total lesion glycolysis by 18 f-fdg pet/ct a reliable predictor of prognosis in soft tissue sarcoma...
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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
• 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
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.
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.