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
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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