Total Lesion Glycolysis by 18F-FDG PET/CT a Reliable Predictor of Prognosis

in Soft Tissue Sarcoma

Ilkyu Han

Musculoskeletal Tumor Center, Seoul National University Cancer Hospital, Seoul, Korea

- CTOS 2013 -

Total Lesion Glycolysis by 18F-FDG PET/CT a Reliable Predictor of Prognosis

in Soft Tissue Sarcoma

Ilkyu Han

Musculoskeletal Tumor Center, Seoul National University Cancer Hospital, Seoul, Korea

- CTOS 2013 -

Nothing to Disclose

• Soft tissue sarcoma

: Diverse subtypes and aggressiveness

→ Complicates the prediction of disease progression

• Further improvement of prognostication is warranted, be-sides conventional staging systems and nomograms

• Morphological imaging (MRI or CT)

: Limited capacity for assessment of malignant capacity

Prognosis in Soft Tissue Sarcoma

• Functional imaging by evaluating tumor glucose metabolism

• Established role

: Monitoring primary tumors, lymph nodes and metastases

• Potential role Histological characteristics Tumor response to treatment Oncological outcomes

18F-FDG PET/CT18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

SUVmax• Maximum standardized uptake value • Represents only the most active spot of the tumor

Soft tissue sarcoma • Heterogeneity within the tumor• Size of tumor

SUVmax = 3.1 Size = 20cmSUVmax = 7.2 Size = 7cm

Volume-based Parameters• Metabolic Tumor Volume (MTV)

Volume of voxels with SUV > threshold value (cm3)

• Total Lesion Glycolysis (TLG)

MTV x SUVmean

Volume-based Parameters• Metabolic Tumor Volume (MTV)

Volume of voxels with SUV > threshold value (cm3)

• Total Lesion Glycolysis (TLG)

MTV x SUVmean

SUVmax : 11.4

Volume-based Parameters

SUVmax : 11.4

MTV 1) 56 cm3 (Threshold SUV: 5.0)2) 152 cm3 (Threshold SUV: 2.5)

• Metabolic Tumor Volume (MTV)

Volume of voxels with SUV > threshold value (cm3)

• Total Lesion Glycolysis (TLG)

MTV x SUVmean

Volume-based Parameters

SUVmax : 11.4

MTV 1) 56 cm3 (Threshold SUV: 5.0)2) 152 cm3 (Threshold SUV: 2.5) TLG 152 x 5.15 (SUVmean) = 782.8

• Metabolic Tumor Volume (MTV)

Volume of voxels with SUV > threshold value (cm3)

• Total Lesion Glycolysis (TLG)

MTV x SUVmean

• Prognosis MTV

Ovarian, head and neck, non small cell lung cancer TLG

Colorectal, Breast, B cell lymphoma

• In soft tissue sarcoma Monitoring tumor response: TLG < SUVmax Few reports on volume based PET parameters

Volume-based Parameters & Prognosis

• Compare the volume-based parameters

of TLG and MTV with SUVmax

in predicting disease progression of STS

Purpose

• Review of 94 patients with FDG PET/CT before cura-tive surgery of STS of extremities

• Exclusion Criteria• Previous diagnosis of another malignancy (n=3)• Diabetes (4)• Less than 6 months follow-up (9)• Well differentiated liposarcoma (12)

• 66 patients analyzed

Patient Cohort

• Demographics

Patient Characteristics

• Tumor

• Treatment

• PET/CT Scanners Gemini, Philips Medical Systems, Milpitas, CA, USA Biograph 40, Siemens Medical Solutions, Knoxville, TN, USA

• Measurement of SUVmax, MTV and TLG Automated volume-contouring program (Synogo.via,

Siemens)

: Avoid interobserver and intraobserver bias Two nuclear medicine physicians blinded to clinical informa-

tion analyzed all images.

PET-CT

• Clinical endpoint: Progression-free survival Distant metastases or local recurrence by 2 years Histological or unequivocal clinical evidence

• Receiver operating characteristics Accuracy of the parameters Best discriminating cut-off values for parameters

Prognostic Value of Parameters

Results

ROC Curve Analysis

• AUC: TLG 0.833 > SUVmax 0.771 > MTV 0.667

• Cut-off values: TLG 20, SUVmax 6.0, MTV 40cm3

Progression-free Survival

TLGp=0.001

MTVp=0.031

SUVmaxp=0.022

• All 3 parameters were identified as significant prognostic factors for disease progression by log rank test.

Univariate Analysis

• Size, Stage, Margin, Initial Metastasis + SUVmax, TLG, MTV

Multivariate Analysis

• Stage, Initial Metastasis + TLG

→ TLG is an independent prognostic factor

Representative Case

• Myxoid Liposarcoma, Grade II, 20cm

• SUVmax: 3.07, TLG : 463

• Metastases developed.

Summary

• This the first study to examine the prognostic roles of PET-based metabolic parameters of tumor burden, using MTV and TLG in STS.

Summary

• This the first study to examine the prognostic roles of PET-based metabolic parameters of tumor burden, using MTV and TLG in STS.

• TLG exhibited greater accuracy for predicting disease pro-gression than SUVmax or MTV in ROC analysis.

Summary

• This the first study to examine the prognostic roles of PET-based metabolic parameters of tumor burden, using MTV and TLG in STS.

• TLG exhibited greater accuracy for predicting disease pro-gression than SUVmax or MTV in ROC analysis.

• TLG was independent prognostic factor in multivariate anal-ysis along with presence of metastasis at diagnosis.

Conclusion

• TLG, which combines metabolic and volumetric indices,

may be a more accurate predictor of progression-free sur-

vival in STS than MTV or SUVmax.

Conclusion

• TLG, which combines metabolic and volumetric indices,

may be a more accurate predictor of progression-free sur-

vival in STS than MTV or SUVmax.

• TLG enables preoperative assessment of disease progres-

sion with an accuracy comparable to those of conventional

clinicopathological parameters.

• Orthopaedic Surgery

Eun-Seok Choi

Han-Soo Kim

• Nuclear Medicine

Jin Chul Paeng

Seung-Gyun Ha

Thank you for your attention!

• Orthopaedic Surgery

Eun-Seok Choi

Han-Soo Kim

• Nuclear Medicine

Jin Chul Paeng

Seung-Gyun Ha