fascial barrier, bone or skin surface. The suspicious edema defined on MRI barrier, bone or skin surface. The suspicious edema defined on MRI T2 images is often included within the above margins. However, clinical T2 images is often included within the above margins. However, clinical judgment is required to make sure if the above margins need to be judgment is required to make sure if the above margins need to be extended to cover the T2 edema defined on MRI T2 images. For extended to cover the T2 edema defined on MRI T2 images. For example, the extensive T2 edema may be excluded if clinical judgment example, the extensive T2 edema may be excluded if clinical judgment suggests that the risk of the edema harboring sarcoma many cm suggests that the risk of the edema harboring sarcoma many cm beyond the GTV is low or if extending the radiation field to include all of beyond the GTV is low or if extending the radiation field to include all of the edema would cause excessive toxicity.the edema would cause excessive toxicity.

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Example Case Example Case

• 55-year-old male with a large high-grade 55-year-old male with a large high-grade round cell liposarcoma in right distal thigh. round cell liposarcoma in right distal thigh. Clinical stage (AJCC 7Clinical stage (AJCC 7thth edition) III edition) III T2bN0M0G3. T2bN0M0G3. – The MRI of right distal thigh showed a large well

circumscribed heterogeneous, multiloculated mass located within the posterior thigh.

– The tumor measured 14.8 cm in craniocaudal dimension, 7.8 cm in AP dimension, and 11.3 cm in maximal medial-lateral dimension.

• Simulation CT images were fused with those Simulation CT images were fused with those from the diagnostic thigh MRIfrom the diagnostic thigh MRI

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Consensus ContoursConsensus Contours

• The consensus contours for the GTV and CTV The consensus contours for the GTV and CTV were generated based on the modification of were generated based on the modification of the 95% agreement contours by RTOG the 95% agreement contours by RTOG Sarcoma Working Group Radiation Sarcoma Working Group Radiation OncologistsOncologists– Dian Wang, Walter Bosch, David Roberge, Steven E.

Finkelstein, Ivy Petersen, Michael Haddock, Yen-Lin E. Chen, Naoyuki G. Saito, David G. Kirsch, Ying J. Hitchcock, Aaron H. Wolfson, Thomas F. DeLaney. RTOG Sarcoma Radiation Oncologists Reach Consensus on Gross Tumor Volume (GTV) and Clinical Target Volume (CTV) on Computed Tomographic Images for Preoperative Radiotherapy of Primary Soft Tissue Sarcoma of Extremity in RTOG Studies. IJROBP June 2011

55

66

←CTV

77

←CTV

88

←CTV

99

←CTV

1010

←CTV

1111

←CTV

1212

←CTV

1313

←CTV

1414

←CTV

1515

←CTV

1616

←CTV

1717

←CTV

1818

GTV→ ←CTV

1919

GTV→ ←CTV

2020

GTV→ ←CTV

2121

GTV→ ←CTV

2222

GTV→ ←CTV

2323

GTV→ ←CTV

2424

GTV→ ←CTV

2525

GTV→ ←CTV

2626

GTV→ ←CTV

2727

GTV→ ←CTV

2828

GTV→ ←CTV

2929

GTV→ ←CTV

3030

GTV→ ←CTV

3131

GTV→ ←CTV

3232

GTV→ ←CTV

3333

GTV→ ←CTV

3434

GTV→ ←CTV

3535

GTV→ ←CTV

3636

GTV→ ←CTV

3737

GTV→ ←CTV

3838

GTV→ ←CTV

3939

GTV→ ←CTV

4040

GTV→ ←CTV

4141

GTV→ ←CTV

4242

GTV→ ←CTV

4343

GTV→ ←CTV

4444

GTV→ ←CTV

4545

GTV→ ←CTV

4646

GTV→ ←CTV

4747

GTV→

←CTV

4848

GTV→

←CTV

4949

GTV→

←CTV

5050

GTV→

←CTV

5151

GTV→

←CTV

5252

GTV→

←CTV

5353

GTV→

←CTV

5454

GTV→

←CTV

5555

GTV→

←CTV

5656

GTV→

←CTV

5757

GTV→

←CTV

5858

GTV→

←CTV

5959

GTV→

←CTV

6060

GTV→

←CTV

6161

GTV→

←CTV

6262

GTV→

←CTV

6363

GTV→

←CTV

6464

GTV→

←CTV

6565

GTV→

←CTV

6666

GTV→

←CTV

6767

GTV→

←CTV

6868

GTV→

←CTV

6969

GTV→

←CTV

7070

GTV→

←CTV

7171

GTV→

←CTV

7272

GTV→

←CTV

7373

GTV→

←CTV

7474

GTV→

←CTV

7575

GTV→

←CTV

7676

GTV→

←CTV

7777

GTV→

←CTV

7878

GTV→

←CTV

7979

GTV→

←CTV

8080

←CTV

8181

←CTV

8282

←CTV

8383

←CTV

8484

←CTV

8585

←CTV

8686

←CTV

8787

←CTV

8888

←CTV

8989

←CTV

9090

←CTV

9191