Table 1.
List of heterogeneity and shape indices.
Table 2.
Patients’ characteristics.
Table 3.
Semi-quantitative metrics derived from initial FDG-PET.
Table 4.
Prognostic values (p value and Hazard Ratios when p-value < 0.05) of classical prognostic factors derived from initial staging and of metrics derived from initial FDG-PET, on univariate analysis.
Table 5.
Prognostic values (p value and Hazard Ratios when significant p-value) of classical prognostic factors derived from initial staging and of metrics derived from initial FDG-PET, on multivariate analysis.
Fig 1.
Shape elongation’s measure is based on the ratio of the longer and shorter edges of the minimum area bounding rectangle for the measured shape. An elongation factor of 1 represents an ideal case with maximum symmetry. Thus, in example (A), in a patient with Ewing Sarcoma of the left tibia, the elongation factor measured on the initial FDG-PET scan was 1.32. Greater values express greater elongation of the ROI volume such as in example (B) in a patient with osteosarcoma of the left tibia with an elongation factor of 2.68.
Table 6.
Semi-quantitative metrics derived from post-CHT FDG-PET.
Fig 2.
Various explorations conducted in a patient with osteosarcoma of the right upper arm.
A 14-year-old girl with osteosarcoma of the right upper arm visualized by FDG-PET scans acquired before chemotherapy (A) and after chemotherapy (B) (left column, coronal view of PET; second column, fused PET/CT; third column, CT images; fourth column, the maximum intensity projections of PET; right column, local MRI unenhanced T1- weighted). After neoadjuvant chemotherapy (B), local MRI showed a stable tumor size and FDG-PET remained similar to baseline. Despite this stable disease on imaging, the removed tumor specimen (C) was almost completely composed of necrotic tissue (96%).
Fig 3.
Various explorations conducted in a patient with osteosarcoma of the right tibia.
FDG-PET scans acquired before (A) and after chemotherapy (B) in a patient with osteosarcoma of the right tibia. The maximum intensity projections of PET (first columns) and the coronal views of fused PET/CT images (third columns) showed evident significant reduction in MTV (second columns) using an adaptative threshold, after chemotherapy. The removed tumor specimen (C) was almost completely composed of necrotic tissue (99%).