Volume-based 18F-FDG PET/CT imaging markers provide prognostic information beyond histologic grading – a retrospective study of 92 patients with high-grade bone or soft tissue sarcoma

Kim Francis Andersen1, Hanna Maria Fuglø2, Sine Hvid Rasmussen1, Michael Mørk Petersen2 & Annika Loft1

Department of Clinical Physiology, Nuclear Medicine & PET1 Department of Orthopedic Surgery2

Rigshospitalet, University of CopenhagenDenmark

Volume-based 18F-FDG PET/CT imaging markers provide prognostic information beyond histologic grading – a retrospective study of 92 patients with high-grade bone or soft tissue sarcoma

Kim Francis Andersen1, Hanna Maria Fuglø2, Sine Hvid Rasmussen1, Michael Mørk Petersen2 & Annika Loft1

Department of Clinical Physiology, Nuclear Medicine & PET1 Department of Orthopedic Surgery2

Rigshospitalet, University of CopenhagenDenmark

No disclosures

Background

• Potential benefits of 18F-FDG PET:- Staging- Treatment response evaluation- Oncological outcomes

• Difficult to standardize the implementation of this imaging modality in the diagnostic work-up and follow-up of patients with sarcoma

• Clinical evidence suffers to the low incidence of tumors as well as high intra- and inter-tumoral heterogeneity

• Pre-treatment estimation of SUVmax of the primary tumor in sarcoma patients has been suggested being a significant prognostic factor for overall and progression-free survival

Background

• SUVmax purely represents the maximum value of a single voxel in the acquired imaging data - it does not reflect important prognostic tumor properties such as:a) Tumor heterogeneityb) Tumor size and burden

Background

• SUVmax purely represents the maximum value of a single voxel in the acquired imaging data - it does not reflect important prognostic tumor properties such as:a) Tumor heterogeneityb) Tumor size and burden

• Volume-based 18F-FDG PET imaging markers:a) Metabolic tumor volume (MTV)b) Total lesion glycolysis (TLG):- MTV x (SUVmean of the MTV)

Background

• In sarcoma patients:a) Clinical evidence is minimal and conflicting

- TLG: predictor of progression-free survival in STS1

- Volume-based 18F-FDG PET imaging markers (MTV & TLG) may not provide additional prognostic information in STS2

b) Prognostic value of MTV and TLG in terms of overall survival in patients with BS?

1Choi et al. Eur J Nucl Med Mol Imaging 2013;40(12):1836-18422Hong et al. Skeletal Radiol 2014;43(5):641-8

Background

• In sarcoma patients:a) Clinical evidence is minimal and conflicting

- TLG: predictor of progression-free survival in STS1

- Volume-based 18F-FDG PET imaging markers (MTV & TLG) may not provide additional prognostic information in STS2

b) Prognostic value of MTV and TLG in terms of overall survival in patients with BS?

1Choi et al. Eur J Nucl Med Mol Imaging 2013;40(12):1836-18422Hong et al. Skeletal Radiol 2014;43(5):641-8

‘…to compare the prognostic value of volume-based semi-quantitative

calculations of primary tumor metabolic activity using 18F-FDG

PET/CT in the initial assessment of patients with high-grade bone or

soft-tissue sarcoma…’

Materials & methods

• Single-site study• Retrospective design• Inclusion period: July 1st 2002 – December 31st 2012

• Inclusion criteria:a) Histologically verified high-grade BS or STSb) No previous history of malignancyc) On-site pre-treatment 18F-FDG PET/CT scand) Follow-up period >12 months for survived patients

Materials & methods

• N=92 (37 BS; 55 STS)• 47 male; 45 female• Median age 49.8y • Median follow-up 2.8y

Materials & methods

• Pre-treatment 18F-FDG PET/CT scan• VOI of primary tumor• Metabolic tumor volume (MTV40%)• Total lesion glycolysis (TLG)• Clinical data acquired• Clinical endpoint: overall survival

Clinical characteristics

ROC curve analysis

Kaplan-Meier survival estimates

Cox proportional hazards regression analysis

All other variables included in the multivariate regression analysis failed to demonstrate independent prognostic properties in terms of overall survival:• Gender• Tumor size• Metastasis at diagnosis• MTV40%

Conclusion & future perspectives

In patients with high-grade sarcoma:• Estimation of pre-treatment total lesion glycolysis can be

recognized as an independent prognostic marker for overall survival

• Further studies are needed to demonstrate the clinical utility of volume-based 18F-FDG PET imaging markers, especially TLG

Conclusion & future perspectives

In patients with high-grade sarcoma:• Estimation of pre-treatment total lesion glycolysis can be

recognized as an independent prognostic marker for overall survival

• Further studies are needed to demonstrate the clinical utility of volume-based 18F-FDG PET imaging markers, especially TLG

• Tumor heterogenity? Asphericity?• PET/MRI? Hyperpolarization?• Tumor-specific tracers?

Thank you for your

attention!

SUVmax vs. total lesion glycolysis (TLG)

TLG:• High-significant, slightly larger AUC• Increased sensitivity• Unchanged specificity• High-significant differences in average survival; hazard ratios higher• Contrary to SUVmax, TLG remained an independent prognostic factor

for overall survival during subgroup analysis